Differential Penicillin-Binding Protein 5 (PBP5) Levels in the Enterococcus faecium Clades with Different Levels of Ampicillin Resistance.

PubMed

Montealegre, Maria Camila; Roh, Jung Hyeob; Rae, Meredith; Davlieva, Milya G; Singh, Kavindra V; Shamoo, Yousif; Murray, Barbara E

2017-01-01

Ampicillin resistance in Enterococcus faecium is a serious concern worldwide, complicating the treatment of E. faecium infections. Penicillin-binding protein 5 (PBP5) is considered the main ampicillin resistance determinant in E. faecium The three known E. faecium clades showed sequence variations in the pbp5 gene that are associated with their ampicillin resistance phenotype; however, these changes alone do not explain the array of resistance levels observed among E. faecium clinical strains. We aimed to determine if the levels of PBP5 are differentially regulated between the E. faecium clades, with the hypothesis that variations in PBP5 levels could help account for the spectrum of ampicillin MICs seen in E. faecium We studied pbp5 mRNA levels and PBP5 protein levels as well as the genetic environment upstream of pbp5 in 16 E. faecium strains that belong to the different E. faecium clades and for which the ampicillin MICs covered a wide range. Our results found that pbp5 and PBP5 levels are increased in subclade A1 and A2 ampicillin-resistant strains compared to those in clade B and subclade A2 ampicillin-susceptible strains. Furthermore, we found evidence of major clade-associated rearrangements in the region upstream of pbp5, including large DNA fragment insertions, deletions, and single nucleotide polymorphisms, that may be associated with the differential regulation of PBP5 levels between the E. faecium clades. Overall, these findings highlight the contribution of the clade background to the regulation of PBP5 abundance and point to differences in the region upstream of pbp5 as likely contributors to the differential expression of ampicillin resistance. Copyright © 2016 American Society for Microbiology.

Pharmacokinetics of an ampicillin-sulbactam combination after intravenous and intramuscular administration to sheep.

PubMed Central

Escudero, E; Espuny, A; Vicente, S; Cárceles, C M

1999-01-01

The pharmacokinetics of a 2:1 ampicillin-sulbactam combination were studied in 6 sheep, after intravenous and intramuscular injection at a single dose rate of 20 mg/kg body weight (13.33 mg/kg of sodium ampicillin and 6.67 mg/kg of sodium sulbactam). The drugs were distributed according to an open 2-compartment model after intravenous administration and a one-compartment model with first order absorption after intramuscular administration. The apparent volumes of distribution calculated by the area method of ampicillin and sulbactam were 0.32+/-0.06 L/kg and 0.42+/-0.04 L/kg, respectively and the total body clearances were 0.69+/-0.07 and 0.38+/-0.03 L/kg x h, respectively. The elimination half-lives of ampicillin after intravenous and intramuscular administration were 0.32+/-0.05 h and 0.75+/-0.27 h, respectively, whereas for sulbactam the half-lives were 0.74+/-0.10 h and 0.89+/-0.16 h, respectively. The bioavailability after intramuscular injection was high and similar in both drugs (72.76+/-9.65% for ampicillin and 85.50+/-8.35% for sulbactam). The mean peak plasma concentrations of ampicillin and sulbactam were reached at similar times (0.25+/-0.10 h and 0.24+/-0.08 h, respectively) and peak concentrations were also similar but nonproportional to the dose of both products administered (13.01+/-7.36 mg/L of ampicillin and 10.39+/-3.95 mg/L of sulbactam). Both drugs had a similar pharmacokinetic behavior after intramuscular administration in sheep. Since the plasma concentrations of sulbactam where consistently higher during the elimination phase of their disposition, consideration could be given to formulating the ampicillin-sulbactam combination in a higher than 2:1 ratio. PMID:9918330

High nasopharyngeal carriage of beta-lactamase-negative ampicillin-resistant Haemophilus influenzae in north Indian school-going children.

PubMed

Jain, Amita; Kumar, Pradeep; Agarwal, Sudhir K

2008-02-01

Development of ampicillin resistance in Haemophilus influenzae is a cause of serious concern. Ampicillin resistance in H influenzae is beta-lactamase mediated except in some isolates. Two important issues related to beta-lactamase-negative ampicillin-resistant (BLNAR) strains while choosing therapy for infections caused by H. influenzae are (i) whether BLNAR H. influenzae isolates are sufficiently pathogenic to cause respiratory tract infection, and (ii) variability in the magnitude of ampicillin minimum inhibitory concentrations obtained for the isolates. The aim of the present study was to determine the carriage of BLNAR H. influenzae in the nasopharynx of normal healthy children, to test the level of ampicillin resistance and the correlation of ampicillin resistance with resistance to other antimicrobials and to evaluate the frequency of serotype b and biotypes I, II, and III among BLNAR H. influenzae. Of 1001 H. influenzae isolates, 229 (22.9%) strains were ampicillin resistant. A total of 33/229 isolates were BLNAR. beta-Lactamase-positive strains show higher level of resistance to ampicillin as well as to chloramphenicol, erythromycin, and co-trimoxazole. Of the 196 beta-lactamase-producing H. influenzae isolates, 112 (57%) were H. influenzae type b, while of the 33 BLNAR isolates, 27 (81.8%) were H. influenzae type b. One hundred and eighty-four of 196 (93.9%) beta-lactamase-producing H. influenzae isolates and 30/33 (91.0%) BLNAR strains belonged to biotypes I, II, and III. BLNAR H. influenzae are no less pathogenic than beta-lactamase-positive H. influenzae. Higher level of drug resistance was found in beta-lactamase-producing H. influenzae in comparison to BLNAR isolates.

Minimizing human infection from Escherichia coli O157:H7 using GUMBOS

PubMed Central

Cole, Marsha R.; Li, Min; Jadeja, Ravirajsinh; El-Zahab, Bilal; Hayes, Daniel; Hobden, Jeffery A.; Janes, Marlene E.; Warner, Isiah M.

2013-01-01

Objectives Reduction in faecal shedding of Shiga toxin-producing enterohaemorrhagic Escherichia coli (EHEC) in food-producing animals is a viable strategy to minimize human disease initiated by exposure to these microorganisms. To this end, an intervention strategy involving the electrostatic hybridization of two commonly used anti-infective agents for veterinary practice (i.e. chlorhexidine and ampicillin) was evaluated to curtail EHEC-transmitted disease from ruminant sources. Chlorhexidine di-ampicillin is a novel group of uniform material based on organic salts (GUMBOS) with inherent in vitro antibacterial activity that comes from its parent antimicrobial ions, chlorhexidine and ampicillin. Methods Antibacterial activities for chlorhexidine diacetate, sodium ampicillin, chlorhexidine di-ampicillin and stoichiometrically equivalent 1 : 2 chlorhexidine diacetate : sodium ampicillin were assessed using the serial 2-fold dilution method and time–kill studies against seven isolates of E. coli O157:H7 and one non-pathogenic E. coli 25922. Further studies to investigate synergistic interactions of reacted and stoichiometrically equivalent unreacted antimicrobial agents at MICs and possible mechanisms were also investigated. Results Synergism and in vitro antibacterial activities against EHEC were observed in this study, which suggests chlorhexidine di-ampicillin could be a useful reagent in reducing EHEC transmission and minimizing EHEC-associated infections. Likewise, chlorhexidine di-ampicillin reduced HeLa cell toxicity as compared with chlorhexidine diacetate or the stoichiometric combination of antimicrobial agents. Further results suggest that the mechanisms of action of chlorhexidine di-ampicillin and chlorhexidine diacetate against E. coli O157:H7 are similar. Conclusions Reacting antimicrobial GUMBOS as indicated in this study may enhance the approach to current combination drug therapeutic strategies for EHEC disease control and prevention. PMID:23447139

Minimizing human infection from Escherichia coli O157:H7 using GUMBOS.

PubMed

Cole, Marsha R; Li, Min; Jadeja, Ravirajsinh; El-Zahab, Bilal; Hayes, Daniel; Hobden, Jeffery A; Janes, Marlene E; Warner, Isiah M

2013-06-01

Reduction in faecal shedding of Shiga toxin-producing enterohaemorrhagic Escherichia coli (EHEC) in food-producing animals is a viable strategy to minimize human disease initiated by exposure to these microorganisms. To this end, an intervention strategy involving the electrostatic hybridization of two commonly used anti-infective agents for veterinary practice (i.e. chlorhexidine and ampicillin) was evaluated to curtail EHEC-transmitted disease from ruminant sources. Chlorhexidine di-ampicillin is a novel group of uniform material based on organic salts (GUMBOS) with inherent in vitro antibacterial activity that comes from its parent antimicrobial ions, chlorhexidine and ampicillin. Antibacterial activities for chlorhexidine diacetate, sodium ampicillin, chlorhexidine di-ampicillin and stoichiometrically equivalent 1 : 2 chlorhexidine diacetate : sodium ampicillin were assessed using the serial 2-fold dilution method and time-kill studies against seven isolates of E. coli O157:H7 and one non-pathogenic E. coli 25922. Further studies to investigate synergistic interactions of reacted and stoichiometrically equivalent unreacted antimicrobial agents at MICs and possible mechanisms were also investigated. Synergism and in vitro antibacterial activities against EHEC were observed in this study, which suggests chlorhexidine di-ampicillin could be a useful reagent in reducing EHEC transmission and minimizing EHEC-associated infections. Likewise, chlorhexidine di-ampicillin reduced HeLa cell toxicity as compared with chlorhexidine diacetate or the stoichiometric combination of antimicrobial agents. Further results suggest that the mechanisms of action of chlorhexidine di-ampicillin and chlorhexidine diacetate against E. coli O157:H7 are similar. Reacting antimicrobial GUMBOS as indicated in this study may enhance the approach to current combination drug therapeutic strategies for EHEC disease control and prevention.

Determination of residual solvents and investigation of their effect on ampicillin trihydrate crystal structure.

PubMed

Nojavan, Saeed; Ghassempour, Alireza; Bashour, Yosef; Darbandi, Masoud Khalilian; Ahmadi, Seyyed Hamid

2005-01-04

In the present work, the relationship between residual solvents concentration and ampicillin trihydrate crystals stability has been investigated. The amounts of residual solvents determined by GC, X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FT-IR) were used for characterization of solid state. The obtained results have shown good relationship between concentration of methylene chloride (as a critical residue solvent) and degree of ampicillin trihydrate crystallinity. As with the increasing methylene chloride concentration in the sample the degree of crystallinity decreased after stability test. From this relationship, critical concentration of methylene chloride into the ampicillin trihydrate is obtained and the results can be used for improving the large-scale production of ampicillin trihydrate.

Early in vitro development of daptomycin non-susceptibility in high-level aminoglycoside-resistant Enterococcus faecalis predicts the efficacy of the combination of high-dose daptomycin plus ampicillin in an in vivo model of experimental endocarditis.

PubMed

Pericàs, J M; García-de-la-Mària, C; Brunet, M; Armero, Y; García-González, J; Casals, G; Almela, M; Quintana, E; Falces, C; Ninot, S; Fuster, D; Llopis, J; Marco, F; Moreno, A; Miró, J M

2017-06-01

Previous studies showed development of daptomycin non-susceptibility (DNS: MIC >4 mg/L) in Enterococcus faecalis infections. However, no studies have assessed the efficacy of the combination of daptomycin/ampicillin against E. faecalis strains developing DNS in the experimental endocarditis (EE) model. To assess the in vitro and in vivo efficacy of daptomycin at 10 mg/kg/day, daptomycin/ampicillin and ampicillin/ceftriaxone against two high-level aminoglycoside-resistant E. faecalis strains, one developing DNS after in vitro exposure to daptomycin and another that did not (DS). Subculture of 82 E. faecalis strains from patients with endocarditis with daptomycin MICs, time-kill and in vivo experiments using the EE model. 33% of the strains (27 of 82) displayed DNS after subculture with daptomycin. Daptomycin MIC rose from 0.5-2 to 8-16 mg/L. In time-kill experiments, when using a high inoculum (10 8 cfu/mL), daptomycin/ampicillin was synergistic for one-third of DS strains and none of DNS strains, while ampicillin/ceftriaxone retained synergy in all cases. In the EE model, daptomycin did not significantly reduce cfu/g from vegetations compared with control against either strain, while daptomycin/ampicillin reduced significantly more cfu/g than daptomycin against the DS strain, but not against the DNS strain [2.9 (2.0-4.1) versus 6.1 (4.5-8.0); P  =   0.002]. Ampicillin/ceftriaxone was synergistic and bactericidal against both strains, displaying the same activity as daptomycin/ampicillin against the DS strain. Performance of an Etest for daptomycin MIC after subculture with daptomycin inhibitory doses on strains of high-level aminoglycoside-resistant E. faecalis endocarditis may be an easy test to predict the in vivo efficacy of daptomycin/ampicillin. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Screening municipal wastewater effluent and surface water used for drinking water production for the presence of ampicillin and vancomycin resistant enterococci.

PubMed

Taučer-Kapteijn, Maja; Hoogenboezem, Wim; Heiliegers, Laura; de Bolster, Danny; Medema, Gertjan

2016-07-01

The emergence of clinical enterococcal isolates that are resistant to both ampicillin and vancomycin is a cause of great concern, as therapeutic alternatives for the treatment of infections caused by such organisms are becoming limited. Aquatic environments could play a role in the dissemination of antibiotic resistant enterococci. This study investigated the presence of ampicillin and vancomycin resistant enterococci in the treated effluent of six wastewater treatment plants (WWTPs) and in surface water used as a source for drinking water production in the Netherlands. Membrane filtration in combination with selective media with ampicillin or vancomycin was applied to determine the presence of ampicillin resistant Enterococcus (ARE) and vancomycin resistant Enterococcus (VRE) species. Ampicillin resistant Enterococcus faecium (minimal inhibitory concentration (MIC) >16μg/mL; n=1033) was observed in all studied WWTP effluents. In surface water used for drinking water production (intake locations), no ARE or VRE were observed. At both types of location, intrinsic vancomycin resistant Pediococcus spp., Leuconostoc spp. and Lactobacillus spp. were isolated with the vancomycin medium. The ampicillin resistant E. faecium (AREfm) isolates (n=113) did not contain the vanA or vanB gene, but MIC testing for vancomycin showed intermediate vancomycin resistance (2-8μgmL(-1)) to occur in these AREfm strains. This study documents the discharge of ampicillin resistant E. faecium strains with intermediate vancomycin resistance by the WWTPs into the surface water, but no presence of these strains downstream at intake locations for drinking water production. Copyright © 2016 Elsevier GmbH. All rights reserved.

Efficacy and safety of Sultamicillin (Ampicillin/Sulbactan) and Amoxicillin/Clavulanic acid in the treatment of upper respiratory tract infections in adults--an open-label, multicentric, randomized trial.

PubMed

Ferreira, João Batista; Rapoport, Priscila Bogar; Sakano, Eulália; Kós, Arthur Octávio De Avila; Piltcher, Otávio B; Pignatari, Shirley Shizue Nagata; Pinheiro, Sebastião Diógenes; Mocellin, Marcos

2006-01-01

Upper respiratory tract infections are the most common causes of medical visits in children and adults, demanding massive use of antibiotics. Bacterial resistance caused by beta-lactamase is one of the most serious problems in this matter. Sultamicillin, a double pro-drug of Ampicillin/Sulbactan, is a potent beta-lactamase inhibitor which can face this challenge. Evaluate efficacy, safety and tolerability of Ampicillin/Sulbactan compared to Amoxicillin/Clavulanate in upper respiratory tract infections in adults. 102 patients were enrolled and randomized to receive Ampicillin/Sulbactan or Amoxicillin/Clavulanate during 10 days. They were evaluated 10 and 30 days after treatment to learn about the therapeutic response. There were no differences between the two groups respecting cure at the end of treatment (visit 2) or at the end of the study (visit 3). Cure ratio was 61.7% and 93.2% (visits 2 and 3) in the Amoxicillin/Clavulanate group compared to 64.4% and 97.4%, respectively, in Ampicillin/Sulbactan group. The adverse events ratio for the two groups was the same (p=0.940). The number of patients with diarrhea was greater in the group of patients receiving Amoxicillin/Clavulanate (70.6%) than in the group receiving Ampicillin/Sulbactan (29.4%) (p=0.0164). Ampicillin/Sulbactan is as safe and efficient as Amoxicillin/Clavulanate in the empiric treatment of upper respiratory infections in adults. The low occurrence of diarrhea in the group receiving Ampicillin/Sulbactan needs confirmation in other studies.

21 CFR 520.90 - Ampicillin oral dosage forms.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ampicillin oral dosage forms. 520.90 Section 520.90 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90 Ampicillin oral...

21 CFR 520.90 - Ampicillin oral dosage forms.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ampicillin oral dosage forms. 520.90 Section 520.90 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90 Ampicillin oral...

21 CFR 520.90 - Ampicillin oral dosage forms.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ampicillin oral dosage forms. 520.90 Section 520.90 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90 Ampicillin oral...

21 CFR 520.90 - Ampicillin oral dosage forms.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ampicillin oral dosage forms. 520.90 Section 520.90 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90 Ampicillin oral...

Electrochemical oxidation of ampicillin antibiotic at boron-doped diamond electrodes and process optimization using response surface methodology.

PubMed

Körbahti, Bahadır K; Taşyürek, Selin

2015-03-01

Electrochemical oxidation and process optimization of ampicillin antibiotic at boron-doped diamond electrodes (BDD) were investigated in a batch electrochemical reactor. The influence of operating parameters, such as ampicillin concentration, electrolyte concentration, current density, and reaction temperature, on ampicillin removal, COD removal, and energy consumption was analyzed in order to optimize the electrochemical oxidation process under specified cost-driven constraints using response surface methodology. Quadratic models for the responses satisfied the assumptions of the analysis of variance well according to normal probability, studentized residuals, and outlier t residual plots. Residual plots followed a normal distribution, and outlier t values indicated that the approximations of the fitted models to the quadratic response surfaces were very good. Optimum operating conditions were determined at 618 mg/L ampicillin concentration, 3.6 g/L electrolyte concentration, 13.4 mA/cm(2) current density, and 36 °C reaction temperature. Under response surface optimized conditions, ampicillin removal, COD removal, and energy consumption were obtained as 97.1 %, 92.5 %, and 71.7 kWh/kg CODr, respectively.

High ampicillin resistance in different biotypes and serotypes of Haemophilus influenzae colonizing the nasopharynx of healthy school-going Indian children.

PubMed

Jain, Amita; Kumar, Pradeep; Awasthi, Shally

2006-02-01

Haemophilus influenzae is one of the main causes of otitis media, sinusitis, meningitis, pneumonia and septicaemia in children, and the development of ampicillin resistance in H. influenzae is a cause of serious concern. The aim of the present study was to determine the prevalence of ampicillin resistance in H. influenzae colonizing the nasopharynx of school-going healthy North Indian children, and to compare the distribution of different biotypes and serotype b in this population. A total of 2400 school-going healthy children from 45 rural and 45 urban schools were enrolled. Nasopharyngeal swabs were collected from the children and cultured. H. influenzae was isolated from 1001 (41.7 %) of the 2400 nasopharyngeal swabs collected. All these H. influenzae isolates were biotyped and serotyped, and their antibiotic susceptibility tested. All eight biotypes were present in this population. The most prevalent biotypes were I (19.6 %), II (16.8 %) and III (25.0 %). Of the 1001 isolates, 316 (31.6 %) were H. influenzae type b and 685 (68.4 %) were non-type b H. influenzae, and 22.9 % were resistant to ampicillin, 41.9 % to chloramphenicol, 27.5 % to erythromycin and 67.3 % to co-trimoxazole. Of the 316 H. influenzae type b isolates, 44.0 % were ampicillin resistant, while only 13.1 % non-type b H. influenzae isolates were ampicillin resistant. Of the 229 ampicillin-resistant H. influenzae isolates, 196 (85.6 %) were positive for beta-lactamase; 93.4 % (214/229) were biotypes I, II and III, of which 49 % were biotype I, 27.9 % were type II and 16.6 % were type III. Most of the strains belonging to biotypes III-VIII were ampicillin sensitive. Ampicillin resistance is significantly more common in biotype I and serotype b than in other biotypes and serotypes.

21 CFR 520.90d - Ampicillin trihydrate for oral suspension.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ampicillin trihydrate for oral suspension. 520.90d Section 520.90d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90d Ampicillin...

21 CFR 520.90d - Ampicillin trihydrate for oral suspension.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ampicillin trihydrate for oral suspension. 520.90d Section 520.90d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90d Ampicillin...

Susceptibility of Haemophilus influenzae Isolates from Blood and Cerebrospinal Fluid to Ampicillin, Chloramphenicol, and Trimethoprim-Sulfamethoxazole

PubMed Central

McGowan, John E.; Terry, Pamela M.; Nahmias, Andre J.

1976-01-01

Susceptibility to ampicillin and chloramphenicol in vitro has been determined for Haemophilus influenzae strains isolated from blood and/or cerebrospinal fluid cultures of patients admitted to two Atlanta hospitals from 1 January 1974 to 31 March 1975. Since the appearance of ampicillin-resistant strains of this organism in early 1974, chloramphenicol has been used in these hospitals as initial therapy for severe infection due to H. influenzae. Strains from five of 94 patients were resistant to ampicillin (minimum inhibitory concentration [MIC] ≥ 12.5 μg/ml), but all strains were susceptible to chloramphenicol (MIC < 2 μg/ml). The first 35 strains studied, including three resistant to ampicillin, were also tested for in vitro susceptibility to trimethoprim-sulfamethoxazole; all were highly susceptible (MIC ≤ 0.0312 μg of trimethoprim and 0.625 μg of sulfamethoxazole per ml). PMID:1083198

Rapid determination of ampicillin in bovine milk by liquid chromatography with fluorescence detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ang, C.Y.W.; Luo, Wenhong

1997-01-01

A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of ampicillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deproteinized with trichloroacetic acid (TCA) and acetonictrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5, 10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limitsmore » of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb. 16 refs., 4 figs., 3 tabs.« less

Typhoid outbreak in Kingston, Ont: experience with high-dose oral ampicillin.

PubMed Central

Hardy, G.; Padfield, C. J.; Chadwick, P.; Partington, M. W.

1977-01-01

Twenty-four children contracted typhoid fever at a summer camp near Kingston, Ont. Six were treated with chloramphenicol alone and 15 with high doses of ampicillin (300 mg/kg-d) by mouth. Ampicillin in this dosage was well tolerated except in three children in whom severe urticarial rashes developed and two who had significant diarrhea. However, high-dose oral ampicillin therapy had no advantage over that with lower doses or over chloramphenicol as judged by the rate of defervescence after the start of treatment, the rate of clinical relapse and the frequency of excretion of Salmonella typhi during convalescence. PMID:849559

Ammonia produced by bacterial colonies promotes growth of ampicillin-sensitive Serratia sp. by means of antibiotic inactivation.

PubMed

Cepl, Jaroslav; Blahůšková, Anna; Cvrčková, Fatima; Markoš, Anton

2014-05-01

Volatiles produced by bacterial cultures are known to induce regulatory and metabolic alterations in nearby con-specific or heterospecific bacteria, resulting in phenotypic changes including acquisition of antibiotic resistance. We observed unhindered growth of ampicillin-sensitive Serratia rubidaea and S. marcescens on ampicillin-containing media, when exposed to volatiles produced by dense bacterial growth. However, this phenomenon appeared to result from pH increase in the medium caused by bacterial volatiles rather than alterations in the properties of the bacterial cultures, as alkalization of ampicillin-containing culture media to pH 8.5 by ammonia or Tris exhibited the same effects, while pretreatment of bacterial cultures under the same conditions prior to antibiotic exposure did not increase ampicillin resistance. Ampicillin was readily inactivated at pH 8.5, suggesting that observed bacterial growth results from metabolic alteration of the medium, rather than an active change in the target bacterial population (i.e. induction of resistance or tolerance). However, even such seemingly simple mechanism may provide a biologically meaningful basis for protection against antibiotics in microbial communities growing on semi-solid media. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Ampicillin levels in sputum, serum, and saliva

PubMed Central

Stewart, Sheila M.; Fisher, Mary; Young, Joy E.; Lutz, W.

1970-01-01

The ampicillin levels in sputum, serum, and saliva from 40 patients receiving a dose of 250 mg., 26 patients receiving a dose of 500 mg., and 11 patients receiving a dose of 1 g. were estimated. The ampicillin was given orally four times daily. The 1-2 hour and 2-3 hour sputum levels were similar in individual patients. There was no difference in the range or mean sputum or saliva levels between specimens from patients receiving 250 mg. and 500 mg., but the levels were significantly higher after the 1 g. dose. The mean serum level showed a small increase after 500 mg. ampicillin as compared with the 250 mg. dose and a big increase after the 1 g. dose: only the latter difference was significant. The sputum levels were approximately 30 to 40 times lower than the corresponding serum levels. There was considerable scatter in the sputum level for any level of ampicillin in the serum: in only two of the 1-2 hour sputum specimens was there no detectable ampicillin. There was no correlation between the sputum levels and either the body weight or the dose in milligrams per kilogram. There was no evidence that corticosteroids or diuretics affected the sputum level. It was not possible to demonstrate any relationship between the purulence of the sputum and the level of ampicillin after doses of 250 mg. or 500 mg., but higher levels were found in the more purulent specimens after 1 g. doses. PMID:4318047

Antibacterial Compounds of Canadian Honeys Target Bacterial Cell Wall Inducing Phenotype Changes, Growth Inhibition and Cell Lysis That Resemble Action of β-Lactam Antibiotics

PubMed Central

Brudzynski, Katrina; Sjaarda, Calvin

2014-01-01

Honeys show a desirable broad spectrum activity against Gram-positive and negative bacteria making antibacterial activity an intrinsic property of honey and a desirable source for new drug development. The cellular targets and underlying mechanism of action of honey antibacterial compounds remain largely unknown. To facilitate the target discovery, we employed a method of phenotypic profiling by directly comparing morphological changes in Escherichia coli induced by honeys to that of ampicillin, the cell wall-active β-lactam of known mechanism of action. Firstly, we demonstrated the purity of tested honeys from potential β-lactam contaminations using quantitative LC-ESI-MS. Exposure of log-phase E. coli to honey or ampicillin resulted in time- and concentration-dependent changes in bacterial cell shape with the appearance of filamentous phenotypes at sub-inhibitory concentrations and spheroplasts at the MBC. Cell wall destruction by both agents, clearly visible on microscopic micrographs, was accompanied by increased permeability of the lipopolysaccharide outer membrane as indicated by fluorescence-activated cell sorting (FACS). More than 90% E. coli exposed to honey or ampicillin became permeable to propidium iodide. Consistently with the FACS results, both honey-treated and ampicillin-treated E. coli cells released lipopolysaccharide endotoxins at comparable levels, which were significantly higher than controls (p<0.0001). E. coli cells transformed with the ampicillin-resistance gene (β–lactamase) remained sensitive to honey, displayed the same level of cytotoxicity, cell shape changes and endotoxin release as ampicillin-sensitive cells. As expected, β–lactamase protected the host cell from antibacterial action of ampicillin. Thus, both honey and ampicillin induced similar structural changes to the cell wall and LPS and that this ability underlies antibacterial activities of both agents. Since the cell wall is critical for cell growth and survival, honey active compounds would be highly applicable for therapeutic purposes while differences in the mode of action between honey and ampicillin may provide clinical advantage in eradicating β-lactam-resistant pathogens. PMID:25191847

Determination of ampicillin sodium using the cupric oxide nanoparticles-luminol-H2 O2 chemiluminescence reaction.

PubMed

Iranifam, Mortaza; Kharameh, Merhnaz Khabbaz

2014-09-01

A simple and sensitive chemiluminescence (CL) method has been developed for the determination of ampicillin sodium at submicromolar levels. The method is based on the inhibitory effect of ampicillin sodium on the cupric oxide nanoparticles (CuO NPs)-luminol-H2 O2 CL reaction. Experimental parameters affecting CL inhibition including concentrations of CuO NPs, luminol, H2 O2 and NaOH were optimized. Under optimum conditions, the calibration plot was linear in the analyte concentration range 4.0 × 10(-7) -4.0 × 10(-6) mol/L. The limit of detection was 2.6 × 10(-7) mol/L and the relative standard deviation (RSD) for six replicate determinations of 1 × 10(-6) mol/L ampicillin sodium was 4.71%. Also, X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis were employed to characterize the CuO NPs. The utility of the proposed method was demonstrated by determining ampicillin sodium in pharmaceutical preparation. Copyright © 2013 John Wiley & Sons, Ltd.

The effects of the antibiotics ampicillin, florfenicol, sulfamethazine, and tylosin on biogas production and their degradation efficiency during anaerobic digestion.

PubMed

Mitchell, Shannon M; Ullman, Jeffrey L; Teel, Amy L; Watts, Richard J; Frear, Craig

2013-12-01

The impacts of four common animal husbandry antibiotics (ampicillin, florfenicol, sulfamethazine, and tylosin) on anaerobic digestion (AD) treatment efficiency and the potential for antibiotic degradation during digestion were evaluated. Sulfamethazine and ampicillin exhibited no impact on total biogas production up to 280 and 350 mg/L, respectively, although ampicillin inhibited biogas production rates during early stages of AD. Tylosin reduced biogas production by 10-38% between 130 and 913 mg/L. Florfenicol reduced biogas by ≈ 5%, 40% and 75% at 6.4, 36 and 210 mg/L, respectively. These antibiotic concentrations are higher than commonly seen for mixed feedlot manure, so impacts on full scale AD should be minimal. Antibiotic degradation products were found, confirming AD effectively degraded ampicillin, florfenicol, and tylosin, although some products were persistent throughout the process. Contamination of AD solid and liquid effluents with sulfamethazine and antibiotic transformation products from florfenicol and tylosin could present an environmental concern. Published by Elsevier Ltd.

Estimated Incidence of Antimicrobial Drug-Resistant Nontyphoidal Salmonella Infections, United States, 2004-2012.

PubMed

Medalla, Felicita; Gu, Weidong; Mahon, Barbara E; Judd, Michael; Folster, Jason; Griffin, Patricia M; Hoekstra, Robert M

2016-01-01

Salmonella infections are a major cause of illness in the United States. The antimicrobial agents used to treat severe infections include ceftriaxone, ciprofloxacin, and ampicillin. Antimicrobial drug resistance has been associated with adverse clinical outcomes. To estimate the incidence of resistant culture-confirmed nontyphoidal Salmonella infections, we used Bayesian hierarchical models of 2004-2012 data from the Centers for Disease Control and Prevention National Antimicrobial Resistance Monitoring System and Laboratory-based Enteric Disease Surveillance. We based 3 mutually exclusive resistance categories on susceptibility testing: ceftriaxone and ampicillin resistant, ciprofloxacin nonsusceptible but ceftriaxone susceptible, and ampicillin resistant but ceftriaxone and ciprofloxacin susceptible. We estimated the overall incidence of resistant infections as 1.07/100,000 person-years for ampicillin-only resistance, 0.51/100,000 person-years for ceftriaxone and ampicillin resistance, and 0.35/100,000 person-years for ciprofloxacin nonsusceptibility, or ≈6,200 resistant culture-confirmed infections annually. These national estimates help define the magnitude of the resistance problem so that control measures can be appropriately targeted.

Ampicillin/sulbactam and cefoxitin in the treatment of cutaneous and other soft-tissue abscesses in patients with or without histories of injection drug abuse.

PubMed

Talan, D A; Summanen, P H; Finegold, S M

2000-08-01

A randomized, double-blind trial compared the clinical and bacteriologic efficacy of ampicillin/sulbactam (2 g/1 g) and cefoxitin (2 g) administered intravenously every 6 h to patients with (n=49) or without (n=47) histories of injection drug abuse who presented with cutaneous or other soft-tissue infections. Cure or improvement occurred in 89.8% of ampicillin/sulbactam-treated patients, compared with 93.6% of cefoxitin-treated patients. The median time to resolution of all symptoms was 10.5 days with ampicillin/sulbactam treatment and 15.5 days with cefoxitin treatment. Mixed aerobic-anaerobic infection was encountered frequently in both treatment groups. A significantly higher percentage of Streptococcus species was found in the major abscesses of the patients with histories of injection drug abuse, compared with those without such histories (37% vs. 19%, respectively; P=.0009). Overall, ampicillin/sulbactam eradicated pathogens from the major abscesses in 100% of patients, whereas the eradication rate with cefoxitin was 97.9%. The 2 drugs were well tolerated. Ampicillin/sulbactam and cefoxitin were equally effective for the empirical treatment of cutaneous or other soft-tissue infections in injection drug abusers and patients who did not inject drugs.

Genome-Wide Identification of Ampicillin Resistance Determinants in Enterococcus faecium

PubMed Central

Zhang, Xinglin; Paganelli, Fernanda L.; Bierschenk, Damien; Kuipers, Annemarie; Bonten, Marc J. M.; Willems, Rob J. L.; van Schaik, Willem

2012-01-01

Enterococcus faecium has become a nosocomial pathogen of major importance, causing infections that are difficult to treat owing to its multi-drug resistance. In particular, resistance to the β-lactam antibiotic ampicillin has become ubiquitous among clinical isolates. Mutations in the low-affinity penicillin binding protein PBP5 have previously been shown to be important for ampicillin resistance in E. faecium, but the existence of additional resistance determinants has been suggested. Here, we constructed a high-density transposon mutant library in E. faecium and developed a transposon mutant tracking approach termed Microarray-based Transposon Mapping (M-TraM), leading to the identification of a compendium of E. faecium genes that contribute to ampicillin resistance. These genes are part of the core genome of E. faecium, indicating a high potential for E. faecium to evolve towards β-lactam resistance. To validate the M-TraM results, we adapted a Cre-lox recombination system to construct targeted, markerless mutants in E. faecium. We confirmed the role of four genes in ampicillin resistance by the generation of targeted mutants and further characterized these mutants regarding their resistance to lysozyme. The results revealed that ddcP, a gene predicted to encode a low-molecular-weight penicillin binding protein with D-alanyl-D-alanine carboxypeptidase activity, was essential for high-level ampicillin resistance. Furthermore, deletion of ddcP sensitized E. faecium to lysozyme and abolished membrane-associated D,D-carboxypeptidase activity. This study has led to the development of a broadly applicable platform for functional genomic-based studies in E. faecium, and it provides a new perspective on the genetic basis of ampicillin resistance in this organism. PMID:22761597

Effects of oils and pharmaceutical excipients on the bioavailability of ampicillin orally administered, different oily and aqueous suspensions in rabbit.

PubMed

Alhamami, Omran M O

2003-01-01

The in vivo bioavailability and in vitro drug-release studies of ampicillin trihydrate in different oily and aqueous suspensions have been investigated. In addition, partition, solubility, and rheological measurements have also been carried out. The in vivo experimental design was based on a 6 x 6 latin square using the rabbit as the test animal. The bioavailability of ampicillin was determined using the plasma levels, which were measured microbiologically. Results of the study showed that oily and sucrose-containing aqueous formulations enhanced the extent of ampicillin absorption, although not statistically significantly, but was close to the borderline of significance. Ampicillin appears to be absorbed at essentially the same rate from both aqueous and oily formulations. The latter showed plasma-level time curves with biphasic absorption and are likely to produce prolonged plasma concentrations of ampicillin because of the effects of enterohepatic recycling. Viscosity appears to play an insignificant role in the results obtained since the bioavailability parameters correlate poorly with the viscosity except Cmax. It is suggested that enhancement in the bioavailability of ampicillin is due to the decrease in the gut transit rate brought about by the oil which predominates and masks the other effects of viscosity and osmotic effects of sucrose. The existence of a correlation between the in vitro drug-release rate (t50%) and viscosity and the lack of a correlation between in vivo and in vitro parameters support the above suggestion and indicate that traditional dissolution rate tests, such as flask-stirrer method, are unsatisfactory as bioavailability indicators when applied to dosage forms that caused marked changes in physiological factors like GER and biliary excretion.

Cefoperazone compared with ampicillin plus tobramycin for severe biliary tract infections.

PubMed Central

Bergeron, M G; Mendelson, J; Harding, G K; Mandell, L; Fong, I W; Rachlis, A; Chan, R; Biron, S; Feld, R; Segal, N B

1988-01-01

In a prospective, randomized, multicenter study, the efficacy and safety of cefoperazone and the combination ampicillin-tobramycin as initial therapy for patients with severe acute biliary tract infections were compared. Of 77 patients initially entered in the study, definite severe biliary tract infection was confirmed in 67. Sixty-four patients completed treatment. At the end of treatment, 35 of 36 (97%) patients given cefoperazone and 23 of 28 (82%) given ampicillin-tobramycin were cured of their infection (P = 0.07). Pathogens were recovered from the bile in 32 patients; microbiological cures were observed in 18 of 19 (94%) patients receiving cefoperazone and 8 of 13 (62%) receiving ampicillin-tobramycin (P = 0.03). Thirteen patients had septicemia. None (0%) of the eight septicemic patients from the cefoperazone group, but two of five (40%) from the ampicillin-tobramycin group, were clinical failures. Of the isolated pathogens, 51% were resistant to ampicillin, while the resistance rate was 4% for tobramycin and 1% for cefoperazone (P less than 0.001). Biliary concentrations of cefoperazone were maintained at high levels--236 +/- 87 micrograms/ml up to 12 h after administration. Even in the presence of severe obstruction, cefoperazone levels in the bile and gallbladder wall were above MICs for most pathogens. Cefoperazone may be considered as an excellent alternative in the therapy of severe biliary tract infections. PMID:3056255

21 CFR 522.90b - Ampicillin trihydrate for suspension.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Treatment of respiratory tract infections caused by organisms susceptible to ampicillin, bacterial pneumonia (shipping fever, calf pneumonia, and bovine pneumonia) caused by Aerobacter spp., Klebsiella spp...

Estimated Incidence of Antimicrobial Drug–Resistant Nontyphoidal Salmonella Infections, United States, 2004–2012

PubMed Central

Gu, Weidong; Mahon, Barbara E.; Judd, Michael; Folster, Jason; Griffin, Patricia M.; Hoekstra, Robert M.

2017-01-01

Salmonella infections are a major cause of illness in the United States. The antimicrobial agents used to treat severe infections include ceftriaxone, ciprofloxacin, and ampicillin. Antimicrobial drug resistance has been associated with adverse clinical outcomes. To estimate the incidence of resistant culture-confirmed nontyphoidal Salmonella infections, we used Bayesian hierarchical models of 2004–2012 data from the Centers for Disease Control and Prevention National Antimicrobial Resistance Monitoring System and Laboratory-based Enteric Disease Surveillance. We based 3 mutually exclusive resistance categories on susceptibility testing: ceftriaxone and ampicillin resistant, ciprofloxacin nonsusceptible but ceftriaxone susceptible, and ampicillin resistant but ceftriaxone and ciprofloxacin susceptible. We estimated the overall incidence of resistant infections as 1.07/100,000 person-years for ampicillin-only resistance, 0.51/100,000 person-years for ceftriaxone and ampicillin resistance, and 0.35/100,000 person-years for ciprofloxacin nonsusceptibility, or ≈6,200 resistant culture-confirmed infections annually. These national estimates help define the magnitude of the resistance problem so that control measures can be appropriately targeted. PMID:27983506

Preparation and evaluation of effect on Escherichia coli and Staphylococcus aureus of radiolabeled ampicillin-loaded graphene oxide nanoflakes.

PubMed

Yurt, Fatma; Ersöz, Onur Alp; Harputlu, Ersan; Ocakoglu, Kasim

2018-06-01

Ampicillin is a one of effective antibiotics against Gram-positive and Gram-negative bacteria. This study aimed to label ampicillin-loaded graphene oxide nanoflake (AMP-GO) with 99m Tc and evaluate of its in vitro binding to Staphylococcus aureus and Escherichia coli. Firstly, ampicillin was loaded into graphene oxide nanoflake prepared. AMP-GO was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) techniques, and the amount of loaded ampicillin onto GO was determined by UV-Vis absorption spectroscopy. AMP and AMP-GO were labeled with 99m Tc using stannous chloride reducing agent. Labeling efficiency of 99m Tc-AMP-GO was found to be 97.66 ± 2.06%. 99m Tc-AMP-GO has higher binding efficiencies to both S. aureus and E. coli than 99m Tc-AMP. 99m Tc-AMP-GO could be promising candidate as agent infection nuclear imaging. Furthermore, in vivo studies of 99m Tc-AMP-GO with infected rats are planned to be performed. © 2018 John Wiley & Sons A/S.

Ampicillin Injection

MedlinePlus

... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to ampicillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin (Ancef, ...

Early transmissible ampicillin resistance in zoonotic Salmonella enterica serotype Typhimurium in the late 1950s: a retrospective, whole-genome sequencing study.

PubMed

Tran-Dien, Alicia; Le Hello, Simon; Bouchier, Christiane; Weill, François-Xavier

2018-02-01

Ampicillin, the first semi-synthetic penicillin active against Enterobacteriaceae, was released onto the market in 1961. The first outbreaks of disease caused by ampicillin-resistant strains of Salmonella enterica serotype Typhimurium were identified in the UK in 1962 and 1964. We aimed to date the emergence of this resistance in historical isolates of S enterica serotype Typhimurium. In this retrospective, whole-genome sequencing study, we analysed 288 S enterica serotype Typhimurium isolates collected between 1911 and 1969 from 31 countries on four continents and from various sources including human beings, animals, feed, and food. All isolates were tested for antimicrobial drug susceptibility with the disc diffusion method, and isolates shown to be resistant to ampicillin underwent resistance-transfer experiments. To provide insights into population structure and mechanisms of ampicillin resistance, we did whole-genome sequencing on a subset of 225 isolates, selected to maximise source, spatiotemporal, and genetic diversity. 11 (4%) of 288 isolates were resistant to ampicillin because of acquisition of various β lactamase genes, including bla TEM-1 , carried by various plasmids, including the virulence plasmid of S enterica serotype Typhimurium. These 11 isolates were from three phylogenomic groups. One isolate producing TEM-1 β lactamase was isolated in France in 1959 and two isolates producing TEM-1 β lactamase were isolated in Tunisia in 1960, before ampicillin went on sale. The vectors for ampicillin resistance were different from those reported in the strains responsible for the outbreaks in the UK in the 1960s. The association between antibiotic use and selection of resistance determinants is not as direct as often presumed. Our results suggest that the non-clinical use of narrow-spectrum penicillins (eg, benzylpenicillin) might have favoured the diffusion of plasmids carrying the bla TEM-1 gene in S enterica serotype Typhimurium in the late 1950s. Institut Pasteur, Santé publique France, the French Government's Investissement d'Avenir programme, the Fondation Le Roch-Les Mousquetaires. Copyright © 2018 Elsevier Ltd. All rights reserved.

SPR based hybrid electro-optic biosensor for β-lactam antibiotics determination in water

NASA Astrophysics Data System (ADS)

Galatus, Ramona; Feier, Bogdan; Cristea, Cecilia; Cennamo, Nunzio; Zeni, Luigi

2017-09-01

The present work aims to provide a hybrid platform capable of complementary and sensitive detection of β-lactam antibiotics, ampicillin in particular. The use of an aptamer specific to ampicillin assures good selectivity and sensitivity for the detection of ampicillin from different matrice. This new approach is dedicated for a portable, remote sensing platform based on low-cost, small size and low-power consumption solution. The simple experimental hybrid platform integrates the results from the D-shape surface plasmon resonance plastic optical fiber (SPR-POF) and from the electrochemical (bio)sensor, for the analysis of ampicillin, delivering sensitive and reliable results. The SPR-POF already used in many previous applications is embedded in a new experimental setup with fluorescent fibers emitters, for broadband wavelength analysis, low-power consumption and low-heating capabilities of the sensing platform.

Clinical microbiology laboratories do not always detect resistance of Haemophilus influenzae with disk or tablet diffusion methods. Finnish Study Group for Antimicrobial Resistance (FiRe).

PubMed

Manninen, R; Huovinen, P; Nissinen, A

1998-04-01

The performance of disk diffusion testing of Haemophilus influenzae was evaluated in 20 laboratories. Thirteen disk-medium-breakpoint-inoculum modifications were used in Finnish clinical microbiology laboratories. The performance of various methods was evaluated by testing a susceptible control strain and one with non-beta-lactamase-mediated ampicillin resistance 10 times in 16 laboratories. Gaps in millimeters were measured between these two groups of results. The strains were separated by a gap of at least 5 mm in 8/16 laboratories testing ampicillin, in 7/15 laboratories testing cefaclor, in 5/ 16 laboratories testing cefuroxime, and in 15/16 laboratories testing trimethoprim-sulfa. Detection of ampicillin resistance was better with 2.5 microg tablets than with 10 microg disks or 33 microg tablets. For MIC-determinations, 785 isolates and their disk diffusion results were collected. None of the 12 clinical isolates with non-beta-lactamase-mediated ampicillin resistance was detected as resistant in the participating laboratories. The ampicillin and cefaclor results of the isolates were no better even when a laboratory was able to separate the control strains. Cefaclor results were unreliable because of poor disk diffusion-MIC correspondence and incoherent breakpoint references. Interlaboratory variation of the zone diameters caused false intermediate results of cefuroxime-susceptible strains. When ampicillin, cefaclor and cefuroxime were tested, the discrimination of laboratories using disks and tablets was equal, whereas the laboratories using paper disks were better able to detect trimethoprim-sulfa resistance.

Improved WO3 photocatalytic efficiency using ZrO2 and Ru for the degradation of carbofuran and ampicillin.

PubMed

Gar Alalm, Mohamed; Ookawara, Shinichi; Fukushi, Daisuke; Sato, Akira; Tawfik, Ahmed

2016-01-25

The photocatalytic degradation of carbofuran (pesticide) and ampicillin (pharmaceutical) using synthesized WO3/ZrO2 nanoparticles under simulated solar light was investigated. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectra analyses were used to characterize the prepared catalysts. The optimum ratio of WO3 to ZrO2 was determined to be 1:1 for the degradation of both contaminants. The degradation of carbofuran and ampicillin by WO3/ZrO2 after 240 min of irradiation was 100% and 96%, respectively. Ruthenium (Ru) was employed as an additive to WO3/ZrO2 to enhance the photocatalytic degradation rate. Ru/WO3/ZrO2 exhibited faster degradation rates than WO3/ZrO2. Furthermore, 100% and 97% degradation of carbofuran and ampicillin, respectively, was achieved using Ru/WO3/ZrO2 after 180 min of irradiation. The durability of the catalyst was investigated by reusing the same suspended catalyst, which achieved 92% of its initial efficiency. The photocatalytic degradation of ampicillin and carbofuran followed pseudo-first order kinetics according to the Langmuir-Hinshelwood model. Copyright © 2015 Elsevier B.V. All rights reserved.

Paradox between the responses of Escherichia coli K1 to ampicillin and chloramphenicol in vitro and in vivo.

PubMed

Kim, K S; Manocchio, M; Anthony, B F

1984-11-01

We evaluated the activity of ampicillin and chloramphenicol in vitro and in vivo against an Escherichia coli K1 strain. In vitro, the strain was relatively susceptible to both antibiotics (MIC and MBC of ampicillin, 2 and 4 micrograms/ml; MIC and MBC of chloramphenicol, 4 and 64 micrograms/ml). Checkerboard determinations of MBCs of drug combinations were consistent with antibiotic antagonism. Killing curves with concentrations of antibiotics similar to in vivo levels in blood and cerebrospinal fluid of infected rats indicated antagonism within the first 4 h and an indifferent effect of the combination at 24 h. Paradoxically, the combination was significantly more effective than ampicillin or chloramphenicol alone in vivo in infant rats. This was shown by (i) more rapid bacterial clearance from the blood and cerebrospinal fluid, (ii) a decreased incidence of meningitis in bacteremic animals, and (iii) improved survival. These findings illustrate a divergence between the effects of ampicillin and chloramphenicol against E. coli in vitro and in vivo and suggest that this combination is an effective synergistic regimen in this experimental model of E. coli bacteremia and meningitis.

Evaluation of Enterococcus faecalis clinical isolates with 'penicillin-resistant, ampicillin-susceptible' phenotype as reported by Vitek-2 Compact system.

PubMed

Tan, Yen Ee; Ng, Lily S Y; Tan, Thean Yen

2014-10-01

It has been recently reported that ampicillin susceptibility cannot accurately predict piperacillin and imipenem susceptibilities in penicillin-resistant, ampicillin-susceptible (Pen-R, Amp-S) Enterococcus faecalis isolates, contrary to the current Clinical and Laboratory Standards Institute (CLSI) recommendations. This has important therapeutic implications. Such isolates were noted after the use of Vitek-2 Compact system AST-GP67 susceptibility cards in a Singapore general hospital and they were increasing in numbers. The primary aim of this study was to evaluate these clinical isolates against microbroth dilution (MBD) technique and other commonly used antimicrobial susceptibility test (AST) methods for penicillin and ampicillin. The secondary aim was to evaluate whether ampicillin susceptibility could indeed be a reliable surrogate marker for piperacillin and imipenem susceptibilities in E. faecalis isolates that were confirmed Pen-R, Amp-S.From 2009 to 2013, a total of 49 isolates (5%) of 983 non-duplicate E. faecalis tested by Vitek-2 displayed the 'Pen-R, Amp-S' phenotype in a general hospital in Singapore. These were tested against MBD which was the reference method, Etest and disc diffusion for penicillin and ampicillin. Susceptibilities to piperacillin and imipenem were also tested using MBD. In addition, β-lactamase production test was performed. Forty E. faecalis isolates with penicillin-susceptible, ampicillin-susceptible (Pen-S, Amp-S) phenotype were included for comparative purposes.The categorical agreement rate was 100% for all AST methods in ampicillin reporting for the 'Pen-R, Amp-S' group of E. faecalis isolates. However, a large number of isolates (46 isolates, 93.9%) fell into the major error category for penicillin testing by the Vitek-2 system. Penicillin minimum inhibitory concentrations (MICs) generated by the Vitek-2 system for the majority of these isolates were two doubling dilutions higher compared to those obtained by the reference test. The Etest method correlated well with the MBD method. Thirty-two isolates (65.3%) were in categorical agreement with the MBD method when tested by the disc diffusion method for penicillin. Only three E. faecalis isolates (6.1%) were confirmed to have the uncommon penicillin resistance phenotype, with two of them showing resistance to piperacillin and intermediate to imipenem. β-lactamase production test was negative for all isolates. Among the Pen-S, Amp-S E. faecalis isolates, the categorical agreement was 100% for penicillin and ampicillin in all the tested methods.Enterococcus faecalis with 'Pen-R, Amp-S' phenotype reported by the Vitek-2 system using AST-GP67 susceptibility cards must be confirmed with a reference test, the Etest method being a good alternative. The Vitek-2 system generated higher penicillin MIC readings compared to MBD in this study. The actual prevalence of this uncommon penicillin resistance phenotype in E. faecalis was found to be low in this institution. More studies are required to confirm the reliability of ampicillin as a surrogate marker for piperacillin and imipenem susceptibilities in these isolates.

Antimicrobial prophylaxis for major head and neck surgery in cancer patients: sulbactam-ampicillin versus clindamycin-amikacin.

PubMed

Phan, M; Van der Auwera, P; Andry, G; Aoun, M; Chantrain, G; Deraemaecker, R; Dor, P; Daneau, D; Ewalenko, P; Meunier, F

1992-09-01

A total of 99 patients with head and neck cancer who were to undergo surgery were randomized in a prospective comparative study of sulbactam-ampicillin (1:2 ratio; four doses of 3 g of ampicillin and 1.5 g of sulbactam intravenously [i.v.] every 6 h) versus clindamycin (four doses of 600 mg i.v. every 6 h)-amikacin (two doses of 500 mg i.v. every 12 h) as prophylaxis starting at the induction of anesthesia. The two groups of evaluable patients (43 in the clindamycin-amikacin treatment group and 42 in the sulbactam-ampicillin treatment group) were comparable as far as age (mean, 57 years; range, 21 to 84 years), sex ratio (71 males, 28 females), weight (mean, 66 kg; range, 40 to 69 kg), indication for surgery (first surgery, 48 patients; recurrence, 37 patients), previous anticancer treatment (surgery, radiation therapy, chemotherapy), type of surgery, and stage of cancer. The overall infection rate (wound, bacteremia, and bronchopneumonia) within 20 days after surgery was 20 patients in each group. Wound infections occurred in 14 (33%) sulbactam-ampicillin-treated patients and 9 (21%) clindamycin-amikacin-treated patients (P = 0.19; not significant). The rates of bacteremia were 2 and 4%, respectively. The rates of bronchopneumonia were 14.3 and 23.2%, respectively (P was not significant). Most infections were polymicrobial, but strict anaerobes were recovered only from patients who received sulbactam-ampicillin. Antimicrobial treatment was required within 20 days after surgery for 42% of the sulbactam-ampicillin-treated patients and 44% of the clindamycin-amikacin-treated patients. By comparison with previous studies, we observed a decreased efficacy of antimicrobial prophylaxis in patients with head and neck cancer undergoing surgery because of the increased proportion of patients who were at very high risk for infection (extensive excision and plastic reconstruction in patients with recurrent stage III and IV cancers) and because of the longer duration of surgery.

Antimicrobial prophylaxis for major head and neck surgery in cancer patients: sulbactam-ampicillin versus clindamycin-amikacin.

PubMed Central

Phan, M; Van der Auwera, P; Andry, G; Aoun, M; Chantrain, G; Deraemaecker, R; Dor, P; Daneau, D; Ewalenko, P; Meunier, F

1992-01-01

A total of 99 patients with head and neck cancer who were to undergo surgery were randomized in a prospective comparative study of sulbactam-ampicillin (1:2 ratio; four doses of 3 g of ampicillin and 1.5 g of sulbactam intravenously [i.v.] every 6 h) versus clindamycin (four doses of 600 mg i.v. every 6 h)-amikacin (two doses of 500 mg i.v. every 12 h) as prophylaxis starting at the induction of anesthesia. The two groups of evaluable patients (43 in the clindamycin-amikacin treatment group and 42 in the sulbactam-ampicillin treatment group) were comparable as far as age (mean, 57 years; range, 21 to 84 years), sex ratio (71 males, 28 females), weight (mean, 66 kg; range, 40 to 69 kg), indication for surgery (first surgery, 48 patients; recurrence, 37 patients), previous anticancer treatment (surgery, radiation therapy, chemotherapy), type of surgery, and stage of cancer. The overall infection rate (wound, bacteremia, and bronchopneumonia) within 20 days after surgery was 20 patients in each group. Wound infections occurred in 14 (33%) sulbactam-ampicillin-treated patients and 9 (21%) clindamycin-amikacin-treated patients (P = 0.19; not significant). The rates of bacteremia were 2 and 4%, respectively. The rates of bronchopneumonia were 14.3 and 23.2%, respectively (P was not significant). Most infections were polymicrobial, but strict anaerobes were recovered only from patients who received sulbactam-ampicillin. Antimicrobial treatment was required within 20 days after surgery for 42% of the sulbactam-ampicillin-treated patients and 44% of the clindamycin-amikacin-treated patients. By comparison with previous studies, we observed a decreased efficacy of antimicrobial prophylaxis in patients with head and neck cancer undergoing surgery because of the increased proportion of patients who were at very high risk for infection (extensive excision and plastic reconstruction in patients with recurrent stage III and IV cancers) and because of the longer duration of surgery. PMID:1416895

[Sensitivity of clinical Proteus strains to antibiotics and their combinations].

PubMed

Sheina, E P; Arutcheva, A A

1978-05-01

In 1976 isolation of Proteus from wounds of patients with various purulent processes amounted to 14.5 per cent. Serotypes 0-10, 0-3 and H-3 predominated among the isolates. Sensitivity of 35 clinical strains of Proteus to 10 antibiotics, furagin and nevigramone was studied by the method of serial dilutions in liquid media. All the isolates were highly resistant to the antibiotics except gentamicin, furagin and nevigramone, the MIC of which for most of the strains was 3.12, 1.6-3.12 and 6.25-12.5 gamma/ml, respectively. The effect of 14 combinations of chemotherapeutics was also studied. The combinations of gentamicin with carbenicillin, gentamicin with ampicillin and monomycin with ampicillin proved to be most effective against the Proteus strains tested. The following combinations may be of practical value: monomycin + carbenicillin, kanamycin + ampicillin, kanamycin + carbenicillin, ampicillin + furagin, gentamicin + nevigramone. The combinations of carbenicillin with furagin and gentamicin with furagin were also rational.

Comparative Susceptibility of Haemophilus Species to Cefaclor, Cefamandole, and Five Other Cephalosporins and Ampicillin, Chloramphenicol, and Tetracycline

PubMed Central

Watanakunakorn, Chatrchai; Glotzbecker, Cheryl

1979-01-01

The minimal inhibitory concentration of cefaclor, cephalexin, cephradine, cefamandole, cephalothin, cephapirin, cefazolin, ampicillin, chloramphenicol, and tetracycline for inhibition of 198 freshly isolated clinical strains of Haemophilus species (23 H. influenzae type b, 157 H. influenzae non-type b, 14 H. parainfluenzae, and 4 H. aphrophilus) was determined simultaneously by a slightly modified WHO-ICS agar dilution method. Nine strains were resistant to ampicillin. There was no correlation between ampicillin resistance and minimal inhibitory concentration of other antibiotics. All strains were susceptible to chloramphenicol, and all except five were susceptible to tetracycline. Cefaclor was the most active oral cephalosporin, and cefamandole was the most active parenteral cephalosporin. Among the seven cephalosporins tested, cefamandole was the most effective compound. All but two strains were inhibited by cefamandole at 2 μg or less per ml. PMID:258112

Population dynamics of transgenic strain Escherichia coli Z905/pPHL7 in freshwater and saline lake water microcosms with differing microbial community structures

NASA Astrophysics Data System (ADS)

Popova, L. Yu.; Kargatova, T. V.; Ganusova, E. E.; Lobova, T. I.; Boyandin, A. N.; Mogilnaya, O. A.; Pechurkin, N. S.

Populations of Escherichia coli Z905/pPHL7, a transgenic microorganism, were heterogenic in the expression of plasmid genes when adapting to the conditions of water microcosms of various mineralization levels and structure of microbial community. This TM has formed two subpopulations (ampicillin-resistant and ampicillin-sensitive) in every microcosm. Irrespective of mineralization level of a microcosm, when E. coli Z905/pPHL7 alone was introduced, the ampicillin-resistant subpopulation prevailed, while introduction of the TM together with indigenous bacteria led to the dominance of the ampicillin-sensitive subpopulation. A high level of lux gene expression maintained longer in the freshwater microcosms than in sterile saline lake water microcosms. A horizontal gene transfer has been revealed between the jointly introduced TM and Micrococcus sp. 9/pSH1 in microcosms with the Lake Shira sterile water.

Depletion of long-acting ampicillin in goat milk following intramuscular administration.

PubMed

Ferrini, Anna Maria; Trenta, Simona; Mannoni, Veruscka; Rosati, Remo; Coni, Ettore

2010-12-08

Although goat milk production represents today a very small percentage of the world milk market, this percentage has been growing continuously during the past 20 years. Goat milk is the basic milk supply in many developing countries and provides tasteful derivative products in developed countries. Goats, as well as all milk-producing animals, can be affected by mastitis, but goats being considered a minor species, few drugs are specifically registered for these animals; most, at least for mastitis treatment, are usually tested and registered for use in cows. This situation leads often to the adoption for goat milk of withdrawal periods defined for cows even if these extrapolations prove almost never valid for goats. In the present study, the elimination of the β-lactam antibacterial agent ampicillin in goat milk was investigated. Ampicillin was chosen because it is one of the most common antibiotics used by goat farmers against mastitis due to the fact that it is well tolerated and has short elimination times in cows. Goats were treated with long-acting ampicillin at 15 mg (kg of body weight)(-1) by double intramuscular injection at 72 h interval. Milk was collected in a 12 h milking scheme. The method used to determine the levels of ampicillin in goat milk was based on a liquid-liquid extraction of this drug from the matrix, successive derivatization with formaldehyde, and final separation by HPLC with fluorescence detection. The results point out a slow depletion of ampicillin and, consequently, a withdrawal period (13 milkings) longer than that extrapolated and authorized for cows and sheep.

Genetic Transformation of Bacteria.

ERIC Educational Resources Information Center

Moss, Robert.

1991-01-01

An activity in which students transform an ampicillin-sensitive strain of E. coli with a plasmid containing a gene for ampicillin resistance is described. The procedure for the preparation of competent cells and the transformation of competent E. coli is provided. (KR)

Acute Toxicological Study of Ampicillin Anhydrate Microcapsules in Sprague-Dawley Rats.

DTIC Science & Technology

This document contains the results of an acute toxicological study to determine the toxicologic potential of ampicillin anhydrate microcapsules on...various organs of the rat. Keywords: Wound treatment; Antibiotic microcapsule ; Controlled release; Experimental data; Tables data. (aw)

[Bactericidal activity of serum and chemotherapy in sensitive and resistant exciter (author's transl)].

PubMed

Eyer, H; Metz, H; Preac-Mursic, V

1975-11-21

Comparing examinations with Ampicillin sensitive and resistant bacteria-strains show that the bactericidal activity of serum is dependent on the bacteria-strains, on the Ampicillin sensitivity of the particular exciter and on the number of bacteria/ml (germ count). Bactericide effect could always be obtained with sensitive strains as a result of additional chemotherapy. With several resistant strains a bactericide effect could not be obtained in this case the continuous optimal Ampicillin addition was the decisive factor. Because of the extremely complicated process of the bactericide one should not make general conclusions from the individual experimental results.

Prophylactic ampicillin versus cefazolin for the prevention of post-cesarean infectious morbidity in Rwanda.

PubMed

Mivumbi, Victor N; Little, Sarah E; Rulisa, Stephen; Greenberg, James A

2014-03-01

To evaluate the efficacy of ampicillin versus cefazolin as prophylactic antibiotics prior to cesarean delivery in Rwanda. In a prospective, randomized, open-label, single-site study conducted between March and May 2012, the effects of prophylactic ampicillin versus cefazolin were compared among women undergoing cesarean delivery at the Centre Hospitalier Universitaire de Kigali, Rwanda. Postoperatively, participants were evaluated daily for infectious morbidity while in the hospital. Follow-up was done by phone and by appointment at the hospital within 2 weeks of delivery. During the study period, there were 578 total deliveries and 234 cesarean deliveries (40.4%). Overall, 132 women were enrolled in the study and randomized to receive either ampicillin (n=66) or cefazolin (n=66). No women were lost to follow-up. The overall infection rate was 15.9% (21/132). The infection rate in the ampicillin group and the cefazolin group was 25.8% (17/66) and 6.1% (4/66), respectively. Implementing a universal protocol in Rwanda of prophylactic cefazolin prior to cesarean delivery might reduce postoperative febrile morbidity, use of postoperative antibiotics, and number of postoperative days in hospital. Copyright © 2013 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Transformation products of amoxicillin and ampicillin after photolysis in aqueous matrices: Identification and kinetics.

PubMed

Arsand, Juliana Bazzan; Hoff, Rodrigo Barcellos; Jank, Louise; Meirelles, Lucas N; Silvia Díaz-Cruz, M; Pizzolato, Tânia Mara; Barceló, Damià

2018-06-18

Antibiotics are widely used in human medicine and veterinary production. Residues of these compounds reach the water sources through waste or direct application (e.g. aquaculture). The constant input of the parent drugs and their transformation products into the environment leads these pharmaceuticals to be considered as emerging pollutants. For some molecules, the pathway of degradation and formation in products is less known. To assess the impact of these substances in the environment and in the human health, it is necessary to elucidate the transformation products and their kinetic of degradation to evaluate the possible risks. In the present report, the characterization and the degradation kinetic of two widely used β-lactams antibiotics - amoxicillin and ampicillin - was evaluated. Surface water samples containing these antibiotics were submitted to photolysis and analyzed by liquid chromatography coupled to mass spectrometry with Orbitrap detection in order to establish the profile of degradation and the formation of transformation products. Results showed that the degradation of amoxicillin and ampicillin is almost complete and reach their maximum at 48 h in river water. Moreover, a database containing >65 transformation products of amoxicillin and ampicillin was build and real samples of industrial wastewater were analyzed to investigate the occurrence of amoxicillin, ampicillin and their transformation products. Copyright © 2018. Published by Elsevier B.V.

Effects of ampicillin/sulbactam and enrofloxacin on the blood pressure of isoflurane anesthetized dogs.

PubMed

Moorer, Jeremiah D; Towle-Millard, Heather A; Gross, Marjorie E; Payton, Mark E

2013-01-01

A blinded, prospective, randomized crossover study was performed to determine the effects of ampicillin Na/sulbactam Na and enrofloxacin on the blood pressure (BP) of healthy anesthetized dogs. Eight dogs were anesthetized three different times. They randomly received enrofloxacin, ampicillin Na/sulbactam Na, and saline. Systolic, diastolic, and mean arterial BPs (SAP, DAP, and MAP, respectively), heart rate (HR), O2 saturation of hemoglobin, end-tidal CO2 (ETCO2) concentration, inspired isoflurane concentration, end-tidal isoflurane (ETiso) concentration, respiratory rate, electrocardiogram, and body temperature were measured for 20 min prior to administration of treatment, during administration over 30 min, and for 30 min after administration. There was no significant difference in the SAP or ETiso. There was no significant change in the arterial pressure values over time in the enrofloxacin and ampicillin Na/sulbactam Na groups. The control group's MAP increased over time and was increased compared with the enrofloxacin group at times 25, 35, 45, and 55. The statistical difference between the enrofloxacin and the control groups was due to an increase in the MAP in the control group, not a decrease in the enrofloxacin group's BP. Neither enrofloxacin nor ampicillin Na/sulbactam Na caused hypotension in healthy dogs anesthetized with isoflurane and fentanyl.

Antibiotic and Duration of Perioperative Prophylaxis Predicts Surgical Site Infection in Head and Neck Surgery.

PubMed

Langerman, Alexander; Thisted, Ronald; Hohmann, Samuel; Howell, Michael

2016-06-01

To examine the effect of giving antibiotics on the day of surgery (DOS) vs DOS and first postoperative day (DOS+1) for prophylaxis against surgical site infection (SSI) in clean-contaminated head and neck surgery (CCHNS). Retrospective multi-institution analysis using University HealthSystem Consortium data. A multivariate logistic regression model of 8836 discharge records from patients undergoing CCHNS was used to determine the odds of SSI for antibiotic agent/duration combinations. Ninety-two academic and affiliated medical centers from 2008 to 2011. Ampicillin/sulbactam, clindamycin, cefazolin + metronidazole, and cefazolin alone were the most common antibiotics. For patients receiving antibiotics only on DOS, there was no significant difference in odds of SSI based on antibiotic choice. When given on the DOS and DOS+1, patients receiving ampicillin/sulbactam had a reduction in odds of SSI by over two-thirds (odds ratio [OR], 0.28 [95% confidence interval, 0.13-0.61], P = .001, compared with ampicillin/sulbactam on DOS only), whereas this effect was not seen with clindamycin (1.82 [0.93-3.56], P = .078, compared with clindamycin on DOS only). Prolonging clindamycin beyond the DOS was associated with a higher odds of SSI compared with DOS-only ampicillin/sulbactam (OR, 2.66; 95% CI, 1.33-5.30; P = .006). These relationships held in a subset of physicians and hospitals that used multiple different regimens. DOS+1 regimens were not associated with an increased odds of antibiotic-induced complications. Prolonging ampicillin/sulbactam beyond the day of surgery may have a protective effect against SSI, and 1 or more days of ampicillin/sulbactam may be preferable to multiple days of clindamycin. New randomized trials are needed to define the ideal regimen for CCHNS. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Rhein 8-O-β-D-Glucopyranoside Elicited the Purgative Action of Daiokanzoto (Da-Huang-Gan-Cao-Tang), Despite Dysbiosis by Ampicillin.

PubMed

Takayama, Kento; Tabuchi, Norihiko; Fukunaga, Masahito; Okamura, Nobuyuki

2016-01-01

Sennoside A (SA), the main purgative constituent of Daiokanzoto (da-huang-gan-cao-tang; DKT), is generally regarded as a prodrug that is transformed into an active metabolite by β-glucosidase derived from Bifidobacterium spp. It has been suggested that antibiotics would promote dysbiosis, and thereby inhibit the purgative activity of DKT. In this study, ampicillin was administered to mice for 8 d, and the changes in the SA metabolism of SA alone and of DKT were investigated. The results showed that the SA metabolism of SA singly continued to be inhibited by ampicillin, but that of DKT was activated from day 3 under the same conditions. In order to investigate the mechanism of SA metabolism activated by DKT in the mice administered ampicillin, changes in the SA metabolism were observed in the presence of rhein 8-O-β-D-glucopyranoside (RG) in rhubarb and liquiritin in glycyrrhiza, both of which accelerated the SA metabolism. In fact, RG achieved an activation of SA metabolism similar to that by DKT. The purgative action of DKT, which was continued treatment of the ampicillin, was significantly greater than that by SA alone, and it was shown that RG was involved in this effect. We also analyzed changes in the intestinal microbiota before and after administration of ampicillin. No Bifidobacteria were detected throughout the treatment, but the population of Bacteroides was significantly increased after 3 d under the same conditions. Taken together, these results strongly suggested that the RG in DKT changed the function of Bacteroides and thereby allowed DKT to metabolize SA.

Serotypes, antimicrobial susceptibility, and beta-lactam resistance mechanisms of clinical Haemophilus influenzae isolates from Bulgaria in a pre-vaccination period.

PubMed

Setchanova, Lena Petrova; Kostyanev, Tomislav; Markovska, Rumyana; Miloshev, George; Mitov, Ivan Gergov

2013-02-01

To determine the serotypes, antimicrobial susceptibility, and beta-lactam resistance mechanisms of Haemophilus influenzae strains isolated from invasive and respiratory tract infections (RTIs) prior to the introduction of Haemophilus influenzae type b (Hib) vaccination in Bulgaria. A total of 259 isolates were serotyped by polymerase chain reaction. Susceptibility to antibiotics and beta-lactamase production were determined, and DNA sequencing of the ftsI gene was performed for ampicillin non-susceptible strains. The invasive H. influenzae infections in children were mainly due to serotype b (94.5% in meningitis and 88.9% in other invasive cases). Non-typeable strains (97.4%) were the most frequently found H. influenzae strains in RTIs both in children and adults. Non-susceptibility to ampicillin occurred in 22% of all strains. Ceftriaxone and levofloxacin were the most active agents tested. Ampicillin resistance occurred in 34.4% of invasive strains, and beta-lactamase production was the only mechanism found. Among respiratory tract isolates, ampicillin non-susceptible strains (18%) were classified into the following groups: beta-lactamase-positive, ampicillin-resistant (BLPAR) strains (7.2%); beta-lactamase-negative, ampicillin-non-susceptible (BLNAR) strains (8.2%); and beta- lactamase-positive, amoxicillin-clavulanate-resistant (BLPACR) strains (2.6%). Among 21 BLNAR and BLPACR strains there were 9 different patterns of multiple-amino acid substitutions in penicillin-binding protein 3. Of these, most isolates (81.0%) belonged to group II, defined by the Asn526Lys substitution. Beta-lactamase production was more common among invasive strains than in respiratory isolates. BLNAR and BLPACR H. influenzae were found only among respiratory tract isolates.

An animal source for the ROB-1 beta-lactamase of Haemophilus influenzae type b.

PubMed

Medeiros, A A; Levesque, R; Jacoby, G A

1986-02-01

The most common cause of ampicillin resistance in Haemophilus influenzae type b is production of TEM-1 beta-lactamase; however, a novel enzyme with a similar substrate profile but a quite different isoelectric point has also been described. This beta-lactamase, designated ROB-1, has not been found previously in any other organism. In a survey of 46 ampicillin-resistant H. influenzae type b isolates, we found a second human isolate that produces ROB-1 and discovered that ampicillin-resistant isolates of the porcine pathogen Haemophilus pleuropneumoniae also produced ROB-1. In both Haemophilus species ROB-1 production was determined by plasmids that had considerable DNA sequence homology. However, the ROB-1 and TEM-1 beta-lactamase genes were not related. Our findings suggest that this form of ampicillin resistance has an animal reservoir and that conditions fostering its prevalence in animal strains may play a role in the spread of resistance to human pathogens.

Plant Phenols as Antibiotic Boosters: In Vitro Interaction of Olive Leaf Phenols with Ampicillin.

PubMed

Lim, Anxy; Subhan, Nusrat; Jazayeri, Jalal A; John, George; Vanniasinkam, Thiru; Obied, Hassan K

2016-03-01

The antimicrobial properties of olive leaf extract (OLE) have been well recognized in the Mediterranean traditional medicine. Few studies have investigated the antimicrobial properties of OLE. In this preliminary study, commercial OLE and its major phenolic secondary metabolites were evaluated in vitro for their antimicrobial activities against Escherichia coli and Staphylococcus aureus, both individually and in combination with ampicillin. Besides luteolin 7-O-glucoside, OLE and its major phenolic secondary metabolites were effective against both bacteria, with more activity on S. aureus. In combination with ampicillin, OLE, caffeic acid, verbascoside and oleuropein showed additive effects. Synergistic interaction was observed between ampicillin and hydroxytyrosol. The phenolic composition of OLE and the stability of olive phenols in assay medium were also investigated. While OLE and its phenolic secondary metabolites may not be potent enough as stand-alone antimicrobials, their abilities to boost the activity of co-administered antibiotics constitute an imperative future research area. Copyright © 2016 John Wiley & Sons, Ltd.

Population dynamics of transgenic strain Escherichia coli Z905/pPHL7 in freshwater and saline lake water microcosms with differing microbial community structures

NASA Technical Reports Server (NTRS)

Popova, L. Yu; Kargatova, T. V.; Ganusova, E. E.; Lobova, T. I.; Boyandin, A. N.; Mogilnaya, O. A.; Pechurkin, N. S.

2005-01-01

Populations of Escherichia coli Z905/pPHL7, a transgenic microorganism, were heterogenic in the expression of plasmid genes when adapting to the conditions of water microcosms of various mineralization levels and structure of microbial community. This TM has formed two subpopulations (ampicillin-resistant and ampicillin-sensitive) in every microcosm. Irrespective of mineralization level of a microcosm, when E. coli Z905/pPHL7 alone was introduced, the ampicillin-resistant subpopulation prevailed, while introduction of the TM together with indigenous bacteria led to the dominance of the ampicillin-sensitive subpopulation. A high level of lux gene expression maintained longer in the freshwater microcosms than in sterile saline lake water microcosms. A horizontal gene transfer has been revealed between the jointly introduced TM and Micrococcus sp. 9/pSH1 in microcosms with the Lake Shira sterile water. c2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

Activity of semisynthetic penicillins and synergism with mecillinam against Bacteroides species.

PubMed Central

Trestman, I; Kaye, D; Levison, M E

1979-01-01

The minimal inhibitory concentrations (MIC) of six penicillins (ampicillin, carbenicillin, ticarcillin, piperacillin, mezlocillin, and Bay k 4999) against 29 clinical isolates of Bacteriodes spp. (including Bacteroides fragilis, Bacteroides thetaiotaomicron, and Bacteroides vulgatus) were determined by an agar dilution method. Bay k 4999 was most active, followed in descending order by ampicillin, piperacillin, mezlocillin, ticarcillin, and carbenicillin. Mecillinam, a 6 beta-amidino-penicillanic acid, inhibited no strains at 50 micrograms/ml, but when compared with ampicillin, a fourfold or greater increase in MIC for ampicillin (antagonism) was noted in 3 of 29 strains, with no effect on MIC for 26 strains, whereas when combined with carbenicillin, a fourfold or greater decrease in MIC for both antibiotics (synergism) was noted in 12 strains, 4 of which had an MIC of greater than or equal to 250 micrograms/ml for carbenicillin alone. These studies demonstrate the increased activity of some newer semisynthetic penicillins and the potential synergy obtained with mecillinam and carbenicillin against Bacteroides sp. PMID:228593

Reevaluation of interpretive criteria for Haemophilus influenzae by using meropenem (10-microgram), imipenem (10-microgram), and ampicillin (2- and 10-microgram) disks.

PubMed Central

Zerva, L; Biedenbach, D J; Jones, R N

1996-01-01

A collection of 300 Haemophilus influenzae clinical strains was used to assess in vitro susceptibility to carbapenems (meropenem, imipenem) by MIC and disk diffusion methods and to compare disk diffusion test results with two potencies of ampicillin disks (2 and 10 micrograms). The isolates included ampicillin-susceptible or- intermediate (167 strains), beta-lactamase-positive (117 strains), and beta-lactamase-negative ampicillin-resistant (BLNAR; 16 strains) organisms. Disk diffusion testing was performed with 10-micrograms meropenem disks from two manufacturers. Meropenem was highly active against H. influenzae strains (MIC50, 0.06 microgram/ml; MIC90, 0.25 microgram/ml; MIC50 and MIC90, MICs at which 50 and 90%, respectively, of strains are inhibited) and was 8- to 16-fold more potent than imipenem (MIC50, 1 microgram/ml; MIC90, 2 micrograms/ml). Five non-imipenem-susceptible strains were identified (MIC, 8 micrograms/ml), but the disk diffusion test indicated susceptibility (zone diameters, 18 to 21 mm). MIC values of meropenem, doxycycline, ceftazidime, and ceftriaxone for BLNAR strains were two- to fourfold greater than those for other strains. The performance of both meropenem disks was comparable and considered acceptable. A single susceptible interpretive zone diameter of > or = 17 mm (MIC, < = or 4 micrograms/ml) was proposed for meropenem. Testing with the 2-micrograms ampicillin disk was preferred because of an excellent correlation between MIC values and zone diameters (r = 0.94) and superior interpretive accuracy with the susceptible criteria at > or = 17 mm (MIC, < or = 1 microgram/ml) and the resistant criteria at < or = 13 mm (MIC, > or = 4 micrograms/ml). Among the BLNAR strains tested, 81.3% were miscategorized as susceptible or intermediate when the 10-micrograms ampicillin disk was used, while the 2-micrograms disk produced only minor interpretive errors (12.5%). Use of these criteria for testing H. influenzae against meropenem and ampicillin should maximize reference test and standardized disk diffusion test performance with the Haemophilus Test Medium. The imipenem disk diffusion test appears compromised and should be used with caution for detecting strains for which imipenem MICs are elevated. PMID:8818892

21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

Code of Federal Regulations, 2012 CFR

2012-04-01

... daily, for up to 3 days. For pneumonia: 3 milligrams per pound of body weight, intramuscularly, twice... coli and bacterial pneumonia caused by Pasteurella spp. susceptible to ampicillin. (C) Limitations. Not.... Treatment of bacterial enteritis (colibacillosis) caused by E. coli and bacterial pneumonia caused by...

21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

Code of Federal Regulations, 2013 CFR

2013-04-01

... daily, for up to 3 days. For pneumonia: 3 milligrams per pound of body weight, intramuscularly, twice... coli and bacterial pneumonia caused by Pasteurella spp. susceptible to ampicillin. (C) Limitations. Not.... Treatment of bacterial enteritis (colibacillosis) caused by E. coli and bacterial pneumonia caused by...

21 CFR 522.90a - Ampicillin trihydrate suspension.

Code of Federal Regulations, 2014 CFR

2014-04-01

... days. For pneumonia: 3 mg per pound of body weight, intramuscularly, twice daily, for up to 3 days. (ii... pneumonia caused by Pasteurella spp. susceptible to ampicillin. (iii) Limitations. Treated animals must not... for use. Treatment of bacterial enteritis (colibacillosis) caused by E. coli and bacterial pneumonia...

21 CFR 520.90b - Ampicillin trihydrate tablets.

Code of Federal Regulations, 2013 CFR

2013-04-01

....90b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90b Ampicillin... 5 days, stop treatment, reevaluate diagnosis, and change therapy. (2) Indications for use. Oral...

21 CFR 520.90b - Ampicillin trihydrate tablets.

Code of Federal Regulations, 2014 CFR

2014-04-01

....90b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90b Ampicillin... 5 days, stop treatment, reevaluate diagnosis, and change therapy. (2) Indications for use. Oral...

21 CFR 556.40 - Ampicillin.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.40 Ampicillin. A tolerance of 0.01 p/m is established for negligible...

21 CFR 556.40 - Ampicillin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.40 Ampicillin. A tolerance of 0.01 p/m is established for negligible...

21 CFR 556.40 - Ampicillin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.40 Ampicillin. A tolerance of 0.01 p/m is established for negligible...

21 CFR 556.40 - Ampicillin.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.40 Ampicillin. A tolerance of 0.01 p/m is established for negligible...

21 CFR 556.40 - Ampicillin.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.40 Ampicillin. A tolerance of 0.01 p/m is established for negligible...

Ampicillin resistance of invasive Haemophilus influenzae isolates in Germany 2009-2012.

PubMed

Lâm, Thiên-Trí; Claus, Heike; Elias, Johannes; Frosch, Matthias; Vogel, Ulrich

2015-10-01

In this retrospective study covering a four-year observation period (2009-2012) the prevalence of aminopenicillin resistance of invasive Haemophilus influenzae (Hi) in Germany was analyzed. The main resistance mechanism against aminopenicillins is conferred by β-lactamase production, which can be inhibited by clavulanate or sulbactam. Apart from that, β-lactamase negative ampicillin resistance (BLNAR) has been reported due to mutations in the penicillin-binding protein PBP3. The prevalence of BLNAR varies considerably in different countries. Representative data from Germany have not been reported. We analyzed 704 culture positive cases with bacteraemia or detection of Hi in cerebrospinal fluid; 82 isolates (11.6%) were phenotypically resistant to ampicillin. Among these isolates, 65 (79.3%) showed β-lactamase production, and 17 isolates (20.7%) were phenotypic BLNAR Hi. The proportion of ampicillin resistant isolates remained stable over the observation period. Analysis of the PBP3 sequences of 133 isolates with different susceptibility phenotypes including susceptible, BLNAR, and β-lactamase positive isolates, revealed a high genetic diversity. Previously described PBP3 mutations were associated to elevated MIC values, albeit not exclusively, since few highly susceptible strains were found to be positive for the mutations. Furthermore, since ampicillin susceptible strains with elevated MIC values frequently harboured these mutations, prediction of the resistance phenotype using ftsI sequencing appears to be impossible. Copyright © 2015 Elsevier GmbH. All rights reserved.

21 CFR 520.90f - Ampicillin trihydrate boluses.

Code of Federal Regulations, 2014 CFR

2014-04-01

....90f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90f Ampicillin... daily for up to 5 days. (i) Indications for use. Oral treatment of colibacillosis caused by Escherichia...

21 CFR 520.90e - Ampicillin trihydrate soluble powder.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Section 520.90e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90e Ampicillin...) Indications for use. Oral treatment of porcine colibacillosis (Escherichia coli) and salmonellosis (Salmonella...

21 CFR 520.90e - Ampicillin trihydrate soluble powder.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Section 520.90e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90e Ampicillin...) Indications for use. Oral treatment of porcine colibacillosis (Escherichia coli) and salmonellosis (Salmonella...

21 CFR 520.90f - Ampicillin trihydrate boluses.

Code of Federal Regulations, 2013 CFR

2013-04-01

....90f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90f Ampicillin... daily for up to 5 days. (i) Indications for use. Oral treatment of colibacillosis caused by Escherichia...

21 CFR 520.90e - Ampicillin trihydrate soluble powder.

Code of Federal Regulations, 2010 CFR

2010-04-01

... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90e Ampicillin...) Indications for use. Oral treatment of porcine colibacillosis (Escherichia coli) and salmonellosis (Salmonella... in swine only. Not for use in other animals which are raised for food production. Treated swine must...

21 CFR 522.90b - Ampicillin trihydrate powder for injection.

Code of Federal Regulations, 2014 CFR

2014-04-01

....90b Section 522.90b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.90b Ampicillin trihydrate powder for injection. (a) Specifications. Each milliliter of...

13C and 15N—Chemical Shift Anisotropy of Ampicillin and Penicillin-V Studied by 2D-PASS and CP/MAS NMR

NASA Astrophysics Data System (ADS)

Antzutkin, Oleg N.; Lee, Young K.; Levitt, Malcolm H.

1998-11-01

The principal values of the chemical shift tensors of all13C and15N sites in two antibiotics, ampicillin and penicillin-V, were determined by 2-dimensionalphaseadjustedspinningsideband (2D-PASS) and conventional CP/MAS experiments. The13C and15N chemical shift anisotropies (CSA), and their confidence limits, were evaluated using a Mathematica program. The CSA values suggest a revised assignment of the 2-methyl13C sites in the case of ampicillin. We speculate on a relationship between the chemical shift principal values of many of the13C and15N sites and the β-lactam ring conformation.

Meningitis due to ampicillin-and chloramphenicol-resistant Haemophilus influenzae type b in Canada. Case report and review

PubMed Central

Kabani, Amin; Joffe, Ari; Cadrain, Gisele; Jadavji, Taj

1990-01-01

The first report of a case of ampicillin- and chloramphenicol-resistant Haemophilus influenzae type b invasive infection in Canada is described in a four-month-old male with meningitis. He was treated with cefotaxime 200 mg/kg/day divided every 6 h and dexamethasone 0.6 mg/kg/day divided every 6 h, eventually recovering after a complicated course. Follow-up at 21 months showed mild to moderate global developmental delay. While chloramphenicol resistance is rare in North America, a case of meningitis initially unresponsive to ampicillin and chloramphenicol must be considered suspect for resistance. Third generation cephalosporins should be used for resistant cases. PMID:22553448

21 CFR 522.90b - Ampicillin trihydrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... subcutaneous or intramuscular injection. (ii) Indications for use. For treatment of strains of organisms...—(i) Amount. 2 to 5 mg/lb of body weight once daily by intramuscular injection. (ii) Indications for... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ampicillin trihydrate. 522.90b Section 522.90b...

Lactobacillus fermentum NS9 restores the antibiotic induced physiological and psychological abnormalities in rats.

PubMed

Wang, T; Hu, X; Liang, S; Li, W; Wu, X; Wang, L; Jin, F

2015-01-01

Gut microbiota play a vital role in maintaining the health of the host. Many factors affect gut microbiota; application of broad range antibiotics disturb microbiota, while probiotic application protects the microbiota. To investigate how probiotics alter the physiological and psychological changes induced by antibiotics, we tested the performance of ampicillin-treated rats in the presence or absence of Lactobacillus fermentum strain NS9, in elevated plus maze and Morris water maze. The results showed that NS9 normalised the composition of gut microbiota and alleviated the ampicillin-induced inflammation in the colon. The levels of the mineralocorticoid and N-methyl-D-aspartate receptors were also elevated in the hippocampus of the ampillicin+NS9 treated group. NS9 administration also reduced the anxiety-like behaviour and alleviated the ampicillin-induced impairment in memory retention. These findings suggest that NS9 is beneficial to the host, because it restores the physiological and psychological abnormalities induced by ampicillin. Our results highlight how gut contents regulate the brain, and shed light on the clinical applications of probiotics to treat the side effect of antibiotics and mental disorders.

Structure reactivity and thermodynamic analysis on the oxidation of ampicillin drug by copper(III) complex in aqueous alkaline medium (stopped-flow technique)

NASA Astrophysics Data System (ADS)

Shetti, Nagaraj P.; Hegde, Rajesh N.; Nandibewoor, Sharanappa T.

2009-07-01

Oxidation of penicillin derivative, ampicillin (AMP) by diperiodatocuprate(III) (DPC) in alkaline medium at a constant ionic strength of 0.01-mol dm -3 was studied spectrophotometrically. The reaction between DPC and ampicillin in alkaline medium exhibits 1:4 stoichiometry (ampicillin:DPC). Intervention of free radicals was observed in the reaction. Based on the observed orders and experimental evidences, a mechanism involving the protonated form of DPC as the reactive oxidant species has been proposed. The oxidation reaction in alkaline medium has been shown to proceed via a DPC-AMP complex, which decomposes slowly in a rate determining step to yield phenyl glycine (PG) and free radical species of 6-aminopenicillanic acid (6-APA), followed by other fast steps to give the products. The two major products were characterized by IR, NMR, LC-MS and Spot test. The reaction constants involved in the different steps of the mechanism were calculated. The activation parameters with respect to slow step of the mechanism were computed and discussed and thermodynamic quantities were also determined.

Comparative In Vitro Activity of Azlocillin, Ampicillin, Mezlocillin, Piperacillin, and Ticarcillin, Alone and in Combination with an Aminoglycoside

PubMed Central

White, G. Wesley; Malow, James B.; Zimelis, Victoria M.; Pahlavanzadeh, Hossein; Panwalker, Anand P.; Jackson, George Gee

1979-01-01

The in vitro activities of the newer semisynthetic penicillins azlocillin, mezlocillin, and piperacillin were compared with those of ampicillin and ticarcillin by using 290 clinical laboratory isolates. Piperacillin and mezlocillin were the most active against Escherichia coli, Proteus mirabilis, Klebsiella spp., and Enterobacter spp. When Pseudomonas aeruginosa was tested, piperacillin and azlocillin were more active than either mezlocillin or ticarcillin. Streptococcus pneumoniae and Haemophilus influenzae species were highly susceptible to all of the penicillins tested. Ticarcillin had relatively poor activity against enterococci. The rate of bacterial killing with multiples of the minimal inhibitory concentration of azlocillin, ampicillin, or ticarcillin was tested for E. coli, P. mirabilis, P. aeruginosa, and Klebsiella spp. Increasing concentrations increased the bactericidal effect. The effect of combining azlocillin, ampicillin, or ticarcillin with an aminoglycoside was studied by using both killing curves and checkerboards. The isobolograms constructed from the checkerboards showed a synergistic pattern for the organisms tested, which included E. coli, P. aeruginosa, Klebsiella spp., P. mirabilis, and enterococci. However, the rate of killing was increased by the combination only for P. aeruginosa and enterococci. PMID:111616

Short-term stability studies of ampicillin and cephalexin in aqueous solution and human plasma: Application of least squares method in Arrhenius equation.

PubMed

do Nascimento, Ticiano Gomes; de Jesus Oliveira, Eduardo; Basílio Júnior, Irinaldo Diniz; de Araújo-Júnior, João Xavier; Macêdo, Rui Oliveira

2013-01-25

A limited number of studies with application of the Arrhenius equation have been reported to drugs and biopharmaceuticals in biological fluids at frozen temperatures. This paper describes stability studies of ampicillin and cephalexin in aqueous solution and human plasma applying the Arrhenius law for determination of adequate temperature and time of storage of these drugs using appropriate statistical analysis. Stability studies of the beta-lactams in human plasma were conducted at temperatures of 20°C, 2°C, -20°C and also during four cycles of freeze-thawing. Chromatographic separation was achieved using a Shimpak C(18) column, acetonitrile as organic modifier and detection at 215nm. LC-UV-MS/MS was used to demonstrate the conversion of ampicillin into two diastereomeric forms of ampicilloic acid. Stability studies demonstrated degradation greater than 10% for ampicillin in human plasma at 20°C, 2°C and -20°C after 15h, 2.7days, 11days and for cephalexin at the same temperatures after 14h, 3.4days and 19days, respectively, and after the fourth cycle of freezing-thawing. The Arrhenius plot showed good prediction for the ideal temperature and time of storage for ampicillin (52days) and cephalexin (151days) at a temperature of -40°C, but statistical analysis (least squares method) must be applied to avoid incorrect extrapolations and estimated values out uncertainty limits. Copyright © 2012 Elsevier B.V. All rights reserved.

Immunological effects of reduced mucosal integrity in the early life of BALB/c mice.

PubMed

Bendtsen, Katja Maria; Hansen, Camilla Hartmann Friis; Krych, Łukasz; Skovgaard, Kerstin; Kot, Witold; Vogensen, Finn Kvist; Hansen, Axel Kornerup

2017-01-01

Certain stimuli at the gut barrier may be necessary in early life to establish a proper balance of immune tolerance. We evaluated a compromised barrier in juvenile mice in relation to microbiota and local and systemic immunity. BALB/c mice were treated with a low dose of dextran sulfate sodium (DSS) with or without ampicillin and lipopolysaccharide (LPS) to clarify the importance of microbial antigens and interaction between microbial-associated patterns and toll-like receptors. The barrier breach resulted in increased plasma LPS, which was highest in mice treated simultaneously with ampicillin. Adding LPS in the food reduced its levels in plasma. Regulatory T cells were acutely increased in mesenteric lymph nodes (MLN) and spleen during DSS treatment regardless of simultaneous ampicillin treatment. In contrast, NK T and NK cells decreased in MLN and in spleen. This acute DSS effect was reflected in fold changes of haptoglobin and Il1a in colon, and this was also more pronounced in mice simultaneously treated with ampicillin. On day 1 post-treatment, major upregulations of Ifng, Foxp3, Il1b, Il2, and Il6 genes in colon were only observed in the mice simultaneously treated with ampicillin. A two-fold upregulation of colonic Foxp3 and Il1a was evident 25 days post-treatment. DSS skewed the microbiota in favor of Gram negative phyla. Therefore, increased permeability induced tolerogenic immunity independent of microbiota, and this was enhanced by LPS stimulation.

Evaluation of polymorphisms in pbp4 gene and genetic diversity in penicillin-resistant, ampicillin-susceptible Enterococcus faecalis from hospitals in different states in Brazil.

PubMed

Infante, Victor Hugo Pacagnelli; Conceição, Natália; de Oliveira, Adriana Gonçalves; Darini, Ana Lúcia da Costa

2016-04-01

The aim of the present study was to verify whether penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) occurred in Brazil prior to the beginning of the 21st century, and to verify whether ampicillin susceptibility can predict susceptibility to other β-lactams in E. faecalis with this inconsistent phenotype. The presence of polymorphisms in the pbp4 gene and genetic diversity among the isolates were investigated. Of 21 PRASEF analyzed, 5 (23.8%) and 4 (19.0%) were imipenem and piperacillin resistant simultaneously by disk diffusion and broth dilution respectively, contradicting the current internationally accepted standards of susceptibility testing. Sequencing of pbp4 gene revealed an amino acid substitution (Asp-573→Glu) in all PRASEF isolates but not in the penicillin-susceptible, ampicillin-susceptible E. faecalis. Most PRASEF (90.5%) had related pulsed-field gel electrophoresis profiles, but were different from other PRASEF described to date. Results demonstrate that penicillin-resistant, ampicillin-susceptible phenotype was already a reality in the 1990s in E. faecalis isolates in different Brazilian states, and some of these isolates were also imipenem- and piperacillin-resistant; therefore, internationally accepted susceptibility criteria cannot be applied to these isolates. According to pbp4 gene sequencing, this study suggests that a specific amino acid substitution in pbp4 gene found in all PRASEF analyzed is associated with penicillin resistance. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Antimicrobial Susceptibility of Haemophilus parainfluenzae

PubMed Central

Mayo, Joan B.; McCarthy, Laurence R.

1977-01-01

Fifty random clinical isolates of Haemophilus parainfluenzae were tested for their susceptibility to 10 antibiotics by a microtiter broth dilution method. Three of the strains tested were resistant to ampicillin, whereas eight were resistant to tetracycline. All strains tested were susceptible to chloramphenicol, kanamycin, gentamicin, cephalothin, and colistin. The ranges of minimal inhibitory concentrations for the three remaining antibiotics were: 0.5 to ≥128 μg of penicillin G per ml, 0.03 to 4 μg of carbenicillin per ml, and 1 to 16 μg of erythromycin per ml. Elevated minimal inhibitory concentrations for penicillin and carbenicillin were noted for the three ampicillin-resistant strains. Tests for beta-lactamase production demonstrated the presence of this enzyme in each of the three ampicillin-resistant strains. PMID:587028

Gut microbiota recovery and immune response in ampicillin-treated mice.

PubMed

Castro-Mejía, Josué L; Jakesevic, Maja; Fabricius, Niels F; Krych, Łukasz; Nielsen, Dennis S; Kot, Witold; Bendtsen, Katja M; Vogensen, Finn K; Hansen, Camilla H F; Hansen, Axel K

2018-06-01

Ampicillin is applied in rodents to induce a temporarily depleted microbiota. To elucidate whether bacteria are just temporarily suppressed or fully eliminated, and how this affects the re-colonisation process, we compared the microbiota and immune system in conventionally housed untreated mice with newly weaned ampicillin treated mice subsequently housed in either a microbe containing environment or in an isolator with only host associated suppressed bacteria to recolonize the gut. Two weeks ampicillin treatment induced a seemingly germ-free state with no bacterial DNA to reveal. Four weeks after treatment caeca were still significantly enlarged in both treated groups, but bacteria re-appeared even in isolator housed mice. While some suppressed bacteria were able to recover and even dominate the community, the abundances and composition were far from the untreated mice and differed between isolator and conventional housing. The treatment reduced the innate cytokine expressions at least for three weeks after treatment, and had a non-lasting reducing impact on the regulatory T cells, and a more lasting impact on the natural killer T cells. We conclude that temporary ampicillin treatment suppresses the majority but does not eliminate all the gut microbiota members. The re-colonisation process is as such influenced by both suppressed host associated bacteria and by environmental bacteria. Treated mice do not re-obtain a complex gut microbiota comparable to untreated mice, and the immune response and gut morphology reflect this. This is a concern when comparing host parameters sensitive to microbial regulation after an antibiotic-induced temporarily "germ-free" state. Copyright © 2018 Elsevier Ltd. All rights reserved.

High prevalence of antimicrobial resistance among Shigella isolates in the United States tested by the National Antimicrobial Resistance Monitoring System from 1999 to 2002.

PubMed

Sivapalasingam, Sumathi; Nelson, Jennifer M; Joyce, Kevin; Hoekstra, Mike; Angulo, Frederick J; Mintz, Eric D

2006-01-01

Shigella spp. infect approximately 450,000 persons annually in the United States, resulting in over 6,000 hospitalizations. Since 1999, the National Antimicrobial Resistance Monitoring System (NARMS) for Enteric Bacteria has tested every 10th Shigella isolate from 16 state or local public health laboratories for susceptibility to 15 antimicrobial agents. From 1999 to 2002, NARMS tested 1,604 isolates. Among 1,598 isolates identified to species level, 1,278 (80%) were Shigella sonnei, 295 (18%) were Shigella flexneri, 18 (1%) were Shigella boydii, and 7 (0.4%) were Shigella dysenteriae. Overall, 1,251 (78%) were resistant to ampicillin and 744 (46%) were resistant to trimethoprim-sulfamethoxazole (TMP-SMX). Prevalence of TMP-SMX- or ampicillin- and TMP-SMX-resistant Shigella sonnei isolates varied by geographic region, with lower rates in the South and Midwest regions (TMP-SMX resistance, 27% and 30%, respectively; ampicillin and TMP-SMX resistance, 25% and 22%, respectively) and higher rates in the East and West regions (TMP-SMX resistance, 66% and 80%, respectively; ampicillin and TMP-SMX resistance, 54% and 65%, respectively). Nineteen isolates (1%) were resistant to nalidixic acid (1% of S. sonnei and 2% of S. flexneri isolates); 12 (63%) of these isolates had decreased susceptibility to ciprofloxacin. One S. flexneri isolate was resistant to ciprofloxacin. All isolates were susceptible to ceftriaxone. Since 1986, resistance to ampicillin and TMP-SMX has dramatically increased. Shigella isolates in the United States remain susceptible to ciprofloxacin and ceftriaxone.

High Prevalence of Antimicrobial Resistance among Shigella Isolates in the United States Tested by the National Antimicrobial Resistance Monitoring System from 1999 to 2002

PubMed Central

Sivapalasingam, Sumathi; Nelson, Jennifer M.; Joyce, Kevin; Hoekstra, Mike; Angulo, Frederick J.; Mintz, Eric D.

2006-01-01

Shigella spp. infect approximately 450,000 persons annually in the United States, resulting in over 6,000 hospitalizations. Since 1999, the National Antimicrobial Resistance Monitoring System (NARMS) for Enteric Bacteria has tested every 10th Shigella isolate from 16 state or local public health laboratories for susceptibility to 15 antimicrobial agents. From 1999 to 2002, NARMS tested 1,604 isolates. Among 1,598 isolates identified to species level, 1,278 (80%) were Shigella sonnei, 295 (18%) were Shigella flexneri, 18 (1%) were Shigella boydii, and 7 (0.4%) were Shigella dysenteriae. Overall, 1,251 (78%) were resistant to ampicillin and 744 (46%) were resistant to trimethoprim-sulfamethoxazole (TMP-SMX). Prevalence of TMP-SMX- or ampicillin- and TMP-SMX-resistant Shigella sonnei isolates varied by geographic region, with lower rates in the South and Midwest regions (TMP-SMX resistance, 27% and 30%, respectively; ampicillin and TMP-SMX resistance, 25% and 22%, respectively) and higher rates in the East and West regions (TMP-SMX resistance, 66% and 80%, respectively; ampicillin and TMP-SMX resistance, 54% and 65%, respectively). Nineteen isolates (1%) were resistant to nalidixic acid (1% of S. sonnei and 2% of S. flexneri isolates); 12 (63%) of these isolates had decreased susceptibility to ciprofloxacin. One S. flexneri isolate was resistant to ciprofloxacin. All isolates were susceptible to ceftriaxone. Since 1986, resistance to ampicillin and TMP-SMX has dramatically increased. Shigella isolates in the United States remain susceptible to ciprofloxacin and ceftriaxone. PMID:16377666

Controlled Release of Antibiotics from Biodegradable Microcapsules for Wound Infection Control.

DTIC Science & Technology

1982-06-18

evaporation and phase separation methods were used in formulating the microcapsules .(l1) The microencapsulation process will be described in detail in a...intensity to the antibiotic content. Usi.ng both microencapsulation processes, 14C-labeled ampicillin anhydypte microcapsules were synthesized.(12...excellent technical assistance. .. . . g .SETTERSTROM, TICE, LEWIS, and-MEYERS TABLE 1. IN VIVO AMPICILLIN MICROCAPSULES EVALUATED MICROENCAPSULATION

Synthesis of netlike gold nanoparticles using ampicillin as a stabilizing reagent and its application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Y.Z., E-mail: singyuanzhi@sina.com; Zhou, J.F.; Song, Y., E-mail: songyang@mail.buct.edu.cn

Graphical abstract: Electrochemical deposition of netlike gold nanoparticles (GNPs) on the surface of glassy carbon electrode and preparation of netlike GNPs in aqueous solution using ampicillin as a stabilizing reagent were proposed. The catalytic properties of netlike gold nanoparticles on the glassy carbon electrode for dopamine were demonstrated. The results indicate that the netlike gold nanoparticle modified electrode has an excellent repeatability and reproducibility. Display Omitted Highlights: ► Synthesis of netlike gold nanoparticles using ampicillin as a stabilizing reagent. ► Excellent repeatability and reproducibility of netlike gold nanoparticle modified glassy carbon electrode. ► The catalytic properties of netlike gold nanoparticlemore » for dopamine. -- Abstract: Electrochemical deposition of netlike gold nanoparticles on the surface of glassy carbon electrode and preparation of netlike GNPs in aqueous solution using ampicillin as a stabilizing reagent were proposed. The netlike gold nanoparticles were characterized by scanning electron microscope, transmission electron microscope, infrared spectrometer, UV spectrophotometer, powder X-ray diffractometer and electrochemical analyzer. The catalysis of the netlike gold nanoparticles on the glassy carbon electrode for dopamine was demonstrated. The results indicate that the gold nanoparticle modified electrode has an excellent repeatability and reproducibility.« less

Subinhibitory concentrations of cell wall synthesis inhibitors promote biofilm formation of Enterococcus faecalis

NASA Astrophysics Data System (ADS)

Yu, Wen; Hallinen, Kelsey; Wood, Kevin

Enterococcus faecalis are commonly associated with hospital acquired infections, because they readily form biofilms on instruments and medical devices. Biofilms are inherently more resistant to killing by antibiotics compared to planktonic bacteria, in part because of their heterogeneous spatial structure. Surprisingly, however, subminimal inhibitory concentrations (sub-MICs) of some antibiotics can actually promote biofilm formation. Unfortunately, much is still unknown about how low drug doses affect the composition and spatial structure of the biofilm. In this work, we investigate the effects of sub-MICs of ampicillin on the formation of E. faecalis biofilms. First, we quantified biofilm mass using crystal violet staining in polystyrene microtiter plates. We found that total biofilm mass is increased over a narrow range of ampicillin concentrations before ultimately declining at higher concentrations. Second, we show that sub-MICs of ampicillin can increase mass of E. faecalis biofilms while simultaneously increasing extracellular DNA/RNA and changing total number of viable cells under confocal microscopy. Further, we use RNA-seq to identify genes differentially expressed under sub-MICs of ampicillin. Finally, we show a mathematical model to explain this phenomenon. This work was funded by The Hartwell Foundation Individual Biomedical Research Award and NSF CAREER 1553208 to KBW.

In vitro and in vivo synergism between amoxicillin and clavulanic acid against ampicillin-resistant Haemophilus influenzae type b.

PubMed Central

Yogev, R; Melick, C; Kabat, W J

1981-01-01

Eight strans of ampicillin-resistant beta-lactamase-producing Haemophilus influenzae type b were studied in vitro for synergy between amoxicillin and clavulanic acid. The minimal inhibitory concentrations for amoxicillin alone were 6.25 to 12.5 microgram/ml, and for clavulanic acid alone they were 12.5 to 25 microgram/ml. However, seven of eight strains were inhibited by a combination of 0.36 microgram of amoxicillin and 0.36 microgram of clavulanic acid per ml. Infant rat models of bacteremia and meningitis were used to test the efficacy of amoxicillin and clavulanic acid alone and in combination upon four strains of ampicillin-resistant H. influenzae. Neither amoxicillin alone (27 animals) nor clavulanic acid alone (20 animals) sterilized the blood or cerebrospinal fluid of the animals. In contrast, 30 of 33 blood cultures and 29 of 33 cerebrospinal fluid cultures were sterile when a combination of the two drugs in the same dosages was used. The observed in vitro and in vivo synergism between amoxicillin and clavulanic acid suggests that the combination may be effective therapy for invasive infections in humans caused by ampicillin-resistant H. influenzae type b. PMID:6973952

CLINICAL CHARACTERISTICS AND ANTIBIOTIC RESISTANCE PATTERN OF PATHOGENS IN PEDIATRIC URINARY TRACT INFECTION.

PubMed

Amornchaicharoensuk, Yupaporn

2016-09-01

Medical records of children less than 15-years of age admitted to hospital for urinary tract infection (UTI) from January 2010 to December 2014 were reviewed. Among 100 children (59% males and 41% females) with upper UTI, the most common pathogen (88%) was Escherichia coli, of which 69% were nonextended spectrum beta-lactamase (ESBL) and 19 % ESBL producers. Resistance to ampicillin and trimethoprim/sulfamethoxazole was 90% and 60%, respectively. All ESBL-producing E. coli were resistant to ampicillin and third generation cephalosporins (cefotaxime and ceftriaxone), while 87% and 1.5% of non ESBL-producing E. coli were resistant to ampicillin and the two third generation cephalosporins, respectively. These data highlight the high prevalence of ESBL-producing E. coli in pediatric UTI and the potential problem in treating such infections.

Synergistic antibacterial effect of apigenin with β-lactam antibiotics and modulation of bacterial resistance by a possible membrane effect against methicillin resistant Staphylococcus aureus.

PubMed

Akilandeswari, K; Ruckmani, K

2016-12-30

Methicillin-resistant Staphylococcus aureus (MRSA) infections are easily spread among infected patients, where resistance has dramatically increased resulted in serious health issues. Therefore, there is a need to develop alternative natural or combination drug therapies. Apigenin (AP) is a natural poly phenolic flavonoid has been found to possess many beneficial biological actions. The aim of this study was to investigate the anti-MRSA efficacy and synergistic effect of apigenin (AP) and in combination with ampicillin (AM) and ceftriaxone (CEF). The antibacterial activity of apigenin was assessed by the broth macro dilution, checkerboard micro dilution method and time-kill assay.  The mode of action was studied by outer and inner membrane permeabilisation assays, scanning electron microscopy and transmission electron microscopy. The minimum inhibitory concentration (MIC) of apigenin against gram positive and gram negative strain ranged from 32.5 to 62.5µg/ml. In checkerboard method apigenin markedly reduced the MIC of the antibiotics ampicillin 800 µg/ml shifted to 107 µg/ml (AM+AP) and ceftriaxone 58 µg/ml shifted to 2.6 µg/ml (CEF+AP) against MRSA. The synergistic activity of ampicillin and ceftriaxone plus apigenin combinations with FIC indices (CI) between 0.18-0.47. The modulation of methicillin-resistance by apigenin significantly enhanced the activities of ampicillin and ceftriaxone. The result of time-kill assays of the two drug combinations AM +AP and CEF+AP against MRSA showed significant inhibitory effect and reduced the colony count by approximately 99% after 8 h The results for outer membrane (OM) and inner membrane (IM) permeabilization showed that ampicillin and ceftriaxone in combination with apigenin damaged MRSA cytoplasmic membrane and caused subsequent leakage of intracellular constituents. Electron microscopy clearly showed that the above said combination also caused marked morphological damage of cell wall, cell shape and plasma membrane of this strain. From these results, it can be concluded that apigenin has the synergistic effect with ampicillin and ceftriaxone to reverse bacterial resistance against MRSA.

Modeling the growth dynamics of multiple Escherichia coli strains in the pig intestine following intramuscular ampicillin treatment.

PubMed

Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo; Græsbøll, Kaare; Toft, Nils; Matthews, Louise; Nielsen, Søren Saxmose; Olsen, John Elmerdahl

2016-09-06

This study evaluated how dosing regimen for intramuscularly-administered ampicillin, composition of Escherichia coli strains with regard to ampicillin susceptibility, and excretion of bacteria from the intestine affected the level of resistance among Escherichia coli strains in the intestine of nursery pigs. It also examined the dynamics of the composition of bacterial strains during and after the treatment. The growth responses of strains to ampicillin concentrations were determined using in vitro growth curves. Using these results as input data, growth predictions were generated using a mathematical model to simulate the competitive growth of E. coli strains in a pig intestine under specified plasma concentration profiles of ampicillin. In vitro growth results demonstrated that the resistant strains did not carry a fitness cost for their resistance, and that the most susceptible strains were more affected by increasing concentrations of antibiotics that the rest of the strains. The modeling revealed that short treatment duration resulted in lower levels of resistance and that dosing frequency did not substantially influence the growth of resistant strains. Resistance levels were found to be sensitive to the number of competing strains, and this effect was enhanced by longer duration of treatment. High excretion of bacteria from the intestine favored resistant strains over sensitive strains, but at the same time it resulted in a faster return to pre-treatment levels after the treatment ended. When the duration of high excretion was set to be limited to the treatment time (i.e. the treatment was assumed to result in a cure of diarrhea) resistant strains required longer time to reach the previous level. No fitness cost was found to be associated with ampicillin resistance in E. coli. Besides dosing factors, epidemiological factors (such as number of competing strains and bacterial excretion) influenced resistance development and need to be considered further in relation to optimal treatment strategies. The modeling approach used in the study is generic, and could be used for prediction of the effect of treatment with other drugs and other administration routes for effect on resistance development in the intestine of pigs.

Ampicillin-Resistant Non-β-Lactamase-Producing Haemophilus influenzae in Spain: Recent Emergence of Clonal Isolates with Increased Resistance to Cefotaxime and Cefixime▿

PubMed Central

García-Cobos, Silvia; Campos, José; Lázaro, Edurne; Román, Federico; Cercenado, Emilia; García-Rey, César; Pérez-Vázquez, María; Oteo, Jesús; de Abajo, Francisco

2007-01-01

The sequence of the ftsI gene encoding the transpeptidase domain of penicillin-binding protein 3 (PBP 3) was determined for 354 nonconsecutive Haemophilus influenzae isolates from Spain; 17.8% of them were ampicillin susceptible, 56% were β-lactamase nonproducing ampicillin resistant (BLNAR), 15.8% were β-lactamase producers and ampicillin resistant, and 10.4% displayed both resistance mechanisms. The ftsI gene sequences had 28 different mutation patterns and amino acid substitutions at 23 positions. Some 93.2% of the BLNAR strains had amino acid substitutions at the Lys-Thr-Gly (KTG) motif, the two most common being Asn526 to Lys (83.9%) and Arg517 to His (9.3%). Amino acid substitutions at positions 377, 385, and 389, which conferred cefotaxime and cefixime MICs 10 to 60 times higher than those of susceptible strains, were found for the first time in Europe. In 72 isolates for which the repressor acrR gene of the AcrAB efflux pump was sequenced, numerous amino acid substitutions were found. Eight isolates with ampicillin MICs of 0.25 to 2 μg/ml showed changes that predicted the early termination of the acrR reading frame. Pulsed-field gel electrophoresis analysis demonstrated that most BLNAR strains were genetically diverse, although clonal dissemination was detected in a group of isolates presenting with increased resistance to cefotaxime and cefixime. Background antibiotic use at the community level revealed a marked trend toward increased amoxicillin-clavulanic acid consumption. BLNAR H. influenzae strains have arisen by vertical and horizontal spread and have evolved to adapt rapidly to the increased selective pressures posed by the use of oral penicillins and cephalosporins. PMID:17470649

Direct detection by real-time PCR of ftsI gene mutations affecting MICs of β-lactam agents for Haemophilus influenzae isolates from meningitis.

PubMed

Kishii, Kozue; Morozumi, Miyuki; Chiba, Naoko; Ono, Akiko; Ubukata, Kimiko

2011-10-01

One resistance mechanism of Haemophilus influenzae to ampicillin involves decreased affinity of penicillin-binding protein (PBP) 3 for β-lactam antibiotics reflecting amino acid substitutions in PBP3 encoded by the ftsI gene. Three amino acid substitutions, Ser385Thr, Arg517His, and Asn526Lys, are especially responsible for β-lactam resistance. We constructed a new real-time polymerase chain reaction (PCR) to directly detect these substitutions in addition to 16S ribosomal RNA (rRNA), cap, and bla(TEM) genes. Our real-time PCR was evaluated using 206 clinical H. influenzae strains isolated from pediatric patients with meningitis. Relative sensitivities and specificities of real-time PCR were 90.5-100% and 96.3-100% for all resistance classes compared with our previously reported conventional PCR. In addition, real-time PCR shortened time required from 3 h by conventional PCR to 1.5 h. When correlations between combinations of amino acid substitutions in the ftsI gene detected by real-time PCR and minimum inhibitory concentrations (MICs) of β-lactam antibiotics were evaluated, MIC(90)s of ampicillin for β-lactamase-nonproducing ampicillin-intermediate-resistant strains with Asn526Lys, β-lactamase-nonproducing, ampicillin-resistant strains with Ser385Thr, and β-lactamase-nonproducing ampicillin-resistant strains with both Asn526Lys and Ser385Thr, respectively, were two, four, and eight times higher than those for sensitive strains. Similarly, MIC(90)s of cephalosporins for these strains, respectively, were two, 16-32, and 16-32 times higher than those for sensitive strains. Thus, real-time PCR can guide antibiotic use.

Molecular epidemiology of antibiotic resistance of Salmonella enteritidis during a 7-year period in Greece.

PubMed Central

Tassios, P T; Markogiannakis, A; Vatopoulos, A C; Katsanikou, E; Velonakis, E N; Kourea-Kremastinou, J; Legakis, N J

1997-01-01

A significant increase in the frequency of isolation of Salmonella enteritidis has been observed during recent years in Greece, parallelled by an increasing rate of resistance of this organism to antibiotics. A substantial proportion of ampicillin- and doxycycline-resistant isolates exhibited cross-resistance to drugs of other classes, such as sulfonamides and streptomycin. Isolates of human origin were overall less resistant than those of animal or food-feed origin. Indeed, strains associated with animal infections were characterized by the highest rates of resistance to several antibiotics. These phenotypic data were correlated with genotypic information concerning two distinct populations: isolates from all sources that were resistant only to ampicillin, the drug toward which resistance rates were highest, and a control group of sensitive isolates. Ampicillin resistance was due to a 34-MDa conjugative plasmid. DNA fingerprinting by macrorestriction of genomic DNA revealed two types, A and B, common to both ampicillin-resistant and -sensitive strains, with 80 to 90% of strains being of type A. However, a third type, C, was specific for the sensitive population, representing 17% of those strains. Therefore, although the majority of resistant isolates were genetically related to sensitive ones, there existed a susceptible clone which had not acquired any resistance traits. PMID:9163436

Treatment with protein synthesis inhibitors improves outcomes from secondary bacterial pneumonia following influenza

PubMed Central

Karlström, Åsa; Boyd, Kelli L.; English, B. Keith; McCullers, Jonathan A.

2008-01-01

Pneumonia as a secondary infection after influenza is a major cause of excess morbidity and mortality despite the availability and use of antibiotics active against Streptococcus pneumoniae. We hypothesized that use of a bacteriostatic protein synthesis inhibitor would improve outcomes by reducing the inflammatory response. BALB/c mice infected with influenza virus and super-infected with Streptococcus pneumoniae were treated with either the cell wall active antibiotic ampicillin or protein synthesis inhibitors clindamycin or azithromycin. Ampicillin therapy performed significantly worse (56% survival) in the model compared to clindamycin therapy either alone (82%) or in combination with ampicillin (80%) and to azithromycin (92%). Improved survival appeared to be mediated by decreased inflammation manifested as lower levels of inflammatory cells and pro-inflammatory cytokines in the lungs, and less severe histopathology. These data suggest that beta-lactam therapy may not be optimal as first line treatment of community acquired pneumonia when it follows influenza. PMID:19113989

In Vitro Activity of Cephalothin and Three Penicillins Against Escherichia coli and Proteus Species

PubMed Central

Barry, Arthur L.; Hoeprich, Paul D.

1973-01-01

The susceptibility of clinical isolates of Escherichia coli (67) and Proteus species (58) to cephalothin, ampicillin, benzyl penicillin, and phenoxymethyl penicillin was determined in vitro by using broth dilution and disk diffusion tests. The data were correlated by using a four-category scheme for interpreting minimal inhibitory concentrations (groups 1 to 4) as recommended by a subcommittee of an international collaborative study of susceptibility testing. With cephalothin and ampicillin, groups 1 (susceptible) and 2 (moderately susceptible) were susceptible by the disk test, and with benzyl penicillin, similar results were observed when the interpretive zone standards were changed. Strains categorized as group 4 (very resistant) were resistant by the disk method, but group 3 (moderately resistant) strains were not adequately distinguished by disk testing. Group 3 susceptibility to benzyl and phenoxymethyl penicillins can be predicted by extrapolating results from tests with ampicillin disks. PMID:4202343

Comparison between a Direct-Flow SPR Immunosensor for Ampicillin and a Competitive Conventional Amperometric Device: Analytical Features and Possible Applications to Real Samples

PubMed Central

Tomassetti, Mauro; Merola, Giovanni; Martini, Elisabetta; Campanella, Luigi; Sanzò, Gabriella; Favero, Gabriele; Mazzei, Franco

2017-01-01

In this research, we developed a direct-flow surface plasmon resonance (SPR) immunosensor for ampicillin to perform direct, simple, and fast measurements of this important antibiotic. In order to better evaluate the performance, it was compared with a conventional amperometric immunosensor, working with a competitive format with the aim of finding out experimental real advantages and disadvantages of two respective methods. Results showed that certain analytical features of the new SPR immunodevice, such as the lower limit of detection (LOD) value and the width of the linear range, are poorer than those of a conventional amperometric immunosensor, which adversely affects the application to samples such as natural waters. On the other hand, the SPR immunosensor was more selective to ampicillin, and measurements were more easily and quickly attained compared to those performed with the conventional competitive immunosensor. PMID:28394296

[Comparison of techniques for coliform bacteria extraction from sediment of Xochimilco Lake, Mexico].

PubMed

Fernández-Rendón, Carlos L; Barrera-Escorcia, Guadalupe

2013-01-01

The need to separate bacteria from sediment in order to appropriately count them has led to test the efficacy of different techniques. In this research, traditional techniques such as manual shaking, homogenization, ultrasonication, and surfactant are compared. Moreover, the possibility of using a set of enzymes (pancreatine) and an antibiotic (ampicillin) for sediment coliform extraction is proposed. Samples were obtained from Xochimilco Lake in Mexico City. The most probable number of coliform bacteria was determined after applying the appropriate separation procedure. Most of the techniques tested led to numbers similar to those of the control (manual shaking). Only with the use of ampicillin, a greater total coliform concentration was observed (Mann-Whitney, z = 2.09; p = 0.03). It is possible to propose the use of ampicillin as a technique for total coliform extraction; however, it is necessary to consider sensitivity of bacteria to the antibiotic.

Metabolism of Penicillins to Penicilloic Acids and 6-Aminopenicillanic Acid in Man and Its Significance in Assessing Penicillin Absorption

PubMed Central

Cole, M.; Kenig, M. D.; Hewitt, Valerie A.

1973-01-01

Penicillins can be metabolized to penicilloic acids in man, the extent being dependent on the penicillin structure. In the phenoxy penicillin series, phenoxymethyl penicillin was found to be particularly unstable, but the higher homologues were more stable. In the isoxazolyl series, oxacillin was unstable, and progressive insertion of halogen in the phenyl ring increased stability. Ampicillin and amoxycillin showed some instability, ampicillin possibly being the more stable. After intramuscular administration, carbenicillin was very stable in the body, ampicillin was fairly stable, and benzyl penicillin was unstable. It is important to take into account the penicilloic acid content of urine when estimating total absorption of a penicillin. Increased stability in the body as well as slower renal clearance can lead to high concentrations in the serum. Penicilloic acids seemed to be more slowly cleared from the body than penicillins. The liver is probably the site of inactivation. PMID:4364176

Determination of flavonoids in Triticum aestivum L. treated with ampicillin

NASA Astrophysics Data System (ADS)

Soran, M. L.; Opriş, O.; Copaciu, F.; Varodi, C.

2012-02-01

Pharmaceutical residues in the environment, and their potential toxic effects, have been recognized as one of the emerging research area in the environmental chemistry. Antibiotics can reach plants from treated soil or due to irrigation. The flavonoids extraction from Triticum aestivum L. treated with ampicillin and separation of flavonoids are presented in this study. There were used classical and modern extraction techniques (maceration, microwave assisted solvents, etc). The efficiency of extraction process was spectrophotometricaly evaluated by determining the total flavonoids content and by HPTLC on silica gel plates using the mixture: carbon tetrachloride - acetone - formic acid (35:11:3, v/v) as mobile phase. The developed plates were inspected both in ultraviolet and visible after visualization with NTS reagent (diphenylboryloxyethylamin). The chromatographic plates were compared in respect to determine the changes in extract composition due to the different extraction techniques. Depending on the concentration of ampicillin administered to plants, comparative studies on flavonoids content were performed.

Inhibition of penicillin-binding protein 2a (PBP2a) in methicillin resistant Staphylococcus aureus (MRSA) by combination of ampicillin and a bioactive fraction from Duabanga grandiflora.

PubMed

Santiago, Carolina; Pang, Ee Leen; Lim, Kuan-Hon; Loh, Hwei-San; Ting, Kang Nee

2015-06-10

The inhibition of penicillin-binding protein 2a (PBP2a) is a promising solution in overcoming resistance of methicillin resistance Staphylococcus aureus (MRSA). A potential approach in achieving this is by combining natural product with currently available antibiotics to restore the activity as well as to amplify the therapeutic ability of the drugs. We studied inhibition effects of a bioactive fraction, F-10 (isolated from the leaves of Duabanga grandiflora) alone and in combination with a beta-lactam drug, ampicillin on MRSA growth and expression of PBP2a. Additionally, phytochemical analysis was conducted on F-10 to identify the classes of phytochemicals present. Fractionation of the ethyl acetate leaf extract was achieved by successive column chromatography which eventually led to isolation of an active fraction, F-10. Both extract and F-10 were analyzed for the presence of major classes of phytochemicals in addition to obtaining a high performance liquid chromatography (HPLC) profile to reveal the complexity of the fraction F-10. Broth microdilution method was employed to determine minimum inhibitory concentration (MIC) of the extract and fractions against MRSA. Evaluation of synergistic activity of the active fraction with ampicillin was determined using checkerboard methodand kinetic growth experiments. Effect of combination treatments on expression of PBP2a, a protein that confers resistance to beta-lactam antibiotics, was elucidated with the Western blot assay. MIC of F-10 against MRSA was 750 mg/L which showed an improved activity by 4-fold compared to its crude extract (MIC = 3000 mg/L). Phytochemical analysis revealed occurrence of tannins, saponin, flavonoids, sterols, and glycosides in F10 fraction. In FIC index interpretation, the most synergistic activity was achieved for combinations of 1/64 × MIC ampicillin + 1/4 × MIC F-10. The combination also evidently inhibited MRSA growth in kinetic growth curve assay. As a result of this synergistic interaction, MIC of ampicillin against MRSA was reduced to 0.78 mg/L (64-fold) from initial value of 50 mg/L. Western blot analysis suggested inhibition of PBP2a in MRSA cultures grown in synergistic combination treatment in which no PBP2a band was expressed. The results demonstrated synergism between fraction F-10 of D. grandiflora with ampicillin in suppressing MRSA growth via PBP2a inhibition.

Synthesis, characterization and evaluation of 1,3,5-triazine aminobenzoic acid derivatives for their antimicrobial activity.

PubMed

Al-Zaydi, Khadijah M; Khalil, Hosam H; El-Faham, Ayman; Khattab, Sherine N

2017-05-10

Replacement of chloride ions in cyanuric chloride give several variants of 1,3,5-triazine derivatives which were investigated as biologically active small molecules. These compounds exhibit antimalarial, antimicrobial, anti-cancer and anti-viral activities, among other beneficial properties. On the other hand, treatment of bacterial infections remains a challenging therapeutic problem because of the emerging infectious diseases and the increasing number of multidrug-resistant microbial pathogens. As multidrug-resistant bacterial strains proliferate, the necessity for effective therapy has stimulated research into the design and synthesis of novel antimicrobial molecules. 1,3,5-Triazine 4-aminobenzoic acid derivatives were prepared by conventional method or by using microwave irradiation. Using microwave irradiation gave the desired products in less time, good yield and higher purity. Esterification of the 4-aminobenzoic acid moiety afforded methyl ester analogues. The s-triazine derivatives and their methyl ester analogues were fully characterized by FT-IR, NMR ( 1 H-NMR and 13 C-NMR), mass spectra and elemental analysis. All the synthesized compounds were evaluated for their antimicrobial activity. Some tested compounds showed promising activity against Staphylococcus aureus and Escherichia coli. Three series of mono-, di- and trisubstituted s-triazine derivatives and their methyl ester analogues were synthesized and fully characterized. All the synthesized compounds were evaluated for their antimicrobial activity. Compounds (10), (16), (25) and (30) have antimicrobial activity against S. aureus comparable to that of ampicillin, while the activity of compound (13) is about 50% of that of ampicillin. Compounds (13) and (14) have antimicrobial activity against E. coli comparable to that of ampicillin, while the activity of compounds (9-12) and (15) is about 50% of that of ampicillin. Furthermore, minimum inhibitory concentrations values for clinical isolates of compounds (10), (13), (14), (16), (25) and (30) were measured. Compounds (10) and (13) were more active against MRSA and E. coli than ampicillin. Invitro cytotoxicity results revealed that compounds (10) and (13) were nontoxic up to 250 µg/mL (with SI = 10) and 125 µg/mL (with SI = 5), respectively. Graphical abstract Three series of mono-, di- and trisubstituted s-triazine derivatives and their methyl ester analogues were synthesized and evaluated for their antimicrobial activity. Several compounds have antimicrobial activity against S. aureus and E. coli comparable to that of ampicillin.

Renal excretion of intravenously infused amoxycillin and ampicillin.

PubMed Central

Sjövall, J; Westerlund, D; Alván, G

1985-01-01

The aim of this study was to determine whether concentration-dependent renal clearance of ampicillin and amoxycillin occurs. The drugs were given as single 20 min i.v. infusions in doses ranging from 1.9 to 2.8 g to nine healthy volunteers using a cross-over design. Plasma and urinary concentrations were determined by a selective liquid chromatographic method using frequent sampling up to 10 and 30 h respectively after termination of the infusion. The renal clearance of the drugs was independent of the plasma concentration. The mean (s.d.) renal clearances of ampicillin and amoxycillin were 167 (24) and 157 (20) ml min-1 1.73 m-2 respectively. The net secretion was about 50% of the total renal clearance of both drugs. The plasma concentration and urinary excretion rate versus time curves indicated a polyexponential decline, which could be described by both a biexponential and a triexponential equation. The former proved to be more reliable, especially in the calculation of micro rate constants. There was a tendency to more sustained plasma concentrations after amoxycillin, also illustrated by a significantly lower mean (s.d.) plasma clearance of this drug, viz. 185 (30) ml min-1 1.73 m-2, as compared to ampicillin, 210 (24) ml min-1 1.73 m-2 (P less than 0.04). There were no major differences in the disposition rate constants and the distribution volumes of ampicillin and amoxycillin. The mean (s.d.) plasma half-life was 1.7 (0.3) h for both drugs. The urinary excretion rate indicated a slower terminal disposition rate however, with ampicillin and amoxycillin half-lives of 3.4 (2.0) and 3.9 (1.2) h respectively. The longer half-life in the terminal phase may be due to increased tubular reabsorption at low urinary concentrations. It was not possible to determine in this study whether the half-life was affected by changes in clearance or volume of distribution. The urinary solubility of the drugs was dependent on pH. This could explain the massive macroscopic crystalluria seen in one subject after amoxycillin. Three hours after termination of the infusion, crystals could no longer be found in the sediment. There was no clinical or laboratory evidence of renal damage. PMID:3986077

Genotypic Characterization of Egypt Enterotoxigenic Escherichia coli Isolates Expressing Coli Surface Antigen 6

DTIC Science & Technology

2013-02-01

47%) of these isolates were resistant to ampicillin, a third (37%) of the isolates were resistant to trimethoprim -sulfamethoxazole, and 24% of the...isolates were tetracycline-resistant. A blaTEM gene was detected in 24 (83%) ampicillin-resistant isolates. Trimethoprim -sulfamethoxazole-resistant...ciprofloxacin (CIP) 5 μg, amikacin (AN) 30 μg, gentamicin (GEN) 10 μg, tetracycline (TET) 30 μg, trimethoprim 1.25 μg / sulfamethoxazole 23.75 μg (SXT

The effects of repeated antibiotic administration to juvenile BALB/c mice on the microbiota status and animal behavior at the adult age.

PubMed

Ceylani, Taha; Jakubowska-Doğru, Ewa; Gurbanov, Rafig; Teker, Hikmet Taner; Gozen, Ayse Gul

2018-06-01

Recent studies carried on germ -free (GF) animal models suggest that the gut microbiota (GM) may play a role in the regulation of anxiety, mood, and cognitive abilities such as memory and learning processes. Consistently, any treatment disturbing the gut microbiota, including the overuse of antibiotics, may influence the brain functions and impact behavior. In the present study, to address this issue, two wide-spectrum antibiotics (ampicillin and cefoperazone, 1 g/l) were repeatedly applied throughout a 6-week period to initially 21-day-old male BALB/c mice. Antibiotics were administered separately or in a mixed fashion. On the completion of the antibiotic treatment, all mice were subjected to the behavioral tests. The serum levels of corticosterone and brain-derived neurotropic factor (BDNF) were assessed. Gut microbiota profiles were obtained by using denaturing gradient gel electrophoresis system, DGGE, from fecal samples. Ampicillin had a greater impact on both, gut microbiota composition and mice behavior compared to cefoperazone. All antibiotic-treated groups manifested a decrease in the locomotor activity and reduced recognition memory. However, the ampicillin-treated groups showed a higher anxiety level as assessed by the open field and the elevated plus maze tests and an increased immobility (behavioral despair) in the forced swim test. Obtained results evidently show that in mice, a repeated antibiotic treatment applied during adolescence, parallel to the changes in GM, affects locomotor activity, affective behavior and cognitive skills in young adults with ampicillin specifically enhancing anxiety- and depressive-like responses. Lower levels of serum BDNF were not associated with cognitive impairment but with changes in affective-like behaviors. Repeated administration of neither ampicillin nor cefoperazone affected basal serum corticosterone levels. This is one of the few studies demonstrating changes in a behavioral phenotype of young-adult subjects who were previously exposed to a repeated antibiotic treatment.

Effects of prophylactic antibiotics on endometrial flora in women with postcesarean endometritis.

PubMed

Newton, E R; Wallace, P A

1998-08-01

To determine the effect of prophylactic antibiotics on endometrial and endocervical microflora upon diagnosis of postcesarean endometritis. The medical records of patients enrolled in open-label comparative trials of therapeutic antibiotics for postpartum endometritis between 1989 and 1994 were reviewed (n = 682). Endometritis was diagnosed by a standard definition that included fever and localizing signs. Endometrial cultures were obtained by a sheathed injection/aspiration technique. Aerobes and anaerobes were isolated by standard microbiologic techniques. The primary outcome, endometrial and endocervical microflora, was compared in women who received intravenous ampicillin (2 g every 6 hours for 1-3 doses), cephalosporin (2 g every 6 hours for 1-3 doses), or no prophylaxis. Secondary outcomes included the cure of endometritis and the prevalence of wound infection in the three groups. Four hundred sixty-five of 682 patients (67%) had a cesarean delivery. One hundred fifty-one patients received ampicillin prophylaxis, 100 patients received cefazolin prophylaxis, 18 patients received extended-spectrum antibiotics, and 196 patients received no prophylaxis. Patients who received cefazolin prophylaxis had a significant increase in enterococcus (P < .05) and a significant decrease in Proteus species (P < .05) from endometrial samples. Patients who received ampicillin prophylaxis had a significant increase of Mycoplasma species (P < .05), Klebsiella pneumoniae (P < .0001), Escherichia coli (P = .04), and any aerobic gram-negative rod (P = .003) from endometrial samples. Ampicillin prophylaxis was associated with a decrease in Prevotella bivia (P < .05) and any anaerobe (P < .01). Endometritis cure rates were similar between prophylaxis groups and between prophylaxis and treatment groups. However, the cefazolin prophylaxis followed by cephalosporin treatment was associated with more wound infections (19%) than other prophylaxis and treatment groups, (6%, P < .01). Ampicillin and cefazolin prophylaxis alters endometrial and endocervical microflora of women who develop endometritis. Whereas these changes had no effect on endometritis cure rate (power > 80%), the association between cefazolin prophylaxis followed by an extended-spectrum cephalosporin and wound infection may warrant caution against the use of the combination.

The efficacy of ampicillin and Lactobacillus casei rhamnosus in the active management of preterm premature rupture of membranes remote from term

PubMed Central

Kavak, Salih Burcin; Kavak, Ebru; Ilhan, Rasit; Atilgan, Remzi; Arat, Ozgur; Deveci, Ugur; Sapmaz, Ekrem

2014-01-01

Background We aimed to investigate the treatment efficacy of ampicillin prophylaxis accompanied by Lactobacillus casei rhamnosus over the latency period following preterm premature rupture of membranes (PPROM). Methods Records of 40 patients who presented with PPROM between 230/7–316/7 weeks were analyzed retrospectively. Patients were divided into two groups: group 1 (n=20), treated with ampicillin; and group 2 (n=20), treated with ampicillin plus L. casei rhamnosus. Clinical and laboratory parameters were compared. Delta (Δ) values of each laboratory parameter were calculated by subtracting the value at delivery from the values at admission to the clinic. Results Gestational weeks at delivery (28.1±0.3 weeks versus 31.5±0.4 weeks), latency periods (12.3±1.5 days versus 41.4±4.4 days), 5-minute APGAR scores (6.8±0.1 versus 7.8±0.1), and birth weights (1,320±98 g versus 1,947±128 g) were significantly higher in group 2. White blood cell (WBC) (12,820±353/mm3 versus 11,107±298/mm3), and neutrophil counts (10.7±0.5×103/L versus 8.2±0.5×103/L) were significantly lower in group 2 at delivery. The ΔWBC (2,295±74/mm3 versus −798±−406/mm3), ΔC-reactive protein (5±0.04 mg/L versus 1.6±0.2 mg/L), and Δneutrophil (3±0.2×103/L versus 0.2±−0.1×103/L) were significantly lower in group 2. Conclusion It seems that addition of L. casei rhamnosus to ampicillin prolongs the latency period in patients with PPROM remote from term. PMID:25210439

Near Absence of Vancomycin-Resistant Enterococci but High Carriage Rates of Quinolone-Resistant Ampicillin-Resistant Enterococci among Hospitalized Patients and Nonhospitalized Individuals in Sweden

PubMed Central

Torell, Erik; Cars, Otto; Olsson-Liljequist, Barbro; Hoffman, Britt-Marie; Lindbäck, Johan; Burman, Lars G.

1999-01-01

Rates of colonization with enterococci with acquired resistance to vancomycin (vancomycin-resistant enterococci [VRE]) and ampicillin (ampicillin-resistant enterococci [ARE]) were determined by using fecal samples from 670 nonhospitalized individuals and 841 patients in 27 major hospitals. Of the hospitalized patients, 181 (21.5%) were carriers of ARE and 9 (1.1%) were carriers of VRE. In univariate analyses, length of hospital stay (odds ratio [OR], 4.6; 95% confidence interval [CI], 2.5 to 8.9) and antimicrobial therapy (OR, 4.7; 95% CI, 3.3 to 6.7) were associated with ARE colonization, as were prior treatment with penicillins (OR, 3.1; 95% CI, 1.8 to 5.5), cephalosporins (OR, 2.9; 95% CI, 1.7 to 5.0), or quinolones (OR, 2.7; 95% CI, 1.5 to 4.7). In logistic regression analysis, antimicrobial therapy for at least 5 days was independently associated with ARE carriage (adjusted OR, 3.8; 95% CI, 2.6 to 5.4). Over 90% of the ARE isolates were fluoroquinolone resistant, whereas 14% of the ampicillin-susceptible Enterococcus faecium isolates were fluoroquinolone resistant. ARE carriage rates correlated with the use of fluoroquinolones (P = 0.04) but not with the use of ampicillin (P = 0.68) or cephalosporins (P = 0.40). All nine VRE isolates were E. faecium vanB and were found in one hospital. Seven of these isolates were related according to their types as determined by pulsed-field gel electrophoresis. Among the nonhospitalized individuals, the ARE carriage rate was lower (6%; P < 0.05), and only one person, who had recently returned from Africa, harbored VRE (E. faecium vanA). The absence of VRE colonization in nonhospitalized individuals reflects an epidemiological situation in Sweden radically different from that in countries in continental Europe where glycopeptides have been widely used for nonmedical purposes. PMID:10523543

Presence of the resistance genes vanC1 and pbp5 in phenotypically vancomycin and ampicillin susceptible Enterococcus faecalis.

PubMed

Schwaiger, Karin; Bauer, Johann; Hörmansdorfer, Stefan; Mölle, Gabriele; Preikschat, Petra; Kämpf, Peter; Bauer-Unkauf, Ilse; Bischoff, Meike; Hölzel, Christina

2012-08-01

Ampicillin and vancomycin are important antibiotics for the therapy of Enterococcus faecalis infections. The ampicillin resistance gene pbp5 is intrinsic in Enterococcus faecium. The vanC1 gene confers resistance to vancomycin and serves as a species marker for Enterococcus gallinarum. Both genes are chromosomally located. Resistance to ampicillin and vancomycin was determined in 484 E. faecalis of human and porcine origin by microdilution. Since E. faecalis are highly skilled to acquire resistance genes, all strains were investigated for the presence of pbp5 (and, in positive strains, for the penicillin-binding protein synthesis repressor gene psr) and vanC1 (and, in positive strains, for vanXYc and vanT) by using polymerase chain reaction (PCR). One porcine and one human isolate were phenotypically resistant to ampicillin; no strain was vancomycin resistant. Four E. faecalis (3/1 of porcine/human origin) carried pbp5 (MIC=1 mg/L), and four porcine strains were vanC1 positive (minimum inhibitory concentration [MIC]=1 mg/L). Real-time reverse transcriptase (RT)-PCR revealed that the genes were not expressed. The psr gene was absent in the four pbp5-positive strains; the vanXYc gene was absent in the four vanC1-positive strains. However, vanT of the vanC gene cluster was detected in two vanC1-positive strains. To our knowledge, this is the first report on the presence of pbp5, identical with the "E. faecium pbp5 gene," and of vanC1/vanT in E. faecalis. Even if resistance is not expressed in these strains, this study shows that E. faecalis have a strong ability to acquire resistance genes-and potentially to spread them to other bacteria. Therefore, close monitoring of this species should be continued.

Zero-magnetic field effect in pathogen bacteria

NASA Astrophysics Data System (ADS)

Creanga, D. E.; Poiata, A.; Morariu, V. V.; Tupu, P.

2004-05-01

Two lots of Gram-negative bacterial strains were tested for antibiotic drug resistance after exposure to zero-magnetic field. We found that the magneto-sensitive strains represent half of the analyzed samples (three Pseudomonas and five Enterobacter strains), some of them presenting two-three times modified resistance to antibiotic, while others revealed eight or 16 times changed resistance. Pseudomonas strain magnetic sensitivity is revealed better by ampicillin and tetracycline, while Enterobacter strain magnetic sensitivity is revealed better by ampicillin, kanamycin and ofloxacin.

What about antibiotic resistance in Neisseria lactamica?

PubMed

Arreaza, L; Salcedo, C; Alcalá, B; Vázquez, J A

2002-03-01

The in vitro activity of penicillin, ampicillin, cefotaxime, ceftriaxone, rifampicin and ciprofloxacin against 286 Neisseria lactamica isolates was determined by agar dilution and the category of susceptibility was analysed in accordance with the criteria used for Neisseria meningitidis. All isolates were considered to have intermediate susceptibility to penicillin. A total of 1.7% of the isolates were resistant to ampicillin but all were susceptible to cefotaxime and ceftriaxone. Rifampicin MICs ranged between 0.12 and 2 mg/L. Six isolates (2.1%) showed decreased susceptibility to ciprofloxacin.

Congenital syphilis presenting as Jarisch-Herxheimer reaction at birth.

PubMed

Hori, Hideyuki; Sato, Yoshitake; Shitara, Tosiji

2015-04-01

We report a rare case of congenital syphilis (CS) presenting as Jarisch-Herxheimer reaction (JHR) at birth. The mother (primigravida) presented in labor and had not received antenatal care. She was given prophylactic ampicillin 2 g i.v. on admission and delivered shortly thereafter. The male infant (2899 g) had normal vital signs, conjunctival congestion, splenohepatomegaly, and maculopapular rash with small blisters over the entire body. Serological tests on the infant and mother confirmed CS. The infant was given i.v. ampicillin for 14 days (50 mg/kg per day until day 3, 100 mg/kg per day thereafter). One hour after the first injection, the infant developed fever (39°C), tachycardia and tachypnea without worsening of rash. Vital signs improved gradually. The rash reduced markedly at postnatal day 1, and disappeared without pigmentation at day 3. This was considered a JHR following ampicillin injection given to the mother before delivery and to the infant after birth. © 2015 Japan Pediatric Society.

Multidrug-resistant Commensal Escherichia coli in Children, Peru and Bolivia

PubMed Central

Pallecchi, Lucia; Benedetti, Marta; Fernandez, Connie; Vallejos, Yolanda; Guzman, Elisa; Villagran, Ana Liz; Mantella, Antonia; Lucchetti, Chiara; Bartalesi, Filippo; Strohmeyer, Marianne; Bechini, Angela; Gamboa, Herlan; Rodríguez, Hugo; Falkenberg, Torkel; Kronvall, Göran; Gotuzzo, Eduardo; Paradisi, Franco; Rossolini, Gian Maria

2006-01-01

Using a rapid screening method, we investigated the prevalence of fecal carriage of antimicrobial drug–resistant Escherichia coli in 3,174 healthy children from 4 urban settings in Peru and Bolivia. High resistance rates were observed for ampicillin (95%), trimethoprim-sulfamethoxazole (94%), tetracycline (93%), streptomycin (82%), and chloramphenicol (70%). Lower resistance rates were observed for nalidixic acid (35%), kanamycin (28%), gentamicin (21%), and ciprofloxacin (18%); resistance to ceftriaxone and amikacin was uncommon (<0.5%). In a random sample of 1,080 resistant E. coli isolates, 90% exhibited a multidrug-resistance (MDR) phenotype. The 2 most common MDR phenotypes (ampicillin/tetracycline/trimethoprim-sulfamethoxazole and ampicillin/tetracycline/trimethoprim-sulfamethoxazole/chloramphenicol) could be transferred en bloc in conjugation experiments. The most common acquired resistance genes were blaTEM, tet(A), tet(B), drfA8, sul1, sul2, and catI. These findings underscore the magnitude of the problem of antimicrobial drug resistance in low-resource settings and the urgent need for surveillance and control of this phenomenon. PMID:16707045

Piezoelectric immunosensors for the detection of individual antibiotics and the total content of penicillin antibiotics in foodstuffs.

PubMed

Karaseva, N A; Ermolaeva, T N

2014-03-01

Piezoelectric immunosensors on the basis of homologous and group-specificantibodies have been developed for detecting penicillin G, ampicillin, and the total content of penicillin antibiotics. The receptor coating of the sensor was obtained by the immobilization of penicillin G or ampicillin hapten-protein conjugates on the polypyrrole film obtained by electropolymerization and activated by glutaraldehyde. The affinity constants and the cross reactivity coefficients have been calculated. This made it possible to estimate the affinity and specificity of the polyclonal and monoclonal antibodies used. The calibration curves are linear in the range of concentrations 2.5-250.0 ng ml(-1) (penicillin G), 2.5-500.0 ng ml(-1) (ampicillin), and 1-500 ng ml(-1) (group of penicillin). The limits of detection are 0.8 ng ml(-1), 3.9 ng ml(-1), which are lower than MRL, established for penicillin antibiotics. The sensors were tested in detecting penicillins in milk, pork, beef, liver. Copyright © 2013 Elsevier B.V. All rights reserved.

Brief communication: treatment of Enterococcus faecalis endocarditis with ampicillin plus ceftriaxone.

PubMed

Gavaldà, Joan; Len, Oscar; Miró, José M; Muñoz, Patricia; Montejo, Miguel; Alarcón, Aristides; de la Torre-Cisneros, Julián; Peña, Carmen; Martínez-Lacasa, Xavier; Sarria, Cristina; Bou, Germán; Aguado, José M; Navas, Enrique; Romeu, Joan; Marco, Francesc; Torres, Carmen; Tornos, Pilar; Planes, Ana; Falcó, Vicenç; Almirante, Benito; Pahissa, Albert

2007-04-17

High-level aminoglycoside resistance (HLAR) that precludes bactericidal synergism with penicillins or glycopeptides and nephrotoxicity related to aminoglycoside treatment are major problems in treating Enterococcus faecalis endocarditis. To evaluate the efficacy and safety of ampicillin plus ceftriaxone for treating endocarditis due to E. faecalis with and without HLAR. Observational, open-label, nonrandomized, multicenter clinical trial. 13 centers in Spain. 21 patients with HLAR E. faecalis endocarditis and 22 patients with non-HLAR E. faecalis endocarditis. All were at risk for nephrotoxicity related to aminoglycoside use. 6-week course of intravenous ampicillin, 2 g every 4 hours, plus intravenous ceftriaxone, 2 g every 12 hours. Clinical and microbiological outcomes. The clinical cure rate at 3 months was 67.4% (29 of 43 patients) among all episodes. During treatment, 28.6% of patients with HLAR E. faecalis endocarditis and 18.2% of patients with non-HLAR E. faecalis endocarditis died of infection-related causes. The rate of clinical and microbiological cure in patients who completed the protocol was 100% in the HLAR E. faecalis endocarditis group. No episodes of breakthrough bacteremia occurred, although there were 2 relapses in the non-HLAR E. faecalis endocarditis group. Treatment was withdrawn in 1 case because of fever and skin rash. The study had a small sample and was observational. The combination of ampicillin and ceftriaxone is effective and safe for treating HLAR E. faecalis endocarditis and could be a reasonable alternative for patients with non-HLAR E. faecalis endocarditis who are at increased risk for nephrotoxicity.

Characterisation of penicillin and tetracycline resistance in Staphylococcus aureus isolated from bovine milk samples in Minas Gerais, Brazil.

PubMed

Martini, Caroline L; Lange, Carla C; Brito, Maria Avp; Ribeiro, João B; Mendonça, Letícia C; Vaz, Eliana K

2017-05-01

This Regional Research Communication describes the characterisation of ampicillin, penicillin and tetracycline resistance in Staphylococcus aureus isolated from bovine subclinical mastitis in Minas Gerais State, Brazil. Ninety S. aureus isolates from bovine mastitis exhibiting phenotypic resistance to ampicillin, penicillin and/or tetracycline were selected for this study. The minimum inhibitory concentration (MIC) of each antibiotic was determined using the E-Test® and the production of beta-lactamase was determined by cefinase disks. The resistance genes blaZ, tet(K), tet(L), tet(M), and tet(O) were investigated by PCR in all of the isolates. The MIC results classified 77, 83 and 71% of the isolates as resistant to ampicillin, penicillin and tetracycline, respectively. The MIC50 and MIC90 were, respectively, 1 and 2 µg/ml for ampicillin, 0·5 and 1 µg/ml for penicillin and 32 and 64 µg/ml for tetracycline. Eighty-six per cent of beta-lactamase producing isolates were detected. Of the 90 isolates investigated, 97% amplified blaZ, 84% amplified tet(K), 9% amplified tet(L), 2% amplified tet(M) and 1% amplified tet(O). Seventy-nine isolates (88%) showed blaZ together with at least one tet gene. S. aureus isolates showed high MIC50 and MIC90 values for the three antimicrobials. The blaZ and tet(K) genes were widespread in the herds studied, and most of the isolates harboured blaZ and tet(K) concomitantly.

Susceptibility to antimicrobial agents of Streptococcus suis capsular type 2 strains isolated from pigs.

PubMed

Seol, B; Kelneric, Z; Hajsig, D; Madic, J; Naglic, T

1996-03-01

The minimal inhibitory concentrations (MICs) for thirty-three epidemiologicaly unrelated clinical isolates of Streptococcus suis capsular type 2 were determined in relation to ampicillin, ampicillin-sulbactam, amoxicillin, clavulanate-amoxicillin, penicillin G, cephalexin, gentamicin, streptomycin, erythromycin, tylosin and doxycycline, using the microtitre broth dilution procedure described by the U.S. National Committee for Clinical Laboratory Standards (NCCLS). Gentamicin was the most active compound tested, with an MIC for 90% of the strains tested (MIC(90)) of 0.4 mg/L. Overall, 70% of strains were resistant to doxycycline (MIC(90) > or = 100.0 mg/L), followed by penicillin G (51% of strains) (MIC(90) + or = 100.0 mg/L). Resistance to amoxicillin and ampicillin was 36.4% (MIC(90) 12.5 mg/L) and 33.3% (MIC(90) 50.0 mg/L), respectively. 15.2% of S. suis strains were resistant to streptomycin, tylosin and cephalexin with MIC90 values of 25.0 mg/L, 12.5 mg/L and 25.0 mg/L, respectively. A combination of ampicillin and sulbactam (MIC(90) 6.3 mg/L) and a combination of amoxicillin and clavulanate (MIC(90) 3.1 mg/L) as well as erythromycin (1.6 mg/L) were of the same efficacy, with a total of 9.1% resistant S. suis strains. This high percentage of resistance to doxycycline and penicillin G precludes the use of these antibiotics as empiric therapy of swine diseases.

Antianaerobic activity of sulopenem compared to six other agents.

PubMed

Ednie, Lois M; Appelbaum, Peter C

2009-05-01

Agar dilution MIC methodology was used to compare the activity of sulopenem with those of amoxicillin/clavulanate, ampicillin/sulbactam, piperacillin-tazobactam, imipenem, clindamycin, and metronidazole against 431 anaerobes. Overall, MIC(50)/(90) values were as follows: sulopenem, 0.25/1.0 microg/ml; amoxicillin/clavulanate, 0.5/2.0 microg/ml; ampicillin/sulbactam, 0.5/4.0 microg/ml; piperacillin/tazobactam, 0.25/8.0 microg/ml; imipenem, 0.06/1.0 microg/ml; clindamycin, 0.25/16.0 microg/ml; and metronidazole, 1.0/4.0 microg/ml.

Synergy of arbekacin-based combinations against vancomycin hetero-intermediate Staphylococcus aureus.

PubMed

Lee, Ji Young; Oh, Won Sup; Ko, Kwan Soo; Heo, Sang Taek; Moon, Chi Sook; Ki, Hyun Kyun; Kiem, Sungmin; Peck, Kyong Ran; Song, Jae Hoon

2006-04-01

This study was undertaken to evaluate the in vitro activities of arbekacin-based combination regimens against vancomycin hetero-intermediate Staphylococcus aureus (hetero-VISA). Combinations of arbekacin with vancomycin, rifampin, ampicillin-sulbactam, teicoplanin, or quinupristin-dalfopristin against seven hetero-VISA strains and two methicillin-resistant S. aureus strains were evaluated by the time-kill assay. The combinations of arbekacin with vancomycin, teicoplanin, or ampicillin-sulbactam showed the synergistic interaction against hetero-VISA strains. Data suggest that these arbekacin-based combination regimens may be useful candidates for treatment options of hetero-VISA infections.

Zinc Finger Nuclease: A New Approach to Overcome Beta-Lactam Antibiotic Resistance

PubMed Central

Shahbazi Dastjerdeh, Mansoureh; Kouhpayeh, Shirin; Sabzehei, Faezeh; Khanahmad, Hossein; Salehi, Mansour; Mohammadi, Zahra; Shariati, Laleh; Hejazi, Zahra; Rabiei, Parisa; Manian, Mostafa

2016-01-01

Background: The evolution of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) has been accelerated recently by the indiscriminate application of antibiotics. Antibiotic resistance has challenged the success of medical interventions and therefore is considered a hazardous threat to human health. Objectives: The present study aimed to describe the use of zinc finger nuclease (ZFN) technology to target and disrupt a plasmid-encoded β-lactamase, which prevents horizontal gene transfer-mediated evolution of ARBs. Materials and Methods: An engineered ZFN was designed to target a specific sequence in the ampicillin resistance gene (ampR) of the pTZ57R plasmid. The Escherichia coli bacteria already contained the pZFN kanamycin-resistant (kanaR) plasmid as the case or the pP15A, kanaR empty vector as the control, were transformed with the pTZ57R; the ability of the designed ZFN to disrupt the β-lactamase gene was evaluated with the subsequent disturbed ability of the bacteria to grow on ampicillin (amp) and ampicillin-kanamycin (amp-kana)-containing media. The effect of mild hypothermia on the ZFN gene targeting efficiency was also evaluated. Results: The growth of bacteria in the case group on the amp and amp-kana-containing media was significantly lower compared with the control group at 37°C (P < 0.001). Despite being more efficient in hypothermic conditions at 30°C (P < 0.001), there were no significant associations between the incubation temperature and the ZFN gene targeting efficiency. Conclusions: Our findings revealed that the ZFN technology could be employed to overcome ampicillin resistance by the targeted disruption of the ampicillin resistance gene, which leads to inactivation of β-lactam synthesis. Therefore, ZFN technology could be engaged to decrease the antibiotic resistance issue with the construction of a ZFN archive against different ARGs. To tackle the resistance issue at the environmental level, recombinant phages expressing ZFNs against different ARGs could be constructed and released into both hospital and urban wastewater systems. PMID:27099691

Testing plasmid stability of Escherichia coli using the Continuously Operated Shaken BIOreactor System.

PubMed

Sieben, Michaela; Steinhorn, Gregor; Müller, Carsten; Fuchs, Simone; Ann Chin, Laura; Regestein, Lars; Büchs, Jochen

2016-11-01

Plasmids are common vectors to genetically manipulate Escherichia coli or other microorganisms. They are easy to use and considerable experience has accumulated on their application in heterologous protein production. However, plasmids can be lost during cell growth, if no selection pressure like, e.g., antibiotics is used, hampering the production of the desired protein and endangering the economic success of a biotechnological production process. Thus, in this study the Continuously Operated Shaken BIOreactor System (COSBIOS) is applied as a tool for fast parallel testing of strain stability and operation conditions and to evaluate measures to counter such plasmid loss. In specific, by applying various ampicillin concentrations, the lowest effective ampicillin dosage is investigated to secure plasmid stability while lowering adverse ecological effects. A significant difference was found in the growth rates of plasmid-bearing and plasmid-free cells. The undesired plasmid-free cells grew 30% faster than the desired plasmid-bearing cells. During the testing of plasmid stability without antibiotics, the population fraction of plasmid-bearing cells rapidly decreased in continuous culture to zero within the first 48 h. An initial single dosage of ampicillin did not prevent plasmid loss. By contrast, a continuous application of a low dosage of 10 µg/mL ampicillin in the feed medium maintained plasmid stability in the culture. Consequently, the COSBIOS is an apt reactor system for measuring plasmid stability and evaluating methods to enhance this stability. Hence, decreased production of heterologous protein can be prevented. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1418-1425, 2016. © 2016 American Institute of Chemical Engineers.

Antimicrobial susceptibility patterns of Shigella isolates in Foodborne Diseases Active Surveillance Network (FoodNet) sites, 2000-2010.

PubMed

Shiferaw, Beletshachew; Solghan, Suzanne; Palmer, Amanda; Joyce, Kevin; Barzilay, Ezra J; Krueger, Amy; Cieslak, Paul

2012-06-01

Treatment of shigellosis with appropriate antimicrobial agents shortens duration of illness and bacterial shedding, but resistance to commonly used agents is increasing. We describe resistance patterns among Shigella isolates in the United States with use of linked data from the Foodborne Diseases Active Surveillance Network (FoodNet) and National Antimicrobial Resistance Monitoring System (NARMS). FoodNet sites send every 20th Shigella isolate to the NARMS laboratory for susceptibility testing. During 2000-2010, the NARMS laboratory tested 1376 Shigella isolates from FoodNet sites. Of 1118 isolates (81%) linked to FoodNet, 826 (74%) were resistant to ampicillin, 649 (58%) to streptomycin, 402 (36%) to trimethoprim-sulfamethoxazole (TMP-SMX), 355 (32%) to sulfamethoxazole-sulfisoxazole, 312 (28%) to tetracycline, 19 (2%) to nalidixic acid, and 6 (0.5%) to ciprofloxacin. The proportion of Shigella isolates with resistance to TMP-SMX was 40% among white persons, 58% among Hispanic persons, and 75% among persons with a history of international travel. Resistance to at least TMP-SMX and ampicillin was present in 25% of isolate, and 5% were resistant to ampicillin, TMP-SMX, and chloramphenicol. Overall, 5% of isolates showed multidrug resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole-sulfisoxazole, and tetracycline, including 49 Shigella flexneri (33%) and 3 Shigella sonnei (0.3%) isolates. Male individuals were more likely than female individuals to be infected with a multidrug-resistant strain (7% versus 3%; P < .01). Antimicrobial resistance differed by race, ethnicity, age, travel, and species. Resistance to commonly used antibiotics is high; therefore, it is important to look at the susceptibility pattern before starting treatment.

Molecular characterization and antibiotic susceptibility of Haemophilus influenzae clinical isolates.

PubMed

K L Ç, Hüseyin; Akyol, Selcan; Parkan, Õmür Mustafa; Dinç, Gõkçen; Sav, Hafize; Aydemir, Gonca

2017-03-01

Haemophilus influenzae can cause invasive and severe infections in both adults and children such as otitis media, sinusitis, pneumonia, meningitis and bacteremia. The emerging antibiotic resistance in recent years against ampicillin and several other antibiotics among strains of H. influenzae gives cause for serious concern. Here, we investigate ß-lactamase (BL) activity in clinical isolates of H. influenzae, profile their resistance to antibiotics, and characterize the clonal relationship of the isolates. Antibiotic susceptibilities of 92 clinical isolates of H. influenzae (March 2011-May 2012) were determined using the disk diffusion method according to the Clinical & Laboratory Standards Institute (CLSI), and BL activity was detected using the nitrocefin disk method. The Rep-PCR method was used to characterize clonality of the isolates. All strains were found to be susceptible to levofloxacin and cefotaxime. Four isolates out of 92 (4.3%) were found resistant to ampicillin, one isolate (1.1%) was resistant to amoxicillin/clavulanic acid, 21 isolates (22.8%) were resistant to trimethoprim-sulfamethoxazole (SXT), and three isolates (3.3%) showed BL activity. One strain was BL-negative but resistant to ampicillin. The three isolates with BL activity and four isolates with resistance to ampicillin did not have a clonal relationship. Three distinct clones [clone A (with subclones A1 and A2), clone B, and clone C] were identified among the SXT-resistant strains. Most of the H. influenzae isolates in this study were susceptible to the antibiotics while SXT resistance was relatively more prevalent, which suggests that significant obstacles in the therapeutic use of antibiotics against H. influenzae strains are not expected in our region.

An evaluation of E. coli in urinary tract infection in emergency department at KAMC in Riyadh, Saudi Arabia: retrospective study.

PubMed

Alanazi, Menyfah Q; Alqahtani, Fulwah Y; Aleanizy, Fadilah S

2018-02-09

Urinary tract infection (UTIS) is a common infectious disease in which level of antimicrobial resistance are alarming worldwide. Therefore, this study aims to describe the prevalence and the resistance pattern of the main bacteria responsible for UTIS Escherichia coli (E. coli). Retrospective chart review for patients admitted to emergency department and diagnosed with UTIS at KAMC, in Riyadh, Saudi Arabia between January to March 2008 was performed. Antimicrobial susceptibility to ampicillin, augmentin (amoxicillin/clavulanate), cefazolin, co-trimoxazole (sulfamethoxazole/trimethoprim), ciprofloxacin, and nitrofurantoin, and cefpodoxime was determined for 101 E. coli urinary isolates. Escherichia coli was the most prevalent pathogen contributing to UTIS representing 93.55, 60.24, and 45.83% of all pathogen isolated from urine culture of pediatric, adult, and elderly, respectively. High rates of resistance to ampicillin (82.76, 58, and 63.64%) and co-trimoxazole (51.72, 42, and 59.09%), among E. coli isolated from pediatric, adult and elderly respectively. Nitrofurantoin was the most active agent, followed by ciprofloxacin, augmentin and cefazolin. 22.77% of E. coli isolates exhibited multiple drug resistance (MDR). Among 66 and 49 isolates resistant to ampicillin and co-trimoxazole, respectively, 34.84 and 42.85% were MDR. In contrast, all isolates resistant to augmentin and nitrofurantoin were MRD, while 72.7 and 82.4% of isolates resistant to ciprofloxacin and cefazolin were MDR. High resistance was observed to ampicillin and co-trimoxazole which commonly used as empirical treatments for UTIS, limiting their clinical use. This necessitates continuous surveillance for resistance pattern of uropathogens against antibiotics.

First-Line Antimicrobial Resistance Patterns of Escherichia coli in Children With Urinary Tract Infection in Emergency Department and Primary Care Clinics.

PubMed

Ahmed, M Nadeem; Vannoy, Debby; Frederick, Ann; Chang, Sandy; Lawler, Elisabeth

2016-01-01

To identify risk factors for antibiotic resistance to Escherichia coli (E. coli) in children with urinary tract infections (UTIs) in emergency room and primary care clinics. This is a cross-sectional study of children 0 to 18 years of age reported to have E coli-positive UTIs whose medical and laboratory records were systematically reviewed. Compared with girls, boys were 2.29 times (confidence interval [CI] = 1.30-4.02) more likely to have E coli isolates resistant to ampicillin and 2 times more likely (CI = 1.13-3.62) to have isolates resistant to trimethoprim-sulfamethoxazole (TMP/SMX). Patients with genitourinary abnormalities were 1.57 times more likely to be resistant to ampicillin (CI = 1.03-2.41) and 1.86 times to TMP/SMX (CI = 1.18-2.94). Higher rates of ampicillin and TMP/SMX resistant urinary E coli isolates were observed among boys and children with a history of genitourinary abnormality. Age and recent antibiotic prescription are also potential risk factors for resistance. © The Author(s) 2015.

Antimicrobial resistance among Escherichia coli that cause childhood community-acquired urinary tract infections in Northern Italy.

PubMed

Caracciolo, Alessandra; Bettinelli, Alberto; Bonato, Claudio; Isimbaldi, Clementina; Tagliabue, Alessandro; Longoni, Laura; Bianchetti, Mario G

2011-01-06

Resistance rate of Escherichia coli against antimicrobials that are commonly prescribed in pediatric urinary tract infections is currently a matter of concern. The antimicrobial susceptibility patterns of uropathogenic Escherichia coli strains to the common antibimcrobials ampicillin, cotrimoxazole, coamoxyclav, ceftazidime, ceftriaxone, nitrofurantoin, and gentamycin were determined in 177 children aged from 2 to 36 months. They presented with their first symptomatic community acquired urinary tract infection at the Department of Pediatrics, San Leopoldo Mandic Hospital, Merate-Lecco. High rates of ampicillin (inpatients: 50%; outpatients: 52%) resistance were identified. The resistance for cotrimoxazole (inpatients: 22%; outpatients: 15%) and especially coamoxyclav (inpatients: 6%; outpatients: 10%) was less pronounced than that to ampicillin. No resistance or less than 1% of resistance was identified for ceftazidime, ceftriaxone, nitrofurantoin, and gentamycin both in inpatients and in outpatients. Italian children affected with a community acquired urinary tract infection are initially managed orally with coamoxyclav or parenterally with ceftriaxone. The results of the present retrospective analysis support this attitude. Parenteral ceftriaxone or an aminoglycoside should be considered for patients on antimicrobial prophylaxis or recently prescribed antimicrobials.

Antianaerobic Activity of Sulopenem Compared to Six Other Agents ▿

PubMed Central

Ednie, Lois M.; Appelbaum, Peter C.

2009-01-01

Agar dilution MIC methodology was used to compare the activity of sulopenem with those of amoxicillin/clavulanate, ampicillin/sulbactam, piperacillin-tazobactam, imipenem, clindamycin, and metronidazole against 431 anaerobes. Overall, MIC50/90 values were as follows: sulopenem, 0.25/1.0 μg/ml; amoxicillin/clavulanate, 0.5/2.0 μg/ml; ampicillin/sulbactam, 0.5/4.0 μg/ml; piperacillin/tazobactam, 0.25/8.0 μg/ml; imipenem, 0.06/1.0 μg/ml; clindamycin, 0.25/16.0 μg/ml; and metronidazole, 1.0/4.0 μg/ml. PMID:19223615

Effect of electron irradiation and packaging atmosphere on the survival of aeromonas hydrophila in minced poultry meat

NASA Astrophysics Data System (ADS)

Stecchini, M. L.; Sarais, I.; Del Torre, M.; Fuochi, P. G.

1995-02-01

Resistance to electron irradiation of Aeromonas hydrophila inoculated in minced poultry meat packed in presence of air or under vacuum was examined. Surviving bacteria were counted on starch ampicillin agar containing 100 μg/ml of ampicillin. Radiation resistance, expressed as D 10 values, was calculated from the survival curves and found to be 0.12 and 0.12 kGy in poultry meat packed in air or under vacuum respectively. Storage at 2°C of meat samples irradiated at 0.5 kGy further reduced the number of A. hydrophila.

Enterococcus faecium PBP5-S/R, the missing link between PBP5-S and PBP5-R.

PubMed

Pietta, Ester; Montealegre, Maria Camila; Roh, Jung Hyeob; Cocconcelli, Pier Sandro; Murray, Barbara E

2014-11-01

During a study to investigate the evolution of ampicillin resistance in Enterococcus faecium, we observed that a number of E. faecium strains, mainly from the recently described subclade A2, showed PBP5 sequences in between PBP5-S and PBP5-R. These hybrid PBP5-S/R patterns reveal a progression of amino acid changes from the S form to the R form of this protein; however, these changes do not strictly correlate with changes in ampicillin MICs. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Single oral dose of 1-5g. talampicillin in the treatment of gonorrhoea.

PubMed Central

Willcox, R R

1976-01-01

81 patients have been treated with single oral doses of 1-5 g. (6 tablets) of talampicillin without probenecid. The failure rate amongst those followed was only 4-2 per cent. No side-effects were reported. These results were superior to those obtained with 2-0g. or equivalent of ampicillin, amoxycillin, or pivampicillin with probenecid. Talampicillin is thus the most potent ampicillin-like antibiotic so far available for the treatment of gonorrhoea and is capable of curing the disease with a smaller single dose without probenecid than is necessary for other preparations. PMID:1276866

Antimicrobial susceptibility and serotypes of Actinobacillus (Haemophilus) pleuropneumoniae recovered from Missouri swine.

PubMed

Fales, W H; Morehouse, L G; Mittal, K R; Bean-Knudsen, C; Nelson, S L; Kintner, L D; Turk, J R; Turk, M A; Brown, T P; Shaw, D P

1989-01-01

The antimicrobial susceptibility of 73 Actinobacillus (Haemophilus) pleuropneumoniae isolates from swine in Missouri was determined with a microdilution minimal inhibitory concentration test system. Serotyping was accomplished by means of co-agglutination. Serotype 1 (39/73) and serotype 5 (30/73) were commonly found, whereas serotype 7 (4/73) was infrequently encountered. Most isolates (MIC90) were found susceptible to ampicillin (amoxicillin), cephalothin, penicillin, erythromycin, gentamicin, and kanamycin. Marked resistance was found with oxytetracycline, tylosin, and sulfadimethoxine. The data indicate that use of ampicillin (amoxicillin) or penicillin may correlate well with the favorable outcome of treatment.

Synergy of Arbekacin-based Combinations Against Vancomycin Hetero-intermediate Staphylococcus aureus

PubMed Central

Lee, Ji-Young; Oh, Won Sup; Ko, Kwan Soo; Heo, Sang Taek; Moon, Chi Sook; Ki, Hyun Kyun; Kiem, Sungmin; Peck, Kyong Ran

2006-01-01

This study was undertaken to evaluate the in vitro activities of arbekacin-based combination regimens against vancomycin hetero-intermediate Staphylococcus aureus (hetero-VISA). Combinations of arbekacin with vancomycin, rifampin, ampicillin-sulbactam, teicoplanin, or quinipristin-dalfopristin against seven hetero-VISA strains and two methicillin-resistant S. aureus strains were evaluated by the time-kill assay. The combinations of arbekacin with vancomycin, teicoplanin, or ampicillin-sulbactam showed the synergistic interaction against hetero-VISA strains. Data suggest that these arbekacin-based combination regimens may be useful candidates for treatment options of hetero-VISA infections. PMID:16614499

Antibiotic resistant bacteria in urban sewage: Role of full-scale wastewater treatment plants on environmental spreading.

PubMed

Turolla, A; Cattaneo, M; Marazzi, F; Mezzanotte, V; Antonelli, M

2018-01-01

The presence of antibiotic resistant bacteria (ARB) in wastewater was investigated and the role of wastewater treatment plants (WWTPs) in promoting or limiting antibiotic resistance was assessed. Escherichia coli (E. coli) and total heterotrophic bacteria (THB) resistance to ampicillin, chloramphenicol and tetracycline was monitored in three WWTPs located in Milan urban area (Italy), differing among them for the operating parameters of biological process, for the disinfection processes (based on sodium hypochlorite, UV radiation, peracetic acid) and for the discharge limits to be met. Wastewater was collected from three sampling points along the treatment sequence (WWTP influent, effluent from sand filtration, WWTP effluent). Antibiotic resistance to ampicillin was observed both for E. coli and for THB. Ampicillin resistant bacteria in the WWTP influents were 20-47% of E. coli and 16-25% of THB counts. A limited resistance to chloramphenicol was observed only for E. coli, while neither for E. coli nor for THB tetracycline resistance was observed. The biological treatment and sand filtration led to a decrease in the maximum percentage of ampicillin-resistant bacteria (20-29% for E. coli, 11-21% for THB). However, the conventionally adopted parameters did not seem adequate to support an interpretation of WWTP role in ARB spread. Peracetic acid was effective in selectively acting on antibiotic resistant THB, unlike UV radiation and sodium hypochlorite. The low counts of E. coli in WWTP final effluents in case of agricultural reuse did not allow to compare the effect of the different disinfection processes on antibiotic resistance. Copyright © 2017 Elsevier Ltd. All rights reserved.

[The effect of selected antibiotics on microorganisms contaminating boar ejaculate].

PubMed

Mazurová, J; Vinter, P

1991-04-01

The occurrence of microorganisms, including their total counts in boar native ejaculates, was investigated in two stages; the objective of this investigation also was to determine contamination after the sperms were treated with diluents containing the antibiotics ampicillin, gentamycin, apramycin, cefoxitin, or antibiotic combinations penicillin + streptomycin, ampicillin + cefoxitin, gentamycin + cefoxitin and ampicillin + gentamycin. The representation of bacterial species and total counts of microbes in 1 ml diluted sperm stored at a temperature of about 18 degrees C were determined in 24, 48 and 72 h after dilution. The microorganisms were cultivated from all native ejaculates. Proteus sp. (63.3%) and Pseudomonas aeruginosa (51.5% of the total number of examined samples) were the most frequent species. The number of contaminated diluted ejaculates ranged from 12.5 to 95.8% in 24 h after dilution, from 12.5 to 98.5% in 48 h and from 16.8 to 95.8% of the total number of examined ejaculates in 72 h. The occurrence of microorganisms correlated mostly with the efficiency spectrum of the antibiotics or their combinations. The average counts of microorganisms in 1 ml of native ejaculate made 2,363,000 in stage I and 1,472,108 in stage II. The highest average counts in 1 ml of diluted sperm were found in ejaculates containing cefoxitin and apramycin. Gentamycin was the most effective antibiotic used as a sole component (average counts of microorganisms CPM in 1 ml were 416 in 24 h, 955 in 48 h and 2260 in 72 h after dilution); ampicillin and gentamycin were the most efficient combination (14--20--21). This combination exerted very good effects also on Proteus sp. and Pseudomonas aeruginosa.

A Novel Prokaryotic Green Fluorescent Protein Expression System for Testing Gene Editing Tools Activity Like Zinc Finger Nuclease.

PubMed

Sabzehei, Faezeh; Kouhpayeh, Shirin; Dastjerdeh, Mansoureh Shahbazi; Khanahmad, Hossein; Salehi, Rasoul; Naderi, Shamsi; Taghizadeh, Razieh; Rabiei, Parisa; Hejazi, Zahra; Shariati, Laleh

2017-01-01

Gene editing technology has created a revolution in the field of genome editing. The three of the most famous tools in gene editing technology are zinc finger nucleases (ZFNs), transcription activator-like effector nucleases, clustered regularly interspaced short palindromic repeats (CRISPR), and CRISPR-associated systems. As their predictable nature, it is necessary to assess their efficiency. There are some methods for this purpose, but most of them are time labor and complicated. Here, we introduce a new prokaryotic reporter system, which makes it possible to evaluate the efficiency of gene editing tools faster, cheaper, and simpler than previous methods. At first, the target sites of a custom ZFN, which is designed against a segment of ampicillin resistance gene, were cloned on both sides of green fluorescent protein (GFP) gene to construct pPRO-GFP. Then pPRO-GFP was transformed into Escherichia coli TOP10F' that contains pZFN (contains expression cassette of a ZFN against ampicillin resistant gene), or p15A-KanaR as a negative control. The transformed bacteria were cultured on three separate media that contained ampicillin, kanamycin, and ampicillin + kanamycin; then the resulted colonies were assessed by flow cytometry. The results of flow cytometry showed a significant difference between the case (bacteria contain pZFN) and control (bacteria contain p15A, KanaR) in MFI (Mean Fluorescence Intensity) ( P < 0.0001). According to ZFN efficiency, it can bind and cut the target sites, the bilateral cutting can affect the intensity of GFP fluorescence. Our flow cytometry results showed that this ZFN could reduce the intensity of GFP color and colony count of bacteria in media containing amp + kana versus control sample.

A Novel Prokaryotic Green Fluorescent Protein Expression System for Testing Gene Editing Tools Activity Like Zinc Finger Nuclease

PubMed Central

Sabzehei, Faezeh; Kouhpayeh, Shirin; Dastjerdeh, Mansoureh Shahbazi; Khanahmad, Hossein; Salehi, Rasoul; Naderi, Shamsi; Taghizadeh, Razieh; Rabiei, Parisa; Hejazi, Zahra; Shariati, Laleh

2017-01-01

Background: Gene editing technology has created a revolution in the field of genome editing. The three of the most famous tools in gene editing technology are zinc finger nucleases (ZFNs), transcription activator-like effector nucleases, clustered regularly interspaced short palindromic repeats (CRISPR), and CRISPR-associated systems. As their predictable nature, it is necessary to assess their efficiency. There are some methods for this purpose, but most of them are time labor and complicated. Here, we introduce a new prokaryotic reporter system, which makes it possible to evaluate the efficiency of gene editing tools faster, cheaper, and simpler than previous methods. Materials and Methods: At first, the target sites of a custom ZFN, which is designed against a segment of ampicillin resistance gene, were cloned on both sides of green fluorescent protein (GFP) gene to construct pPRO-GFP. Then pPRO-GFP was transformed into Escherichia coli TOP10F’ that contains pZFN (contains expression cassette of a ZFN against ampicillin resistant gene), or p15A-KanaR as a negative control. The transformed bacteria were cultured on three separate media that contained ampicillin, kanamycin, and ampicillin + kanamycin; then the resulted colonies were assessed by flow cytometry. Results: The results of flow cytometry showed a significant difference between the case (bacteria contain pZFN) and control (bacteria contain p15A, KanaR) in MFI (Mean Fluorescence Intensity) (P < 0.0001). Conclusion: According to ZFN efficiency, it can bind and cut the target sites, the bilateral cutting can affect the intensity of GFP fluorescence. Our flow cytometry results showed that this ZFN could reduce the intensity of GFP color and colony count of bacteria in media containing amp + kana versus control sample. PMID:29285485

Antimicrobial susceptibility of Brachyspira spp. isolated from commercial laying hens and free-living wild mallards (Anas platyrhynchos).

PubMed

Jansson, Désirée S; Pringle, Märit

2011-08-01

In vitro antimicrobial susceptibility to tylosin, valnemulin, tiamulin, doxycycline, lincomycin and ampicillin was investigated by broth dilution in 48 Brachyspira spp. isolates from commercial laying hens (n=30) and free-living wild mallards (Anas platyrhynchos) (n=18). Presumed pathogens (Brachyspira alvinipulli, Brachyspira intermedia, Brachyspira pilosicoli), commensals (Brachyspira murdochii, Brachyspira innocens, "Brachyspira pulli"), and isolates of undetermined species affiliation were included. The laying hens had not been exposed to therapeutic levels of antimicrobials for at least 50 weeks before sampling, and low levels of environmental antimicrobial exposure were presumed in mallards. No isolates with decreased susceptibility to tylosin, valnemulin, tiamulin or doxycycline were found. Decreased susceptibility to lincomycin (minimum inhibitory concentration 16 µg/ml) was detected in two isolates (Brachyspira sp.) from laying hens. Five isolates showed decreased susceptibility to ampicillin (minimum inhibitory concentration 16 to >32 µg/ml), including two "B. pulli" and one B. alvinipulli from laying hens, and isolates of B. pilosicoli and "B. pulli" from mallards. Decreased susceptibility to ampicillin was associated with β-lactamase activity in four isolates. A new variant of a class D β-lactamase gene designated bla (oxa-192) was identified in a B. pilosicoli isolate of mallard origin. This is the first time the genetic basis for antimicrobial resistance is described in Brachyspira spp. from a free-living wild bird. Isolates displaying decreased susceptibility to ampicillin were accompanied by fully susceptible isolates of the same species or other genotypes within three laying hen flocks. This underlines the need for performing antimicrobial susceptibility tests on single clones/genotypes, and to analyse multiple isolates from the same flock.

Multidrug resistance in pediatric urinary tract infections.

PubMed

Gaspari, Romolo J; Dickson, Eric; Karlowsky, James; Doern, Gary

2006-01-01

Urinary tract infections (UTIs) represent a common infection in the pediatric population. Escherichia coli is the most common uropathogen in children, and antimicrobial resistance in this species complicates the treatment of pediatric UTIs. Despite the impact of resistance on empiric antibiotic choice, there is little data on multidrug resistance in pediatric patients. In this paper, we describe characteristics of multidrug-resistant E. coli in pediatric patients using a large national database of uropathogens antimicrobial sensitivities. Antimicrobial susceptibility patterns to commonly prescribed antibiotics were performed on uropathogens isolated from children presenting to participating hospitals between 1999 and 2001. Data were analyzed separately for four pediatric age groups. Single and multidrug resistance to ampicillin, amoxicillin-clavulanate, cefazolin, ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole (TMP-SMX) were performed on all specimens. There were a total of 11,341 E. coli urine cultures from 343 infants (0-4 weeks), 1,801 toddlers (5 weeks-24 months), 6,742 preteens (2-12 years), and 2,455 teens (13-17 years). E. coli resistance to ampicillin peaked in toddlers (52.8%) but was high in preteens (52.1%), infants (50.4%), and teens (40.6%). Resistance to two or more antibiotics varied across age groups, with toddlers (27%) leading preteens (23.1%), infants (21%), and teens (15.9%). Resistance to three or more antibiotics was low in all age groups (range 3.1-5.2%). The most common co-resistance in all age groups was ampicillin/TMP-SMZ. In conclusion, less than half of all pediatric UTIs are susceptible to all commonly used antibiotics. In some age groups, there is a significant percentage of co-resistance between the two most commonly used antibiotics (ampicillin and TMP-SMZ).

Amoxicillin/clavulanate for infections in infants and children: past, present and future.

PubMed

Klein, Jerome O

2003-08-01

Chemical synthesis of the penicillin nucleus in the 1950s made introduction of a broad array of new and important antimicrobials, including ampicillin and amoxicillin, possible. Ampicillin was introduced in 1962 in oral and parenteral forms as the first of the semisynthetic penicillins to provide increased activity against Gram-negative bacteria. Amoxicillin replaced oral ampicillin beginning in 1974 because amoxicillin resulted in higher and more prolonged serum concentrations than did equivalent doses of ampicillin. Amoxicillin/clavulanate (Augmentin) was introduced in the United States in 1984 to enhance the activity of amoxicillin by addition of the beta-lactamase inhibitor, clavulanic acid. During the past 20 years, amoxicillin/clavulanate has proven effective for a variety of pediatric infectious diseases, particularly acute otitis media (AOM). In 2001, a new pediatric formulation, high dose amoxicillin/clavulanate (Augmentin ES-600) was approved for use in the United States. The high dose preparation addressed the needs of pediatricians by providing greater amounts of amoxicillin while maintaining the same daily dose of clavulanic acid as the regular strength formulation. Doubling the dose of amoxicillin for management of recurrent and persistent AOM was recommended in 1999 by the Centers for Disease Control and Prevention because of concern about the increased incidence of nonsusceptible strains of Streptococcus pneumoniae. The original formulation combined amoxicillin/clavulanate in a 4:1 ratio and was followed by a 7:1 ratio formulation. The high dose formulation (600 mg of amoxicillin per 5 ml) provides a 14:1 ratio of amoxicillin to clavulanate. Although management of AOM will likely undergo changes in the coming years, amoxicillin is expected to remain first line therapy for AOM. For children who fail initial therapy with amoxicillin, high dose amoxicillin/clavulanate, an oral cephalosporin or parenteral ceftriaxone is recommended.

Antimicrobial Susceptibility of Udder Pathogens Isolated from Dairy Herds in the West Littoral Region of Uruguay

PubMed Central

2002-01-01

A total of 522 strains belonging to streptococci, enterococci and staphylococci isolated from sub-clinical and clinical cases of bovine mastitis from the west littoral region of Uruguay were analysed for their susceptibility to several antimicrobial agents. The susceptibility patterns were studied by agar disk diffusion methods (ADDM) and broth micro-dilution to determine the minimum inhibitory concentration (MIC). The concentration that inhibits 90% (MIC90) of the analysed strains reported in micrograms per millilitre, for Staphylococcus aureus were > 8, 8, ≤ 0.5, ≤ 4, ≤ 1, ≤ 0.5, > 64, ≤ 0.25, 0.5, ≤ 1 and ≤ 1 to penicillin, ampicillin, oxacillin, cephalotin, gentamicin, erythromycin, oxitetracycline, enrofloxacin, trimethoprim/sulfamethoxazole, neomycin, and clindamycin, respectively. Coagulase-negative staphylococci (CNS) had different values for penicillin (4) and ampicillin (2), while the other antimicrobial agents had the same MIC90 values as reported for S. aureus. The MIC90 values for streptococci were 0.12, 0.25, ≤ 4, 16, ≤ 0.25, 0.5, 0.25 for penicillin, ampicillin, cephalotin, gentamicin, erythromycin, oxytetracycline and trimethoprim-sulfamethoxazole, whereas MIC90 for enterococci were 4, 4, 4, ≤ 0.5, 2, > 8 for penicillin, ampicillin, gentamicin, erythromycin, oxytetracycline and trimethoprim-sulfamethoxazole, respectively. Of 336 strains of S. aureus, 160 (47.6%) were resistant to penicillin. For 41 CNS strains, 10 (27%) presented penicillin-resistance. All the streptococcal strains were susceptible to penicillin, while 3 (7%) of the 43 enteroccocal strains were resistant. Non significant statistical differences were found between the results obtained by ADDM and broth micro-dilution for classifying bacterial isolates as susceptible or resistant according to the National Committee of Clinical Laboratory Standards. PMID:12071114

Simultaneous pharmacodynamic analysis of the lag and bactericidal phases exhibited by beta-lactams against Escherichia coli.

PubMed Central

Li, R C

1996-01-01

Antibiotic-bacterium interactions are complex in nature. In many cases, bacterial killing does not commence immediately after the addition of an antibiotic, and a lag period is observed. Antibiotic permeation and/or the intermediate steps that exist between antibiotic-receptor binding and expression of cell death are two major possible causes for such lag period. This study was primarily designed to determine the relationship, if any, between antibiotic concentrations and the lag periods by a modeling approach. Short-term time-kill studies were conducted for amoxicillin, ampicillin, penicillin-G, oxacillin, and dicloxacillin against Escherichia coli. In conjunction with the use of a saturable rate model to describe the concentration-dependent killing process, a first-order induction (initiation) rate constant was used to characterize the delay in bacterial killing during the lag period. For all of the beta-lactams tested, parameters describing the bactericidal effect suggest that amoxicillin and ampicillin were much more potent than oxacillin and dicloxacillin. The induction rate constant estimates for both ampicillin and amoxicillin were found to relate linearly to concentrations. Nevertheless, these induction rate constant estimates were lower for penicillin-G, oxacillin, and dicloxacillin and increased nonlinearly with concentrations until an apparent plateau was observed. These findings support the hypothesis that the permeation process is potentially a rate-limiting step for the rapid bactericidal beta-lactams such as ampicillin and amoxicillin. However, as suggested by previous observations of the various morphological changes induced by beta-lactams, the contribution of the steps following antibiotic-receptor complex formation to the lag period might be significant for the less bactericidal antibiotics such as oxacillin and dicloxacillin. Findings from the present modeling approach can potentially be used to guide future bench experimentation. PMID:8891135

[Rational antimicrobial therapy in patients with purulent inflammatory diseases of maxillofacial area].

PubMed

Bogatov, B B; Denis, A G; Koliadov, N F

2015-01-01

The aim of the study was to reveal optimal antimicrobial agents in patients with purulent inflammatory diseases of maxillofacial area according to bacteriological study results. One hundred twenty-one culture samples from 32 patients aged from 21 to 68 years admitted to Nurnberg Maxillofacial Surgery Clinic. Pathogenic flora was mostly mixed with 66.9% of anaerobic germs in the majority of cases irresponsible to ampicillin (1.3%) and clindamycin (0.7%). The drugs of choice are ampicillin/sulbactam and amoxicillin/clavulanate. Bacteriological study should be included as a useful tool in treatment protocols of patients with purulent inflammatory diseases of maxillofacial area.

Degradation of ampicillin antibiotic by electrochemical processes: evaluation of antimicrobial activity of treated water.

PubMed

Vidal, Jorge; Huiliñir, Cesar; Santander, Rocío; Silva-Agredo, Javier; Torres-Palma, Ricardo A; Salazar, Ricardo

2018-05-17

Ampicillin (AMP) is an antibiotic widely used in hospitals and veterinary clinics around the world for treating infections caused by bacteria. Therefore, it is common to find traces of this antibiotic in wastewater from these entities. In this work, we studied the mineralization of this antibiotic in solution as well as the elimination of its antimicrobial activity by comparing different electrochemical advanced oxidation processes (EAOPs), namely electro-oxidation with hydrogen peroxide (EO-H 2 O 2 ), electro-Fenton (EF), and photo electro-Fenton (PEF). With PEF process, a high degradation, mineralization, and complete elimination of antimicrobial activity were achieved in 120-min electrolysis with high efficiency. In the PEF process, fast mineralization rate is caused by hydroxyl radicals (·OH) that are generated in the bulk, on the anode surface, by UV radiation, and most importantly, by the direct photolysis of complexes formed between Fe 3+ and some organic intermediates. Moreover, some products and intermediates formed during the degradation of the antibiotic Ampicillin, such as inorganic ions, carboxylic acids, and aromatic compounds, were determined by photometric and chromatographic methods. An oxidation pathway is proposed for the complete conversion to CO 2 .

Antimicrobial resistance among Escherichia coli that cause childhood community-acquired urinary tract infections in Northern Italy

PubMed Central

2011-01-01

Abstracts Background Resistance rate of Escherichia coli against antimicrobials that are commonly prescribed in pediatric urinary tract infections is currently a matter of concern. Methods The antimicrobial susceptibility patterns of uropathogenic Escherichia coli strains to the common antibimcrobials ampicillin, cotrimoxazole, coamoxyclav, ceftazidime, ceftriaxone, nitrofurantoin, and gentamycin were determined in 177 children aged from 2 to 36 months. They presented with their first symptomatic community acquired urinary tract infection at the Department of Pediatrics, San Leopoldo Mandic Hospital, Merate-Lecco. Results High rates of ampicillin (inpatients: 50%; outpatients: 52%) resistance were identified. The resistance for cotrimoxazole (inpatients: 22%; outpatients: 15%) and especially coamoxyclav (inpatients: 6%; outpatients: 10%) was less pronounced than that to ampicillin. No resistance or less than 1% of resistance was identified for ceftazidime, ceftriaxone, nitrofurantoin, and gentamycin both in inpatients and in outpatients. Conclusions Italian children affected with a community acquired urinary tract infection are initially managed orally with coamoxyclav or parenterally with ceftriaxone. The results of the present retrospective analysis support this attitude. Parenteral ceftriaxone or an aminoglycoside should be considered for patients on antimicrobial prophylaxis or recently prescribed antimicrobials. PMID:21211026

Herd-level association between antimicrobial use and antimicrobial resistance in bovine mastitis Staphylococcus aureus isolates on Canadian dairy farms.

PubMed

Saini, V; McClure, J T; Scholl, D T; DeVries, T J; Barkema, H W

2012-04-01

Surveillance of antimicrobial use and resistance is needed to manage antimicrobial resistance in bacteria. In this study, data were collected on antimicrobial use and resistance in Staphylococcus aureus (n=562), isolated from intramammary infections and (sub)clinical mastitis cases on 89 dairy farms in 4 regions of Canada [Alberta, Ontario, Québec, and the Maritime Provinces (Prince Edward Island, Nova Scotia, and New Brunswick)]. Dairy producers were asked to deposit empty drug containers into specially provided receptacles, and antimicrobial drug use rate was calculated to quantify antimicrobial use. Minimum inhibitory concentrations were determined using the Sensititer bovine mastitis plate system (TREK Diagnostic Systems Inc., Cleveland, OH), containing antimicrobials commonly used for mastitis treatment and control. Multivariable logistic regression models were built to determine herd-level risk factors of penicillin, ampicillin, pirlimycin, penicillin-novobiocin combination, tetracycline and sulfadimethoxine resistance in Staph. aureus isolates. Intramammary administration of the penicillin-novobiocin combination for dry cow therapy was associated with penicillin and ampicillin resistance [odds ratio (OR): 2.17 and 3.10, respectively]. Systemic administration of penicillin was associated with penicillin resistance (OR: 1.63). Intramammary administration of pirlimycin for lactating cow mastitis treatment was associated with pirlimycin resistance as well (OR: 2.07). Average herd parity was associated with ampicillin and tetracycline resistance (OR: 3.88 and 0.02, respectively). Average herd size was also associated with tetracycline resistance (OR: 1.02). Dairy herds in the Maritime region had higher odds of penicillin and lower odds of ampicillin resistance than dairy herds in Québec (OR: 2.18 and 0.19, respectively). Alberta dairy herds had lower odds of ampicillin and sulfadimethoxine resistance than dairy herds in Québec (OR: 0.04 and 0.08, respectively). Ontario dairy herds had lower odds of tetracycline and sulfadimethoxine resistance than dairy herds in Québec (OR: 0.05 and 0.33, respectively). Herd-level use of certain antimicrobials administered for mastitis treatment and control, such as intramammary penicillin and pirlimycin as well as systemically administered penicillin and florfenicol, was positively associated with antimicrobial resistance in bovine mastitis pathogens in the field conditions. Differences in antimicrobial resistance outcomes across 4 regions of Canada were observed. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Implementation of Reach Logistics in Support of the Department of the Army’s Transformation Policy Including a Review of Forward Surgical Team Unit Assemblage Management

DTIC Science & Technology

2003-06-01

012580983 VECURONIUM BROMIDE10S PG $142.73 4 79 6505 012695637 AMPICILLIN SOD 1GM10S PG $6.81 20 80 6505 012752568 AMPICILLIN &SULBACTAM PG $143.41 2...VI $9.70 1 61 6505 012580983 VECURONIUM BROMIDE10S PG $142.73 4 62 6505 013069504 METRONIDAZOLE TABS100 BT $4.85 2 63 6505 013306269 SODIUM CHL INJ0.9...INJ 10S PG $192.71 1 67 6505 014163228 ISOPROPYL ALCOHOL USP BT $5.15 1 68 6505 014437076 EPHEDRINE SULFATE INJ PG $17.57 2 69 6505 014437083

Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

PubMed Central

Chudobova, Dagmar; Dostalova, Simona; Blazkova, Iva; Michalek, Petr; Ruttkay-Nedecky, Branislav; Sklenar, Matej; Nejdl, Lukas; Kudr, Jiri; Gumulec, Jaromir; Tmejova, Katerina; Konecna, Marie; Vaculovicova, Marketa; Hynek, David; Masarik, Michal; Kynicky, Jindrich; Kizek, Rene; Adam, Vojtech

2014-01-01

There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. PMID:24651395

Metabolomic approach to optimizing and evaluating antibiotic treatment in the axenic culture of cyanobacterium Nostoc flagelliforme.

PubMed

Han, Pei-pei; Jia, Shi-ru; Sun, Ying; Tan, Zhi-lei; Zhong, Cheng; Dai, Yu-jie; Tan, Ning; Shen, Shi-gang

2014-09-01

The application of antibiotic treatment with assistance of metabolomic approach in axenic isolation of cyanobacterium Nostoc flagelliforme was investigated. Seven antibiotics were tested at 1-100 mg L(-1), and order of tolerance of N. flagelliforme cells was obtained as kanamycin > ampicillin, tetracycline > chloromycetin, gentamicin > spectinomycin > streptomycin. Four antibiotics were selected based on differences in antibiotic sensitivity of N. flagelliforme and associated bacteria, and their effects on N. flagelliforme cells including the changes of metabolic activity with antibiotics and the metabolic recovery after removal were assessed by a metabolomic approach based on gas chromatography-mass spectrometry combined with multivariate analysis. The results showed that antibiotic treatment had affected cell metabolism as antibiotics treated cells were metabolically distinct from control cells, but the metabolic activity would be recovered via eliminating antibiotics and the sequence of metabolic recovery time needed was spectinomycin, gentamicin > ampicillin > kanamycin. The procedures of antibiotic treatment have been accordingly optimized as a consecutive treatment starting with spectinomycin, then gentamicin, ampicillin and lastly kanamycin, and proved to be highly effective in eliminating the bacteria as examined by agar plating method and light microscope examination. Our work presented a strategy to obtain axenic culture of N. flagelliforme and provided a method for evaluating and optimizing cyanobacteria purification process through diagnosing target species cellular state.

SEM Analysis of Surface Impact on Biofilm Antibiotic Treatment.

PubMed

Gomes, Luciana Calheiros; Mergulhão, Filipe José

2017-01-01

The aim of this work was to use scanning electron microscopy (SEM) to investigate the effect of ampicillin treatment on Escherichia coli biofilms formed on two surface materials with different properties, silicone (SIL) and glass (GLA). Epifluorescence microscopy (EM) was initially used to assess biofilm formation and killing efficiency on both surfaces. This technique showed that higher bacterial colonization was obtained in the hydrophobic SIL than in the hydrophilic GLA. It has also shown that higher biofilm inactivation was attained for GLA after the antibiotic treatment (7-log reduction versus 1-log reduction for SIL). Due to its high resolution and magnification, SEM enabled a more detailed analysis of the antibiotic effect on biofilm cells, complementing the killing efficiency information obtained by EM. SEM micrographs revealed that ampicillin-treated cells have an elongated form when compared to untreated cells. Additionally, it has shown that different materials induced different levels of elongation on cells exposed to antibiotic. Biofilms formed on GLA showed a 37% higher elongation than those formed on SIL. Importantly, cell elongation was related to viability since ampicillin had a higher bactericidal effect on GLA-formed biofilms. These findings raise the possibility of using SEM for understanding the efficacy of antimicrobial treatments by observation of biofilm morphology.

Celecoxib Sensitizes Staphylococcus aureus to Antibiotics in Macrophages by Modulating SIRT1

PubMed Central

Annamanedi, Madhavi; Kalle, Arunasree M.

2014-01-01

We have previously shown that celecoxib in combination with an antibiotic, increase the bacterial sensitivity to antibiotics. However, the underlying molecular mechanism remained elusive. Efficacy of the combinatorial treatment of celecoxib and ampicillin in vitro was evaluated on macrophage-phagocytosed S aureus. To elucidate the mechanism, signaling pathway of infection and inflammation involving TLR2, JNK, SIRT1 and NF-κB was studied by FACS, Western blot, ELISA and activity assays. Combinatorial treatment of ampicillin and celecoxib reduced the bacterial load in the macrophages. Further studies clearly suggested the activation of the master regulator of oxidative stress and inflammation SIRT1,, by celecoxib when used alone and/or in combination with ampicillin. Also, the results indicated that celecoxib inhibited JNK phosphorylation thereby stabilizing and activating SIRT1 protein that inhibited the COX-2 gene transcription with a significant decrease in the levels of protein inflammatory cytokines like IL-6, MIP-1α and IL-1β via inhibition of NF-κB. SIRT1 activation by celecoxib also resulted in increase of catalase and peroxidase activity with a decrease in Nitric oxide levels. In conclusion, we demonstrate a novel role of celecoxib in controlling inflammation as an enhancer of antibiotic activity against bacteria by modulating SIRT1. PMID:24950067

Celecoxib sensitizes Staphylococcus aureus to antibiotics in macrophages by modulating SIRT1.

PubMed

Annamanedi, Madhavi; Kalle, Arunasree M

2014-01-01

We have previously shown that celecoxib in combination with an antibiotic, increase the bacterial sensitivity to antibiotics. However, the underlying molecular mechanism remained elusive. Efficacy of the combinatorial treatment of celecoxib and ampicillin in vitro was evaluated on macrophage-phagocytosed S. aureus. To elucidate the mechanism, signaling pathway of infection and inflammation involving TLR2, JNK, SIRT1 and NF-κB was studied by FACS, Western blot, ELISA and activity assays. Combinatorial treatment of ampicillin and celecoxib reduced the bacterial load in the macrophages. Further studies clearly suggested the activation of the master regulator of oxidative stress and inflammation SIRT1, by celecoxib when used alone and/or in combination with ampicillin. Also, the results indicated that celecoxib inhibited JNK phosphorylation thereby stabilizing and activating SIRT1 protein that inhibited the COX-2 gene transcription with a significant decrease in the levels of protein inflammatory cytokines like IL-6, MIP-1α and IL-1β via inhibition of NF-κB. SIRT1 activation by celecoxib also resulted in increase of catalase and peroxidase activity with a decrease in Nitric oxide levels. In conclusion, we demonstrate a novel role of celecoxib in controlling inflammation as an enhancer of antibiotic activity against bacteria by modulating SIRT1.

Plasmid Frequency Fluctuations in Bacterial Populations from Chemically Stressed Soil Communities

PubMed Central

Wickham, Gene S.; Atlas, Ronald M.

1988-01-01

The frequency of plasmids in chemically stressed bacterial populations was investigated by individually adding various concentration of kanamycin, ampicillin, and mercuric chloride to soil samples. Viable bacterial populations were enumerated, soil respiration was monitored for up to 6 weeks as an indicator of physiological stress, and bacterial isolates from stressed and control soils were screened for the presence of plasmids. Low levels of the chemical stress factors did not for the most part significantly alter population viability, soil respiration, or plasmid frequency. Exposure to high stress levels of mercury and ampicillin, however, resulted in altered numbers of viable organisms, soil respiration, and plasmid frequency. Plasmid frequency increased in response to ampicillin exposure but was not significantly changed after exposure to kanamycin. In mercuric chloride-stressed soils, there was a decrease in plasmid frequency despite an increase in overall mercury resistance of the isolates, suggesting that mercury resistance in these populations is largely, if not completely, chromosome encoded. Chemical stress did not cause an increase in plasmid-mediated multiple resistance. A genetic response (change in plasmid frequency) was not found unless a physiological (phenotypic) response (change in viable cells and respiratory activity) was also observed. The results indicate that a change in plasmid frequency is dependent on both the amount and type of chemical stress. PMID:16347730

Antibiotic therapy of fulminant E. coli K1 sepsis in infant rabbits.

PubMed

Law, B J; Rettig, P J; Marks, M I

1984-04-01

A model of overwhelming E. coli K1 sepsis and early meningitis was developed in infant rabbits and used to compare clinical and bacteriologic efficacy of ampicillin, moxalactam, cephalothin and chloramphenicol. Intraperitoneal injection of 10(7) E. coli K1 into 1- or 2-wk-old rabbits produced a rapidly progressive infection which, if left untreated, produced bacteremia in 100% of animals, meningitis in 78%, and mortality in 100%. Therapy was initiated 4 h after ip infection at which time mean bacterial concentration (log10 CFU/ml) ranged from 4.4-4.8 in the blood and from 1.8-2.3 in the cerebral spinal fluid (CSF). Pre-treatment frequency of bacteremia (100%) and meningitis (17-23%) was similar for all experimental groups. Antibiotic concentrations in blood and CSF 2 h after a dose exceeded the E. coli minimum inhibitory concentration with the exception of CSF cephalothin, which was undetectable. Moxalactam, ampicillin, and chloramphenicol significantly reduced the incidence of bacteremia and meningitis relative to cephalothin or saline controls (P less than 0.02). Mortality rates among the former three groups were high (64-82%) but significantly less than in saline or cephalothin-treated rabbits (100%). In this neonatal model of fulminant sepsis with early meningitis, moxalactam provided no therapeutic advantage over ampicillin or chloramphenicol.

Antimicrobial susceptibility against penicillin, ampicillin and vancomycin of viridans group Streptococcus in oral microbiota of patients at risk of infective endocarditis.

PubMed

Süzük, Serap; Kaşkatepe, Banu; Çetin, Mustafa

2016-09-01

The viridans group Streptococci (VGS) are most abundant in the mouth; in some instances they might emerge as pathogens particularly in infective endocarditis (IE). In this study, we aimed to define and determine the susceptibility against antibiotics of VGS that are members of the oral microbiota of patients exhibiting a risk of developing IE. Forty-nine patients at risk of infective endocarditis were included in the study. Identification of the bacteria was performed using API STREP (bioMérieux, France). Gradient test strips (E-Test, France) were used to determine MIC of the bacteria against penicillin, ampicillin, and vancomycin. The distribution of the isolated VGS groups was determined as follows: Streptococcus mitis 32.6% and anginosus group - 32.6%, S. sanguinis group - 16.3%, S. mutans group - 12.2%, and S. salivarius group - 6.1%. The rates of resistance and reduced sensitivity of the isolates for penicillin and ampicillin were determined at 61.2% and 55.1%, respectively. However, all isolates were found to be susceptible to vancomycin. We conclude that the antimicrobial resistance of VGS should be determined on a regular basis locally, and decisions on therapeutic and prophylactic interventions should be given taking this resistance into consideration.

Co-diversification of Enterococcus faecium Core Genomes and PBP5: Evidences of pbp5 Horizontal Transfer

PubMed Central

Novais, Carla; Tedim, Ana P.; Lanza, Val F.; Freitas, Ana R.; Silveira, Eduarda; Escada, Ricardo; Roberts, Adam P.; Al-Haroni, Mohammed; Baquero, Fernando; Peixe, Luísa; Coque, Teresa M.

2016-01-01

Ampicillin resistance has greatly contributed to the recent dramatic increase of a cluster of human adapted Enterococcus faecium lineages (ST17, ST18, and ST78) in hospital-based infections. Changes in the chromosomal pbp5 gene have been associated with different levels of ampicillin susceptibility, leading to protein variants (designated as PBP5 C-types to keep the nomenclature used in previous works) with diverse degrees of reduction in penicillin affinity. Our goal was to use a comparative genomics approach to evaluate the relationship between the diversity of PBP5 among E. faecium isolates of different phylogenomic groups as well as to assess the pbp5 transferability among isolates of disparate clonal lineages. The analyses of 78 selected E. faecium strains as well as published E. faecium genomes, suggested that the diversity of pbp5 mirrors the phylogenomic diversification of E. faecium. The presence of identical PBP5 C-types as well as similar pbp5 genetic environments in different E. faecium lineages and clones from quite different geographical and environmental origin was also documented and would indicate their horizontal gene transfer among E. faecium populations. This was supported by experimental assays showing transfer of large (≈180–280 kb) chromosomal genetic platforms containing pbp5 alleles, ponA (transglycosilase) and other metabolic and adaptive features, from E. faecium donor isolates to suitable E. faecium recipient strains. Mutation profile analysis of PBP5 from available genomes and strains from this study suggests that the spread of PBP5 C-types might have occurred even in the absence of a significant ampicillin resistance phenotype. In summary, genetic platforms containing pbp5 sequences were stably maintained in particular E. faecium lineages, but were also able to be transferred among E. faecium clones of different origins, emphasizing the growing risk of further spread of ampicillin resistance in this nosocomial pathogen. PMID:27766095

Evaluation of affinity and pseudo-affinity adsorption processes for penicillin acylase purification.

PubMed

Fonseca, L P; Cabral, J M

1996-01-01

Affinity ligand (6-Aminopenicillanic acid, Amoxycillin, Ampicillin, Benzylpenicillin and 4-Phenylbutylanzine) of penicillin acylase (EC 3.5.1.11) were attached to hydrophilic gels like Sepharose 4B-CNBr and Minileak 'medium'. Ampicillin and 4-Phenylbutylamine were the affinity ligands that presented the higher concentrations attached to both gels. Penicillin acylase adsorption on these affinity gels was mainly dependent on the activated group of the gel, the affinity ligand attached and the experimental conditions of enzyme adsorption. Under affinity conditions only the ligands Amoxycillin, Ampicillin and 4-Phenylbutylamine, immobilized on Minileak, adsorbed the enzyme from osmotic shock extracts at different pH values. These affinity ligand systems were characterized by low adsorption capacities of penicillin acylase activity (1.2-2.1 IU mL-1 gel) and specific activity (1.5-2.9 IU mg-1 prot). Under pseudo-affinity conditions all the ligands attached both activated to gels (Sepharose 4B-CNBr and Minileak) adsorbed the enzyme. The affinity gels were characterized by higher values of adsorption capacity (3.7 and 55.6 IU mL-1 gel) and adsorbed specific activity (2.0 and 6.1 IU mg-1 prot) than those observed under affinity conditions. The space arm of Minileak gel, shown to be fundamental to enzyme adsorption under affinity conditions, preferentially adsorbed proteins in relation to the enzyme under pseudo-affinity conditions. However, this effect was partially minimized when the gel was derivatized by the affinity ligands at concentrations higher than 6 mumol mL-1 gel. Ampicillin was the affinity ligand that presented the best results for specific adsorption of penicillin acylase under affinity and pseudo-affinity adsorption processes. The Sepharose 4B-CNBr derivatized gel also presented a good adsorption capacity of enzyme activity (26.8 IU mL-1 gel) under pseudo-affinity adsorption processes.

Overcoming resistance to beta-lactamase inhibitors: comparing sulbactam to novel inhibitors against clavulanate resistant SHV enzymes with substitutions at Ambler position 244.

PubMed

Thomson, Jodi M; Distler, Anne M; Bonomo, Robert A

2007-10-09

Amino acid changes at Ambler position R244 in class A TEM and SHV beta-lactamases confer resistance to ampicillin/clavulanate, a beta-lactam/beta-lactamase inhibitor combination used to treat serious infections. To gain a deeper understanding of this resistance phenotype, we investigated the activities of sulbactam and two novel penem beta-lactamase inhibitors with sp2 hybridized C3 carboxylates and bicyclic R1 side chains against a library of SHV beta-lactamase variants at the 244 position. Compared to SHV-1 expressed in Escherichia coli, all 19 R244 variants exhibited increased susceptibility to ampicillin/sulbactam, an important difference compared to ampicillin/clavulanate. Kinetic analyses of SHV-1 and three SHV R244 (-S, -Q, and -L) variants revealed the Ki for sulbactam was significantly elevated for the R244 variants, but the partition ratios, kcat/kinact, were markedly reduced (13 000 -->

influence of TEM-1 beta-lactamase on the pharmacodynamic activity of simulated total versus free-drug serum concentrations of cefditoren (400 milligrams) versus amoxicillin-clavulanic acid (2,000/125 milligrams) against Haemophilus influenzae strains exhibiting an N526K mutation in the ftsI gene.

PubMed

Torrico, M; Aguilar, L; González, N; Giménez, M J; Echeverría, O; Cafini, F; Sevillano, D; Alou, L; Coronel, P; Prieto, J

2007-10-01

The aim of this study was to explore bactericidal activity of total and free serum simulated concentrations after the oral administration of cefditoren (400 mg, twice daily [bid]) versus the oral administration of amoxicillin-clavulanic acid extended release formulation (2,000/125 mg bid) against Haemophilus influenzae. A computerized pharmacodynamic simulation was performed, and colony counts and beta-lactamase activity were determined over 48 h. Three strains were used: ampicillin-susceptible, beta-lactamase-negative ampicillin-resistant (BLNAR) (also resistant to amoxicillin-clavulanic acid) and beta-lactamase-positive amoxicillin-clavulanic acid-resistant (BLPACR) strains, with cefditoren MICs of < or =0.12 microg/ml and amoxicillin-clavulanic acid MICs of 2, 8, and 8 microg/ml, respectively. Against the ampicillin-susceptible and BLNAR strains, bactericidal activity (> or =3 log(10) reduction) was obtained from 6 h on with either total and free cefditoren or amoxicillin-clavulanic acid. Against the BLPACR strain, free cefditoren showed bactericidal activity from 8 h on. In amoxicillin-clavulanic acid simulations the increase in colony counts from 4 h on occurred in parallel with the increase in beta-lactamase activity for the BLPACR strain. Since both BLNAR and BLPACR strains exhibited the same MIC, this was due to the significantly lower (P < or = 0.012) amoxicillin concentrations from 4 h on in simulations with beta-lactamase positive versus negative strains, thus decreasing the time above MIC (T>MIC). From a pharmacodynamic point of view, the theoretical amoxicillin T>MIC against strains with elevated ampicillin/amoxicillin-clavulanic acid MICs should be considered with caution since the presence of beta-lactamase inactivates the antibiotic, thus rendering inaccurate theoretical calculations. The experimental bactericidal activity of cefditoren is maintained over the dosing interval regardless of the presence of a mutation in the ftsI gene or beta-lactamase production.

Fate of classical faecal bacterial markers and ampicillin-resistant bacteria in agricultural soils under Mediterranean climate after urban sludge amendment.

PubMed

Gondim-Porto, Clarissa; Platero, Leticia; Nadal, Ignacio; Navarro-García, Federico

2016-09-15

The use of sewage sludge or biosolids as agricultural amendments may pose environmental and human health risks related to pathogen or antibiotic-resistant microorganism transmission from soils to vegetables or to water through runoff. Since the survival of those microorganisms in amended soils has been poorly studied under Mediterranean climatic conditions, we followed the variation of soil fecal bacterial markers and ampicillin-resistant bacteria for two years with samplings every four months in a split block design with three replica in a crop soil where two different types of biosolids (aerobically or anaerobically digested) at three doses (low, 40; intermediate, 80; and high, 160Mg·ha(-1)) were applied. Low amounts of biosolids produced similar decay rates of coliform populations than in control soil (-0.19 and -0.27log10CFUs·g(-1)drysoilmonth(-1) versus -0.22) while in the case of intermediate and high doses were close to zero and their populations remained 24months later in the range of 4-5log10CFUs·g(-1)ds. Enterococci populations decayed at different rates when using aerobic than anaerobic biosolids although high doses had higher rates than control (-0.09 and -0.13log10CFUs·g(-1)dsmonth(-1) for aerobic and anaerobic, respectively, vs -0.07). At the end of the experiment, counts in high aerobic and low and intermediate anaerobic plots were 1 log10 higher than in control (4.21, 4.03, 4.2 and 3.11log10CFUs·g(-1) ds, respectively). Biosolid application increased the number of Clostridium spores in all plots at least 1 log10 with respect to control with a different dynamic of decay for low and intermediate doses of aerobic and anaerobic sludge. Ampicillin-resistant bacteria increased in amended soils 4months after amendment and remained at least 1 log10 higher 24months later, especially in aerobic and low and intermediate anaerobic plots due to small rates of decay (in the range of -0.001 to -0.008log10CFUs·g(-1)dsmonth(-1) vs -0.016 for control). Aerobic plots had relative populations of ampicillin-resistant bacteria higher than anaerobic plots with different positive trends. Dose (22%) and time (13%) explained most of the variation of the bacterial populations. Dynamics of fecal markers did not correlate with ampicillin-resistant bacteria thus making necessary to evaluate specifically this trait to avoid possible risks for human and environmental health. Copyright © 2016 Elsevier B.V. All rights reserved.

Interstitial nephritis

MedlinePlus

... medicines such as acetaminophen (Tylenol), aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs). This is called analgesic nephropathy . Side effect of certain antibiotics such as penicillin, ampicillin, methicillin, and sulfonamide medicines. ...

Variation in Antibiotic Susceptibility of Uropathogens by Age among Ambulatory Pediatric Patients

PubMed Central

Quach, Yennie; Bearden, David T.; Smith, David H.; Sharp, Susan E.; Guzman-Cottrill, Judith A.

2013-01-01

We compared uropathogen antibiotic susceptibility across age groups of ambulatory pediatric patients. For Escherichia coli (n=5,099) and other Gram-negative rods (n=626), significant differences (p<0.05) existed across age groups for ampicillin, cefazolin, and trimethoprim/sulfamethoxazole susceptibility. In E. coli, differences in trimethoprim/sulfamethoxazole susceptibility varied from 79% in children under 2 to 88% in ages 16–18 (p<0.001) while ampicillin susceptibility varied from 30% in children under 2 to 53% in ages 2–5 (p=0.015). Uropathogen susceptibility to common urinary anti-infectives may be lower in the youngest children. Further investigation into these differences is needed to facilitate appropriate and prudent treatment of urinary tract infections. PMID:24091131

Fluorogenic pH-sensitive polydiacetylene (PDA) liposomes as a drug carrier.

PubMed

Won, Sang Ho; Lee, Jong Uk; Sim, Sang Jun

2013-06-01

A crucial issue for current liposomal carriers in clinical applications is the sustained-release property of the encapsulated drugs. We have developed novel fluorogenic pH-sensitive polymerized liposomes composed of polydiacetylene (PDA) lipids and other types of lipids. Unilamellar liposomes containing 10,12-pentacosadiynoic acid (PCDA), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and N-palmitoyl homocysteine (PHC) were loaded with ampicillin. These liposomes fused to each other rapidly when the medium pH was lowered from 7 to 4. The polymerized liposomes were characterized in terms of particle size distribution. The liposome size increased approximately 20-fold from 110.0 +/- 19.3 nm to 2046.7 +/- 487.4 nm as the pH was lowered. Cross-linking of the diacetylene lipids prevents drug leakage and the encapsulated drug can be instantaneously released at acidic pH condition. The ampicillin was nearly completely released (74.4 +/- 3.9%) from liposomes within 4 h under acidic pH conditions and the released amounts of ampicillin were analyzed by HPLC. Finally, the therapeutic effect was observed by the appearance of plaques on a lawn of E. coli, and fluorescent images of the PDA liposomes were taken from the plaques for drug release monitoring. As a result, this research demonstrates that such novel pH-sensitive polymerized liposomes have great prospects as a drug carrier.

KINETICS OF THE ACTION OF AMPICILLIN ON ESCHERICHIA COLI

PubMed Central

Seligman, Stephen J.; Hewitt, William L.

1963-01-01

Seligman, Stephen J. (University of California, Los Angeles) and William L. Hewitt. Kinetics of the action of ampicillin on Escherichia coli. J. Bacteriol. 85:1160–1164. 1963.—The curve of the number of viable Escherichia coli after exposure to ampicillin can be divided into three phases: a lag phase, a rapid bactericidal phase, and a slow bactericidal phase. Some of the variables affecting the magnitude of the first two of these phases were investigated. Progressive lowering of drug concentration resulted in prolongation of the lag phase and decrease in slope and extent of the rapid bactericidal phase. The production of elongated gram-negative forms and the emergence of a mutant with increased penicillinase activity complicated interpretation of the lower dose curves. With sufficient drug concentration, the length of the lag phase and the slope of the rapid bactericidal curve were independent of the size of inoculum up to 108 organisms. Varying pH revealed that maximal activity, as measured by the shortest lag phase and steepest slope of the rapid bactericidal phase, was present at slightly acid pH levels. Increasing pH resulted principally in prolongation of lag phase. With greater acidity, decrease in slope of the rapid bactericidal phase was more prominent. Cultures studied under conditions of lessened metabolic activity exhibited prolonged lag phase and decreased slope and extent of rapid bactericidal phase. PMID:14044010

Modeling cooperating micro-organisms in antibiotic environment.

PubMed

Book, Gilad; Ingham, Colin; Ariel, Gil

2017-01-01

Recent experiments with the bacteria Paenibacillus vortex reveal a remarkable strategy enabling it to cope with antibiotics by cooperating with a different bacterium-Escherichia coli. While P. vortex is a highly effective swarmer, it is sensitive to the antibiotic ampicillin. On the other hand, E. coli can degrade ampicillin but is non-motile when grown on high agar percentages. The two bacterial species form a shared colony in which E. coli is transported by P. vortex and E. coli detoxifies the ampicillin. The paper presents a simplified model, consisting of coupled reaction-diffusion equations, describing the development of ring patterns in the shared colony. Our results demonstrate some of the possible cooperative movement strategies bacteria utilize in order to survive harsh conditions. In addition, we explore the behavior of mixed colonies under new conditions such as antibiotic gradients, synchronization between colonies and possible dynamics of a 3-species system including P. vortex, E. coli and a carbon producing algae that provides nutrients under illuminated, nutrient poor conditions. The derived model was able to simulate an asymmetric relationship between two or three micro-organisms where cooperation is required for survival. Computationally, in order to avoid numerical artifacts due to symmetries within the discretizing grid, the model was solved using a second order Vectorizable Random Lattices method, which is developed as a finite volume scheme on a random grid.

Incidence of rash after amoxicillin treatment in children with infectious mononucleosis.

PubMed

Chovel-Sella, Aluma; Ben Tov, Amir; Lahav, Einat; Mor, Orna; Rudich, Hagit; Paret, Gideon; Reif, Shimon

2013-05-01

"Ampicillin rash," a phenomenon unique to patients with Epstein-Barr virus acute infectious mononucleosis (AIM) treated with ampicillin, was first reported in the 1960s. The incidence was estimated as being between 80% and 100%, and the figures have not been reviewed since those first accounts. We sought to establish the current incidence of rash associated with antibiotic treatment among children with AIM. A retrospective study of all hospitalized children diagnosed as having AIM based upon positive Epstein-Barr virus serology in 2 pediatric tertiary medical centers in Israel. Of the 238 children who met the study entry criteria during the study period, 173 were treated with antibiotics. Fifty-seven (32.9%) of the subjects treated with antibiotics had a rash during their illness compared with 15 (23.1%) in untreated patients (P = .156; not significant). Amoxicillin was associated with the highest incidence of antibiotic-induced rash occurrence (29.5%, 95% confidence interval: 18.52-42.57), but significantly lower than the 90% rate reported for ampicillin in past studies. Age, gender, ethnicity, and atopic or allergic history were not associated with the development of rash after antibiotic exposure. Among the laboratory data, only increased white blood cell counts were more prevalent among subjects who did not develop an antibiotic-induced rash. The incidence of rash in pediatric patients with AIM after treatment with the current oral aminopenicillin (amoxicillin) is much lower than originally reported.

Modeling cooperating micro-organisms in antibiotic environment

PubMed Central

Book, Gilad; Ingham, Colin; Ariel, Gil

2017-01-01

Recent experiments with the bacteria Paenibacillus vortex reveal a remarkable strategy enabling it to cope with antibiotics by cooperating with a different bacterium—Escherichia coli. While P. vortex is a highly effective swarmer, it is sensitive to the antibiotic ampicillin. On the other hand, E. coli can degrade ampicillin but is non-motile when grown on high agar percentages. The two bacterial species form a shared colony in which E. coli is transported by P. vortex and E. coli detoxifies the ampicillin. The paper presents a simplified model, consisting of coupled reaction-diffusion equations, describing the development of ring patterns in the shared colony. Our results demonstrate some of the possible cooperative movement strategies bacteria utilize in order to survive harsh conditions. In addition, we explore the behavior of mixed colonies under new conditions such as antibiotic gradients, synchronization between colonies and possible dynamics of a 3-species system including P. vortex, E. coli and a carbon producing algae that provides nutrients under illuminated, nutrient poor conditions. The derived model was able to simulate an asymmetric relationship between two or three micro-organisms where cooperation is required for survival. Computationally, in order to avoid numerical artifacts due to symmetries within the discretizing grid, the model was solved using a second order Vectorizable Random Lattices method, which is developed as a finite volume scheme on a random grid. PMID:29284016

Antimicrobial activity of berberine alone and in combination with ampicillin or oxacillin against methicillin-resistant Staphylococcus aureus.

PubMed

Yu, Hyeon-Hee; Kim, Kang-Ju; Cha, Jeong-Dan; Kim, Hae-Kyoung; Lee, Young-Eun; Choi, Na-Young; You, Yong-Ouk

2005-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) bacteria have been responsible for substantial morbidity and mortality in hospitals because they usually have multidrug resistance. Some natural products are candidates as new antibiotic substances. In the present study, we investigated the antimicrobial activity of berberine, the main antibacterial substance of Coptidis rhizoma (Coptis chinensis Franch) and Phellodendri cortex (Phellodendron amurense Ruprecht), against clinical isolates of MRSA, and the effects of berberine on the adhesion to MRSA and intracellular invasion into human gingival fibroblasts (HGFs). Berberine showed antimicrobial activity against all tested strains of MRSA. Minimum inhibition concentrations (MICs) of berberine against MRSA ranged from 32 to 128 microg/mL. Ninety percent inhibition of MRSA was obtained with 64 microg/mL or less of berberine. In the checkerboard dilution test, berberine markedly lowered the MICs of ampicillin and oxacillin against MRSA. An additive effect was found between berberine and ampicillin, and a synergistic effect was found between berberine and oxacillin against MRSA. In the presence of 1-50 microg/mL berberine, MRSA adhesion and intracellular invasion were notably decreased compared with the vehicle-treated control group. These results suggest that berberine may have antimicrobial activity and the potential to restore the effectiveness of beta-lactam antibiotics against MRSA, and inhibit the MRSA adhesion and intracellular invasion in HGFs.

Thermo-and pH-sensitive hydrogel membranes composed of poly(N-isopropylacrylamide)-hyaluronan for biomedical applications: Influence of hyaluronan incorporation on the membrane properties.

PubMed

Kamoun, Elbadawy A; Fahmy, Alaa; Taha, Tarek H; El-Fakharany, Esmail M; Makram, Mohamed; Soliman, Hesham M A; Shehata, Hassan

2018-01-01

Interpenetrating hydrogel membranes consisting of pH-sensitive hyaluronan (HA) and thermo-sensitive poly(N-isopropylacrylamide) (PNIPAAM) were synthesized using redox polymerization, followed by N,N-methylenebisacrylamide (BIS) and epichlorohydrin (EPI) were added as chemical crosslinkers. The interaction between membrane compositions has been characterized by FTIR spectroscopy and discussed intensively. The result indicates that HA incorporation in membranes increase the gel fraction, swelling uptake, and the flexibility/elasticity of crosslinked membranes, however it reduced oppositely the mechanical elongation of membranes. PNIPAAm-HA hydrogels responded to both temperature and pH changes and the stimuli-responsiveness was reversible. However, in vitro bioevaluation results revealed that the released ampicillin during the burst release time was sharply influenced and increased with increasing HA contents in membranes; afterwards it became sustainable. Whereas, high HA contents in hydrogels unexpectedly impacted negatively on the cells viability, owing to the viscosity of cell culture media changed. A big resistance was observed against microbial growth of Staphylococcus aureus, Salmonella typhi, and Candida albicans in case of pure PNIPAAm hydrogel membranes without HA or ampicillin. However, HA incorporation or the loaded ampicillin in membranes showed unexpected easily microbial growth. The fast release performance with dual pH-thermo-sensitive hydrogels were suggested as promising materials for quick drug carrier in the biomedical field. Copyright © 2017 Elsevier B.V. All rights reserved.

Isolation and Characterization of a Lytic Bacteriophage (vB_PmiS-TH) and Its Application in Combination with Ampicillin against Planktonic and Biofilm Forms of Proteus mirabilis Isolated from Urinary Tract Infection.

PubMed

Yazdi, Mahsa; Bouzari, Majid; Ghaemi, Ezzat Allah

2018-01-01

Proteus mirabilis is one of the most common causes of urinary tract infection (UTI), particularly in patients undergoing long-term catheterization. Phage vB_PmiS-TH was isolated from wastewater with high lytic activity against P. mirabilis (TH) isolated from UTI. The phage had rapid adsorption, a large burst size (∼260 PFU per infected cell), and high stability at a wide range of temperatures and pH values. As analyzed by transmission electron microscopy, phage vB_PmiS-TH had an icosahedral head of ∼87 × 62 nm with a noncontractile tail about 137 nm in length and 11 nm in width. It belongs to the family Siphoviridae. Combination of the phage vB_PmiS-TH with ampicillin had a higher removal activity against planktonic cells of P. mirabilis (TH) than the phage or the antibiotic alone. Combination of the phage at a multiplicity of infection of 100 with a high dose of ampicillin (246 µg/mL) showed the highest biofilm removal activity after 24 h. This study demonstrates that using a combination of phage and antibiotic could be significantly more effective against planktonic and biofilm forms of P. mirabilis (TH). © 2018 S. Karger AG, Basel.

[Multiresistant Pseudomonas spp. in vitro susceptibility to a combination of two antibiotics].

PubMed

Pliego-Castañeda, Q F B Amanda; Yánez-Viguri, Jorge Antonio; López-Valle, Tiburcio

2005-01-01

In vitro antibiotic combination testing would guide therapy selection in patients severely affected by multi-drug resistant Pseudomonas. In vitro, a two-antibiotic combination susceptible against multi-drug resistant Pseudomonas isolated at the Laboratorio Clínico of the Hospital de Oncología, Centro Médico Nacional Siglo XXI in Mexico City were analyzed to determine which antibiotic combination showed the best bactericidal activity. During 10 months, 30 multi-drug resistant Pseudomonas strains were tested. An automated method was used, including a diluting solution with a well-known concentration of a second antibiotic. Quality controls recommended by the NCCLS were used. Pseudomonas aeruginosa ATCC 27853; Escherichia coli ATCC 25922; and Escherichia coli ATCC 35218. Combinations were betalactamics-aminoglycosides; carbapenemis-amikacin; fluoroquinolones-cefepime; and ciprofloxacin-ampicillin. Ampicillin-ciprofloxacin combination was bactericidal against 100% of the isolates. Cefazolin, cefixime and ticarcillin with amikacin: <50%; aztreonam, cefoxilin, cefuroxime, cefotaxime, ceftazidime and piperacillin with amikacin: 50-60%; cefepime with gentamicin: 76%; cefepime with amikacin: 86%; imipenem and meropenem with amikacin: 70% and 76%; cefepime with ciprofloxacin: 83%; cefepime with levofloxacin: 73%. In vitro antibiotic combination susceptibilities against multi-drug resistant bacteria would be the only way to guide clinicians to select the best therapy in severe infections. We found that the ampicillin-ciprofloxacin combination showed the best in vitro effect against multi-drug resistant Pseudomonas.

Long-acting chloramphenicol versus intravenous ampicillin for treatment of bacterial meningitis.

PubMed

Pécoul, B; Varaine, F; Keita, M; Soga, G; Djibo, A; Soula, G; Abdou, A; Etienne, J; Rey, M

1991-10-05

In most developing countries, bacterial meningitis (BM) is associated with a high case-fatality rate. The search for a simple, convenient, and inexpensive antibiotic treatment remains a priority. In this study, a non-blinded, multicentre, randomised clinical trial of 528 cases of BM was done in two hospitals in Mali and Niger, between March, 1989, and May, 1990, to see whether a double injection of long-acting chloramphenicol (on admission to hospital and 48 h later) is as effective as a course of intravenous ampicillin (8 days, 4 times a day). The cumulative case-fatality rate on day 4 (principal end-point) among the chloramphenicol (254 patients) and ampicillin (274) groups were, respectively, 28% and 24.5% (relative risk 1.14, 95% confidence interval 0.86-1.52). No outbreak occurred during the study period. The hospital case-fatality rate was 33.1%. Main risk factors for death were associated with clinical condition on admission--ie, altered consciousness, convulsions, or dehydration. The case-fatality rates were 13% (21/161) for Neisseria meningitidis, 36.1% (48/133) for Haemophilus influenzae, and 67% (77/115) for Streptococcus pneumoniae. In a multiple logistic regression model, controlling for the differential distribution of potential risk factors (including bacterial species), there was no difference between treatment groups. Our findings suggest that long-acting chloramphenicol is a useful first-line presumptive treatment for BM in high-incidence countries.

Plasmid incidence in bacteria from deep subsurface sediments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fredrickson, J.K.; Hicks, R.J.; Li, S.W.

Bacteria were isolated from deep terrestrial subsurface sediments underlying the coastal plain of South Carolina. A total of 163 isolates from deep sediments, surface soil, and return drill muds were examined for plasmid DNA content and resistance to the antibiotics penicillin, ampicillin, carbenicillin, streptomycin, kanamycin, and tetracycline. MICs of Cu{sup 2+}, Cr{sup 3+}, and Hg{sup 2+} for each isolate were also determined. The overall frequency of plasmid occurrence in the subsurface bacteria was 33%. Resistance was most frequent to penicillin (70% of all isolates), ampicillin (49%), and carbenicillin (32%) and was concluded to be related to the concentrations of themore » individual antibiotics in the disks used for assaying resistance and to the production of low levels of {beta}-lactamase. The frequencies of resistance to penicillin and ampicillin were significantly greater for isolates bearing plasmids than for plasmidless isolates; however, resistance was not transferable to penicillin-sensitive Escherichia coli. Hybridization of subsurface bacterial plasmids and chromosomal DNA with a whole-TOL-plasmid (pWWO) probe revealed some homology of subsurface bacterial plasmid and chromosomal DNAs, indicating a potential for those bacterial to harbor catabolic genes on plasmids or chromosomes. The incidences of antibiotic resistance and MICs of metals for subsurface bacteria were significantly different from those drill mud bacteria, ruling out the possibility that bacteria from sediments were derived from drill muds.« less

Susceptibility of Haemophilus influenzae to chloramphenicol and eight beta-lactam antibiotics.

PubMed Central

Thirumoorthi, M C; Kobos, D M; Dajani, A S

1981-01-01

We examined the minimal inhibitory concentrations and minimal bactericidal concentrations of chloramphenicol, ampicillin, ticarcillin, cefamandole, cefazolin, cefoxitin, cefotaxime, ceforanide, and moxalactam for 100 isolates of Haemophilus influenzae, 25 of which produced beta-lactamase. Susceptibility was not influenced by the capsular characteristic of the organism. The mean minimal inhibitory concentrations of cefamandole, ticarcillin, and ampicillin for beta-lactamase-producing strains were 3-, 120-, and 400-fold higher than their respective mean minimal inhibitory concentrations for beta-lactamase-negative strains. No such difference was noted for the other antibiotics. We performed time-kill curve studies, using chloramphenicol, ampicillin, cefamandole, cefotaxime, and moxalactam with two concentrations of the antimicrobial agents (4 or 20 times the minimal inhibitory concentrations) and two inoculum sizes (10(4) or 10(6) colony-forming units per ml). The inoculum size had no appreciable effect on the rate of killing of beta-lactamase-negative strains. The rates at which beta-lactamase-producing strains were killed by chloramphenicol, cefotaxime, and moxalactam was not influenced by the inoculum size. Whereas cefamandole in high concentrations was able to kill at 10(6) colony-forming units/ml of inoculum, it had only a temporary inhibiting effect at low drug concentrations. Methicillin and the beta-lactamase inhibitor CP-45,899 were able to neutralize the inactivation of cefamandole by a large inoculum of beta-lactamase-producing H. influenzae. PMID:6974541

21 CFR 520.90e - Ampicillin trihydrate soluble powder.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Indications for use. Oral treatment of porcine colibacillosis (Escherichia coli) and salmonellosis (Salmonella... Pasteurella multocida, Staphylococcus spp., Streptococcus spp., and Salmonella spp. (3) Limitations. For use...

21 CFR 520.90e - Ampicillin trihydrate soluble powder.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Indications for use. Oral treatment of porcine colibacillosis (Escherichia coli) and salmonellosis (Salmonella... Pasteurella multocida, Staphylococcus spp., Streptococcus spp., and Salmonella spp. (3) Limitations. For use...

Osteomyelitis Caused by Moraxella osloensis

PubMed Central

Sugarman, Barrett; Clarridge, Jill

1982-01-01

Moraxella osloensis osteomyelitis of the femur developed in a paraplegic man. He responded to treatment with oral ampicillin. Disease in humans caused by this unusual clinical isolate is reviewed. PMID:7107844

Anaerobic Infections

MedlinePlus

... doctor may treat it with intravenous antibiotics (eg, penicillin, ampicillin) for 4 to 6 weeks, followed by ... In most cases, the bacteria are resistant to penicillin drugs. If an abscess has formed, it may ...

Development of an aptamer-ampicillin conjugate for treating biofilms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lijuan, Cheng; Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha, Hunan, 410208; Xing, Yan

Biofilm formation involves the development of extracellular matrix and initially depends on adherence and tropism by flagellar movement. With the widespread development of antibiotic resistance and tolerance of biofilms, there is a growing need for novel anti-infective strategies. No currently approved medications specifically target biofilms. Aptamers are single-stranded nucleic acid molecules that may bind to their targets with high affinity and affect the target functions. We developed a bifunctional conjugate by linking an aptamer targeting bacterial flagella with ampicillin. We investigated its influence on biofilm prevention and dissolution by ultraviolet–visible spectrophotometry, inverted microscopy, and atomic force microscopy. This conjugate hadmore » distinctive antibacterial activity. Notably, the conjugate was more active than either component, and thus had a synergistic effect against biofilms.« less

[Development and application of reference materials containing mixed degradation products of amoxicillin and ampicillin].

PubMed

Li, Wei; Zhang, Wei-Qing; Li, Xiang; Hu, Chang-Qin

2014-09-01

Reference materials containing mixed degradation products of amoxicillin and ampicillin were developed after optimization of preparation processes. The target impurities were obtained by controlled stress testing, and each major component was identified with HPLC-MS and compared with single traceable reference standard each. The developed reference materials were applied to system suitability test for verifying HPLC system performed in accordance with set forth in China Pharmacopeia and identification of major impurities in samples based on retention and spectra information, which have advantages over the methods put forth in foreign pharmacopoeias. The development and application of the reference materials offer an effective way for rapid identification of impurities in chromatograms, and provide references for analyzing source of impurities and evaluation of drug quality.

21 CFR 520.90f - Ampicillin trihydrate boluses.

Code of Federal Regulations, 2012 CFR

2012-04-01

... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered for... coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp...

21 CFR 520.90f - Ampicillin trihydrate boluses.

Code of Federal Regulations, 2010 CFR

2010-04-01

... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered for... coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp...

21 CFR 520.90f - Ampicillin trihydrate boluses.

Code of Federal Regulations, 2011 CFR

2011-04-01

... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered for... coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp...

21 CFR 522.90c - Ampicillin sodium.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... (including S. equi), Escherichia coli, and Proteus mirabilis, and skin and soft tissue infections (abscesses and wounds) due to Staphylococcus spp., Streptococcus spp., E. coli, and P. mirabilis, when caused by...

21 CFR 522.90c - Ampicillin sodium.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... (including S. equi), Escherichia coli, and Proteus mirabilis, and skin and soft tissue infections (abscesses and wounds) due to Staphylococcus spp., Streptococcus spp., E. coli, and P. mirabilis, when caused by...

Evaluation of the anti-Listeria potentials of some plant-derived triterpenes.

PubMed

Penduka, Dambudzo; Mosa, Rebamang; Simelane, Mthokozisi; Basson, Albert; Okoh, Anthony; Opoku, Andy

2014-07-23

Listeriosis is a fatal disease caused by pathogenic Listeria bacteria and it is most prevalent in immune-compromised individuals. The increase in numbers of immune-compromised individuals against a background of Listeria antibiotic resistance, limits listeriosis treatment options. This therefore calls for research into substitute treatments, of which, medicinal plants derived compounds offer a viable alternative. The broth microdilution assay was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of three plant triterpenes namely 3β-hydroxylanosta-9,24-dien-21-oic acid, methyl-3β-hydroxylanosta-9,24-dien-21-oate and 3β-acetylursolic acid, against Listeria monocytogenes, Listeria ivanovii and Listeria grayi species. The chequerboard method was used to assess the interactions between the triterpenes and conventional antibiotics: ampicillin, neomycin, gentamicin and penicillin G. The lactate dehydrogenase membrane damage method was used to assess the triterpenes' membrane damaging potentials against the Listeria bacteria. The triterpenes' MIC values were found to range from 0.185 to 1.67 mg/ml while, the MBC determination assay results revealed that the test triterpenes were bacteriostatic against the Listeria bacteria. The interactions involving 3β-hydroxylanosta-9,24-dien-21-oic acid were mainly additive with ampicillin and synergistic with neomycin, gentamicin and penicillin G. The interactions involving methyl-3β-hydroxylanosta-9,24-dien-21-oate were mainly antagonistic with ampicillin, indifferent with neomycin, ranging from synergistic to indifference with gentamicin and synergistic with penicillin G. The interactions involving 3β-acetylursolic acid were mainly indifferent with ampicillin, synergistic with neomycin and gentamicin while ranging between synergistic and additive with penicillin G. The low levels of cytosolic lactate dehydrogenase released from the cells treated with 4× MIC concentration of the triterpenes in comparison to that of cells treated with 3% Triton X-100 proved that membrane damage was not the mode of action of the triterpenes. This study therefore shows the potential that these plant triterpenes have in listeriosis chemotherapy especially as shown by the favourable interactions they had with penicillin G, one of the antibiotics of choice in listeriosis treatment.

Population Biology of Intestinal Enterococcus Isolates from Hospitalized and Nonhospitalized Individuals in Different Age Groups

PubMed Central

Tedim, Ana P.; Ruiz-Garbajosa, Patricia; Corander, Jukka; Rodríguez, Concepción M.; Cantón, Rafael; Willems, Rob J.; Baquero, Fernando

2014-01-01

The diversity of enterococcal populations from fecal samples from hospitalized (n = 133) and nonhospitalized individuals (n = 173) of different age groups (group I, ages 0 to 19 years; group II, ages 20 to 59 years; group III, ages ≥60 years) was analyzed. Enterococci were recovered at similar rates from hospitalized and nonhospitalized persons (77.44% to 79.77%) of all age groups (75.0% to 82.61%). Enterococcus faecalis and Enterococcus faecium were predominant, although seven other Enterococcus species were identified. E. faecalis and E. faecium (including ampicillin-resistant E. faecium) colonization rates in nonhospitalized persons were age independent. For inpatients, E. faecalis colonization rates were age independent, but E. faecium colonization rates (particularly the rates of ampicillin-resistant E. faecium colonization) significantly increased with age. The population structure of E. faecium and E. faecalis was determined by superimposing goeBURST and Bayesian analysis of the population structure (BAPS). Most E. faecium sequence types (STs; 150 isolates belonging to 75 STs) were linked to BAPS groups 1 (22.0%), 2 (31.3%), and 3 (36.7%). A positive association between hospital isolates and BAPS subgroups 2.1a and 3.3a (which included major ampicillin-resistant E. faecium human lineages) and between community-based ampicillin-resistant E. faecium isolates and BAPS subgroups 1.2 and 3.3b was found. Most E. faecalis isolates (130 isolates belonging to 58 STs) were grouped into 3 BAPS groups, BAPS groups 1 (36.9%), 2 (40.0%), and 3 (23.1%), with each one comprising widespread lineages. No positive associations with age or hospitalization were established. The diversity and dynamics of enterococcal populations in the fecal microbiota of healthy humans are largely unexplored, with the available knowledge being fragmented and contradictory. The study offers a novel and comprehensive analysis of enterococcal population landscapes and suggests that E. faecium populations from hospitalized patients and from community-based individuals differ, with a predominance of certain clonal lineages, often in association with elderly individuals, occurring in the hospital setting. PMID:25548052

Influence of TEM-1 β-Lactamase on the Pharmacodynamic Activity of Simulated Total versus Free-Drug Serum Concentrations of Cefditoren (400 Milligrams) versus Amoxicillin-Clavulanic Acid (2,000/125 Milligrams) against Haemophilus influenzae Strains Exhibiting an N526K Mutation in the ftsI Gene▿

PubMed Central

Torrico, M.; Aguilar, L.; González, N.; Giménez, M. J.; Echeverría, O.; Cafini, F.; Sevillano, D.; Alou, L.; Coronel, P.; Prieto, J.

2007-01-01

The aim of this study was to explore bactericidal activity of total and free serum simulated concentrations after the oral administration of cefditoren (400 mg, twice daily [bid]) versus the oral administration of amoxicillin-clavulanic acid extended release formulation (2,000/125 mg bid) against Haemophilus influenzae. A computerized pharmacodynamic simulation was performed, and colony counts and β-lactamase activity were determined over 48 h. Three strains were used: ampicillin-susceptible, β-lactamase-negative ampicillin-resistant (BLNAR) (also resistant to amoxicillin-clavulanic acid) and β-lactamase-positive amoxicillin-clavulanic acid-resistant (BLPACR) strains, with cefditoren MICs of ≤0.12 μg/ml and amoxicillin-clavulanic acid MICs of 2, 8, and 8 μg/ml, respectively. Against the ampicillin-susceptible and BLNAR strains, bactericidal activity (≥3 log10 reduction) was obtained from 6 h on with either total and free cefditoren or amoxicillin-clavulanic acid. Against the BLPACR strain, free cefditoren showed bactericidal activity from 8 h on. In amoxicillin-clavulanic acid simulations the increase in colony counts from 4 h on occurred in parallel with the increase in β-lactamase activity for the BLPACR strain. Since both BLNAR and BLPACR strains exhibited the same MIC, this was due to the significantly lower (P ≤ 0.012) amoxicillin concentrations from 4 h on in simulations with β-lactamase positive versus negative strains, thus decreasing the time above MIC (T>MIC). From a pharmacodynamic point of view, the theoretical amoxicillin T>MIC against strains with elevated ampicillin/amoxicillin-clavulanic acid MICs should be considered with caution since the presence of β-lactamase inactivates the antibiotic, thus rendering inaccurate theoretical calculations. The experimental bactericidal activity of cefditoren is maintained over the dosing interval regardless of the presence of a mutation in the ftsI gene or β-lactamase production. PMID:17664320

Novel Therapies for Acinetobacter Osteomyelitis

DTIC Science & Technology

2009-01-01

deployed soldiers. An additional problem is that while there are some effective antibiotics against Acinetobacter (i.e. Colistin and Imipenem ), they are...of Acinetobacter baumannii with confirmed resistance to amikacin, ampicillin, aztraeonam, ceftriaxone, ciprofloxacin, gentamicin, imipenem

Antibiotic Susceptibilities of Genetically Characterized Streptococcus milleri Group Strains

PubMed Central

Tracy, Michael; Wanahita, Anna; Shuhatovich, Yevgeny; Goldsmith, Elizabeth A.; Clarridge, Jill E.; Musher, Daniel M.

2001-01-01

Previous studies of the antibiotic susceptibility of Streptococcus milleri group organisms have distinguished among species by using phenotypic techniques. Using 44 isolates that were speciated by 16S rRNA gene sequencing, we studied the MICs and minimum bactericidal concentrations of penicillin, ampicillin, ceftriaxone, and clindamycin for Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus. None of the organisms was resistant to beta-lactam antibiotics, although a few isolates were intermediately resistant; one strain of S. anginosus was tolerant to ampicillin, and another was tolerant to ceftriaxone. Six isolates were resistant to clindamycin, with representation from each of the three species. Relatively small differences in antibiotic susceptibilities among species of the S. milleri group show that speciation is unlikely to be important in selecting an antibiotic to treat infection caused by one of these isolates. PMID:11302819

Enterococcal Endocarditis: Can We Win the War?

PubMed Central

Munita, Jose M.

2015-01-01

Treatment of enterococcal infections has long been recognized as an important clinical challenge, particularly in the setting of infective endocarditis (IE). Furthermore, the increase prevalence of isolates exhibiting multidrug resistance (MDR) to traditional anti-enterococcal antibiotics such as ampicillin, vancomycin and aminoglycosides (high-level resistance) poses immense therapeutic dilemmas in hospitals around the world. Unlike IE caused by most isolates of Enterococcus faecalis, which still retain susceptibility to ampicillin and vancomycin, the emergence and dissemination of a hospital-associated genetic clade of multidrug resistant Enterococcus faecium, markedly limits the therapeutic options. The best treatment of IE MDR enterococcal endocarditis is unknown and the paucity of antibiotics with bactericidal activity against these organisms is a cause of serious concern. Although it appears that we are winning the war against E. faecalis, the battle rages on against isolates of multidrug-resistant E. faecium. PMID:22661339

LC-MS/MS measurement of ampicillin residue in chicken tissues at 2 days after in-feed administration

PubMed Central

HAMAMOTO, Kouko; MIZUNO, Yasuharu

2017-01-01

We assessed ampicillin (ABPC) concentrations of liver, kidney and skin at a 2-day withdrawal period in ten male and ten female White Leghorn chickens fed the diet containing ABPC (ABPC medicated feed 40 mg/kg body weight/day) for a week. The ABPC residues were measured with liquid chromatography–tandem mass spectrometry and the mean recoveries and quantitation limits ranged from 93.0% to 102.7% and from 0.1 to 1.4 ng/g, respectively. The residual ABPC concentrations were ≤7.82 ng/g for the skin and ≤0.64 ng/g for the kidney, suggesting below the Japanese provisional maximum residue limits. These results revealed that the analytical method is developed for residue ABPC and that the withdrawal period is appropriate. PMID:28190817

Longitudinal surveillance of Haemophilus influenzae isolates from pediatric patients with meningitis throughout Japan, 2000-2011.

PubMed

Ubukata, Kimiko; Chiba, Naoko; Morozumi, Miyuki; Iwata, Satoshi; Sunakawa, Keisuke

2013-02-01

In Japan, β-lactamase-nonproducing, ampicillin-resistant organisms have been evident among Haemophilus influenzae type b (Hib) isolates since 2000, when no appropriate vaccine had been approved. We therefore performed molecular analysis of agents causing H. influenzae meningitis nationwide over the following 10 years. Some 285 institutions have participated in surveillance since 2000. The capsular type and resistance genes of 1,353 isolates and 23 cerebrospinal fluid samples from pediatric patients with meningitis we had received from 2000 to 2011 were analyzed by polymerase chain reaction. Blood and spinal fluid test results obtained when patients were admitted were examined for correlation with outcomes. Hib was found in 98.9 % of isolates. We received more than 100 Hib isolates per year until vaccination began in December 2008, when these isolates decreased, especially since establishment of a special fund to promote vaccination in November 2010. Decreased incidence among infants 7 months to 2 years old has been particularly notable. However, the rate of ampicillin-resistant organisms has increased to more than 60 % of all isolates since 2009. We received 587 replies to a questionnaire concerning outcomes, indicating 2 % mortality and 17.7 % serious morbidity. Age of 6 months or younger and presence of disseminated intravascular coagulation at admission were related to an unfavorable outcome (p < 0.05), but ampicillin resistance was not. Combination therapy with third-generation cephem and carbapenem agents was used initially for 72 % of patients. Routine immunization can prevent Hib meningitis in children.

Antimicrobial-induced endotoxin and cytokine activity in an in vitro model of septicemia in foals.

PubMed

Bentley, Adrienne P; Barton, Michelle H; Lee, Margie D; Norton, Natalie A; Moore, James N

2002-05-01

To determine which antimicrobials that are used to treat neonatal foals with septicemia attributable to Escherichia coli will minimize endotoxin release from bacteria and subsequent activity of inflammatory mediators while maintaining bactericidal efficacy. Blood samples from 10 healthy foals. Escherichia coli isolates A and B were isolated from 2 septicemic foals, and minimal inhibitory concentrations (MIC) were determined for 9 antimicrobials. Five of these antimicrobials were tested in vitro at 2 and 20 times their respective MIC. Whole blood or mononuclear cells grown in tissue-culture media were incubated with 105 colony-forming units of E. coli and each antimicrobial or saline (0.9% NaCl) solution. After 6 hours, number of viable bacteria remaining was determined, and supernatant was tested for endotoxin and tumor necrosis activity. Testing in whole blood was compromised by bactericidal effects of the blood itself. In mononuclear cell suspensions, each antimicrobial significantly reduced the number of viable bacteria to low or undetectable amounts. Antimicrobials did not differ significantly in efficacy of bacterial killing. Amikacin used alone or in combination with ampicillin resulted in significantly less endotoxin activity than did ampicillin, imipenem, or ceftiofur alone. There was a correlation between TNF-alpha and endotoxin activity. Aminoglycosides appear less likely to induce endotoxemia and TNF-alpha synthesis during bactericidal treatment of E. coli septicemia, compared with beta-lactam antimicrobials. Use of ampicillin, imipenem, or ceftiofur in the treatment of septicemic neonatal foals should be accompanied by appropriate treatment for endotoxemia.

Characterization of integron mediated antimicrobial resistance in Salmonella isolated from diseased swine

PubMed Central

White, David G.; Zhao, Shaohua; McDermott, Patrick F.; Ayers, Sherry; Friedman, Sharon; Sherwood, Julie; Breider-Foley, Missy; Nolan, Lisa K.

2003-01-01

Forty-two Salmonella isolates obtained from diseased swine were genetically characterized for the presence of specific antimicrobial resistance mechanisms. Twenty of these isolates were characterized as S. Typhimurium DT104 strains. Pulsed-field gel electrophoresis was used to determine genetic relatedness and revealed 20 distinct genetic patterns among the 42 isolates. However, all DT104 isolates fell within 2 closely related genetic clusters. Other Salmonella isolates were genetically grouped together according to serotype. All DT104 isolates displayed the penta-resistance phenotype to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline. Resistance to sulfamethoxazole, tetracycline, streptomycin, kanamycin, and ampicillin was most common among the non-DT104 Salmonella isolates. All DT104 strains contained 2 chromosomal integrons of 1000 and 1200 base pairs. The DNA sequencing revealed that the 2 integrons contained genes encoding a resistance to streptomycin and ampicillin, respectively. None of the non-DT104 strains showed the same pattern, although several strains possessed integrons of 1000 base pairs or larger. However, the majority of non-DT104 Salmonella strains did not possess any integrons. Two Salmonella isolates displayed tolerance to the organic solvent cyclohexane, indicating the possibility that they are overexpressing chromosomal regulatory genes marA or soxS or the associated multidrug efflux pump, acrAB. This research suggests that integrons contribute to antimicrobial resistance among specific swine Salmonella serotypes; however, they are not as widely disseminated among non-Typhimurium swine Salmonella serotypes as previously thought. PMID:12528827

21 CFR 520.90b - Ampicillin trihydrate tablets.

Code of Federal Regulations, 2012 CFR

2012-04-01

... mirabilis, and Pasteurella spp., urinary tract infections (cystitis) due to Streptococcus spp., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due to... treatment of infections caused by susceptible organisms as follows: Upper respiratory infections...

Drug-sensitivity of El Tor vibrio strains isolated in the Philippines in 1964 and 1965*

PubMed Central

Kuwahara, Shogo; Goto, Sachiko; Kimura, Masatake; Abe, Hisao

1967-01-01

About 1500 strains of El Tor vibrios, isolated in 1964 and 1965 in the Philippines, were examined for their susceptibilities to 17 drugs. All the strains tested were highly sensitive to dihydroxymethyl-furalazine, and most were highly sensitive to tetracycline hydrochloride, chloramphenicol and erythromycin, and moderately sensitive to novobiocin, dihydrostreptomycin sulfate, kanamycin and neomycin. They showed a remarkable fluctuation of sensitivity to ampicillin, cefaloridine, cefalotin and sulfafurazole, and a high resistance to benzylpenicillin sodium, oleandomycin and spiramycin. Experimental confirmation was provided of the fact that El Tor vibrios and non-agglutinable vibrios can be distinguished from classical cholera vibrios by their resistance to polymyxin B and colistin. Highly streptomycin-resistant strains, and to a lesser extent ampicillin- and sulfafurazole-resistant strains, were relatively often isolated from cholera patients who had been treated with antibiotics. One patient yielded a strain resistant to tetracycline, chloramphenicol, streptomycin and sulfafurazole. PMID:4870079

Mass flows and removal of antibiotics in two municipal wastewater treatment plants.

PubMed

Li, Bing; Zhang, Tong

2011-05-01

The mass flows and removal of 20 antibiotics of seven classes in two wastewater treatment plants (WWTPs) of Hong Kong were investigated in different seasons of a whole year, using bihourly 24h flow proportional composite samples. Antibiotics were detected at concentrations of 3.2-1718, 1.3-1176 and 1.1-233ngL(-1) in influents, secondary and disinfection effluents. Total daily discharges of all the detected antibiotics from effluents of Shatin and Stanley WWTPs were 470-710 and 3.0-5.2gd(-1), respectively. Ampicillin, cefalexin, sulfamethoxazole, sulfadiazine, sulfamethazine, chlortetracycline and vancomycin were effectively (52-100%) eliminated by activated sludge process while ampicillin and cefalexin were effectively (91-99%) eliminated by disinfection. Bihourly variation analysis showed that concentrations of the major antibiotics in influents varied more significantly in Stanley WWTP which served small communities. Copyright © 2011 Elsevier Ltd. All rights reserved.

Successful treatment of maternal listeria monocytogenes bacteremia in the first trimester of pregnancy: A case report and literature review.

PubMed

Chan, Lai-Man; Lin, Ho-Hsiung; Hsiao, Sheng-Mou

2018-06-01

To report detailed clinical history and management of maternal listeria infection in the first trimester. A 34-year-old woman at 11 gestational weeks was infected by Listeria monocytogenes with clinical symptoms of acute onset of a fever with subsequent headache and neck stiffness, and was treated with intravenous ampicillin at 2 g every 4 h for 3 weeks. A healthy, unaffected male baby was delivered at term. Histopathologic examination of the placenta did not reveal any chorioamnionitis, granulomas, microabscesses or vasculitis. The neonate developed well without any neurologic compromise at a six-week postnatal follow-up visit. A favorable outcome of maternal listeria infection in the first trimester may be anticipated. Besides, intravenous ampicillin with or without gentamicin should be a reasonable treatment option for maternal listeria infection in the first trimester. Copyright © 2018. Published by Elsevier B.V.

R Factors in Strains of Salmonella typhi and Shigella dysenteriae 1 Isolated During Epidemics in Mexico: Classification by Compatibility

PubMed Central

Datta, Naomi; Olarte, J.

1974-01-01

All 17 Salmonella typhi strains tested from the epidemic in Mexico carried R factors of compatibility group H, conferring resistance to chloramphenicol, streptomycin, tetracycline, and sulfonamides. Some S. typhi strains carried, in addition, non-conjugative, ampicillin resistance plasmids and R factors of the I or A–C complex. All 20 Shigella dysenteriae 1 strains tested of epidemic origin carried O-group R factors. Ampicillin resistance in S. dysenteriae 1 was not proved to be plasmid borne. R factors of group H were not identified in any of the tested Mexican isolates other than S. typhi, but R factors of group O were identified in Escherichia coli, Shigella flexneri, and one strain of S. typhi, as well as in the epidemic S. dysenteriae. An R factor was identified which seemed to have two compatibility specificities, groups Iω and O. PMID:4599123

[Prevalence and antimicrobial behavior of Campylobacter jejuni and Campylobacter coli in children with diarrhea in Loja city, Ecuador].

PubMed

Simaluiza, Rosa; Toledo, Zorayda; Fernández, Heriberto

2018-04-01

Campylobacter is an important agent of diarrhea in humans. In Ecuador, the information on Campylobacter is scarce and there are not antecedents about antimicrobial susceptibility. To describe Campylobacter prevalence in children with diarrhea and their behavior against five antimicrobials in vitro. We studied 253 children with diarrhea aging 7 months to 9 years who consulted for diarrhea in two hospitals in the city of Loja. Fecal samples were cultured and identification by tests by phenotypic tests and multiplex PCR. Susceptibility to 5 antibiotics was determined by the disc-diffusion method. Campylobacter was found in 16 (6.3%) children, being C. jejuni the most frequent one (5.1%), followed by C. coli (1.2%). All strains were susceptible to gentamicin and ampicillin/clavulanic acid, being found low resistance to ampicillin and erythromycin and high resistance to ciprofloxacin.

Synthesis, evaluation and modeling of some triazolothienopyrimidinones as anti-inflammatory and antimicrobial agents.

PubMed

Bekhit, Adnan A; Farghaly, Ahmed M; Shafik, Ragab M; Elsemary, Mona Ma; El-Shoukrofy, Mai S; Bekhit, Alaa El-Din A; Ibrahim, Tamer M

2017-06-01

New triazolotetrahydrobenzothienopyrimidinone derivatives were synthesized. Their structures were confirmed, and their anti-inflammatory, antimicrobial activities and ulcerogenic potentials were evaluated. Compounds 7a, 10a and 11a showed minimal ulcerogenic effect and high selectivity toward human recombinant COX-2 over COX-1 enzyme with IC 50 values of 1.39, 1.22 and 0.56 μM, respectively. Their docking outcome correlated with their biological activity and confirmed the high selectivity binding toward COX-2. Compound 12b displayed antimicrobial activity comparable to that of ampicillin against Escherichia coli while compounds 6 and 11c were similar to ampicillin against Staphylococcus aureus. In addition, compounds 7a, 9a, 10b and 11c showed dual anti-inflammatory/antimicrobial activities. This work represents a promising matrix for developing new potential anti-inflammatory, antimicrobial and dual antimicrobial/anti-inflammatory candidates. [Formula: see text].

[Analysis of antibiotic susceptibility of foodborne Listeria monocytogenes in China].

PubMed

Yang, Yang; Fu, Ping; Guo, Yunchang; Liu, Xiurmei

2008-03-01

To study the antibiotic susceptibility of foodborne Listeria monocytogenes in China. The susceptibilities of 476 strains of foodborne Listeria monocytogenes to antibiotics were determined in Broth Microdilution Susceptibility Testing in Clinical and Laboratory Standards Institute. The antibiotics of gentamicin, ampicillin, penicillin, tetracycline, doxycycline, imipenem, erythromycin, ciprofloxacin, levofloxacin, cephalothin, rifampin, vancomycin, chloramphenicol, Trimethoprim-sulfamethoxazole, ampicillin-sulbactam were used. The rates of antibiotic resistance in 467 is olates were 4.5%. Tetracycline resistance was most prevalent, accouting for 4.07% . The foods that the rates of antibiotic resistance were highest were vegetable (10%). Among 14 provinces, Jilin, Hubei and Hebei were the third top, the rate of which were 19.6% and 9.1% and 8%, respectively. It was suggested that antibiotic resistance exists in foodborne Listeria monocytogenes to a certain extent in China. It should pay more attention to the use of drugs in prevention and clinic treatment to reduce the antibiotic resistant strains.

Effect of penicillin and virginiamycin on drug resistance in lactose-fermenting enteric flora.

PubMed

Gaines, S A; Rollins, L D; Williams, R D; Selwyn, M

1980-03-01

Three groups of beagle dogs were fed either a control diet, a diet containing virginiamycin (55 microgram/g of diet), or a diet containing penicillin (110 microgram/g of diet). The proportions of lactose-fermenting organisms in their feces that were resistant to ampicillin, dihydrostreptomycin, tetracycline, or chloramphenicol were measured by a comparative plate-counting procedure. Both antibiotic-supplemented diets resulted in an increase (P < 0.001) in the occurrence of ampicillin, dihydrostreptomycin, and tetracycline resistances during the time of their administration. The occurrence of these resistances was greater (P < 0.001) in the group receiving penicillin than in the group receiving virginiamycin. In addition to the above resistances, a greater (P < 0.001) occurrence of resistance to a sulfonamide (sulfamethoxypyridazine) due to treatment was found by susceptibility testing of isolates. Representative isolates were able to transfer their resistance to a strain of Escherichia coli K-12.

Removal of veterinary antibiotics from wastewater by electrocoagulation.

PubMed

Baran, Wojciech; Adamek, Ewa; Jajko, Marcin; Sobczak, Andrzej

2018-03-01

The aim of this study was to assess the effectiveness of veterinary antibiotic removal from wastewater using an electrocoagulation method. The removal efficiency of ampicillin, doxycycline, sulfathiazole and tylosin; the antibiotic degradation degree after electrolysis; and the toxicity and qualitative composition of antibiotic solutions after electrocoagulation were determined in the experiments. HPLC-QTOF was used for quantitative and qualitative determination. The eco-toxicity was assessed using the MARA ® assay. After electrocoagulation, the concentration of ampicillin, doxycycline, sulfathiazole and tylosin in wastewater decreased 3.6 ± 3.2%, ∼100%, 3.3 ± 0.4% and 3.1 ± 0.3%, respectively. Doxycycline was the only antibiotic effectively removed from wastewater during electrocoagulation. Simultaneously, part of this antibiotic underwent oxidative degradation. As a result of this process, the eco-toxicity in the reaction environment decreased. Copyright © 2017. Published by Elsevier Ltd.

Etiology of early onset septicemia among neonates at the University College Hospital, Ibadan, Nigeria.

PubMed

Akindolire, Abimbola Ellen; Tongo, Olukemi; Dada-Adegbola, Hannah; Akinyinka, Olusegun

2016-12-30

Neonatal septicemia remains a major cause of newborn deaths in developing countries. Its burden is further compounded by the emergence of multidrug-resistant pathogens, which is related to a lack of antibiotic protocols resulting in unrestricted use of antibiotics. The absence of reliable antibiotic sensitivity testing makes the formulation of antibiotic guidelines and judicious use of antibiotics difficult. This study sought to identify the current bacterial agents associated with early onset septicemia (EOS; age <72 hours) and their antibiotic susceptibility patterns among neonates at the University College Hospital, Ibadan, Nigeria. A total of 202 inborn and outborn neonates with risk factors for or clinical features of septicemia in the first 72 hours of life had samples for blood cultures and antibiotic sensitivity patterns taken prior to treatment. Of the subjects, 95 (47.0%) were inborn and 107 (53.0%) outborn, with a M:F ratio of 1.3:1; 12.5% were culture positive, and the prevalence of EOS was 8.8/1,000 live births. The isolates were Staphylococcus aureus (52%), 30.7% of which were methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae (12%), Enterobacter aerogenes (8%), Enterococcus spp. (8%), Eschericia coli (4%), and other Gram-negatives (12%). All the isolates except Staphylococcus aureus were susceptible to ampicillin, ampicillin/sulbactam, amikacin, gentamicin, and third-generation cephalosporins. All MRSA were sensitive to amikacin, ciprofloxacin, and chloramphenicol, while all methicillin-sensitive Staphylococcus aureus were sensitive to ampicillin/sulbactam. Staphylococcus aureus was the commonest cause of EOS in our setting, with 30.7% of the Staphylococcus aureus isolates being MRSA. Only MRSA demonstrated multidrug resistance.

Empiric Antibiotic Use and Susceptibility in Infants With Bacterial Infections: A Multicenter Retrospective Cohort Study.

PubMed

Feldman, Elana A; McCulloh, Russell J; Myers, Angela L; Aronson, Paul L; Neuman, Mark I; Bradford, Miranda C; Alpern, Elizabeth R; Balamuth, Frances; Blackstone, Mercedes M; Browning, Whitney L; Hayes, Katie; Korman, Rosalynne; Leazer, Rianna C; Nigrovic, Lise E; Marble, Richard; Roben, Emily; Williams, Derek J; Tieder, Joel S

2017-07-20

To assess hospital differences in empirical antibiotic use, bacterial epidemiology, and antimicrobial susceptibility for common antibiotic regimens among young infants with urinary tract infection (UTI), bacteremia, or bacterial meningitis. We reviewed medical records from infants <90 days old presenting to 8 US children's hospitals with UTI, bacteremia, or meningitis. We used the Pediatric Health Information System database to identify cases and empirical antibiotic use and medical record review to determine infection, pathogen, and antimicrobial susceptibility patterns. We compared hospital-level differences in antimicrobial use, pathogen, infection site, and antimicrobial susceptibility. We identified 470 infants with bacterial infections: 362 (77%) with UTI alone and 108 (23%) with meningitis or bacteremia. Infection type did not differ across hospitals ( P = .85). Empirical antibiotic use varied across hospitals ( P < .01), although antimicrobial susceptibility patterns for common empirical regimens were similar. A third-generation cephalosporin would have empirically treated 90% of all ages, 89% in 7- to 28-day-olds, and 91% in 29- to 89-day-olds. The addition of ampicillin would have improved coverage in only 4 cases of bacteremia and meningitis. Ampicillin plus gentamicin would have treated 95%, 89%, and 97% in these age groups, respectively. Empirical antibiotic use differed across regionally diverse US children's hospitals in infants <90 days old with UTI, bacteremia, or meningitis. Antimicrobial susceptibility to common antibiotic regimens was similar across hospitals, and adding ampicillin to a third-generation cephalosporin minimally improves coverage. Our findings support incorporating empirical antibiotic recommendations into national guidelines for infants with suspected bacterial infection. Copyright © 2017 by the American Academy of Pediatrics.

Penicillin-resistant, ampicillin-susceptible Enterococcus faecalis of hospital origin: pbp4 gene polymorphism and genetic diversity.

PubMed

Conceição, Natália; da Silva, Lucas Emanuel Pinheiro; Darini, Ana Lúcia da Costa; Pitondo-Silva, André; de Oliveira, Adriana Gonçalves

2014-12-01

Despite the spread of penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) isolates in diverse countries, the mechanisms leading to this unusual resistance phenotype have not yet been investigated. The aim of this study was to evaluate whether polymorphism in the pbp4 gene is associated with penicillin resistance in PRASEF isolates and to determine their genetic diversity. E. faecalis isolates were recovered from different clinical specimens of hospitalized patients from February 2006 to June 2010. The β-lactam minimal inhibitory concentrations (MICs) were determined by E-test®. The PCR-amplified pbp4 gene was sequenced with an automated sequencer. The genetic diversities of the isolates were established by PFGE (pulsed-field gel electrophoresis) and MLST (multilocus sequencing typing). Seventeen non-producing β-lactamase PRASEF and 10 penicillin-susceptible, ampicillin-susceptible E. faecalis (PSASEF) strains were analyzed. A single-amino-acid substitution (Asp-573→Glu) in the penicillin-binding domain was significantly found in all PRASEF isolates by sequencing of the pbp4 gene but not in the penicillin-susceptible isolates. In contrast to the PSASEF isolates, a majority of the PRASEFs had similar PFGE profiles. Six representative PRASEF isolates were resolved by MLST into ST9 and ST524 and belong to the globally dispersed clonal complex 9 (CC9). In conclusion, it appears quite likely that the amino acid alteration (Asp-573→Glu) found in the PBP4 of the Brazilian PRASEF isolates may account for their reduced susceptibility to penicillin, although other resistance mechanisms remain to be investigated. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of ampicillin, cefazolin and cefoperazone treatments on GLT-1 expressions in the mesocorticolimbic system and ethanol intake in alcohol-preferring rats.

PubMed

Rao, P S S; Goodwani, S; Bell, R L; Wei, Y; Boddu, S H S; Sari, Y

2015-06-04

Chronic ethanol consumption is known to downregulate expression of the major glutamate transporter 1 (GLT-1), which increases extracellular glutamate concentrations in subregions of the mesocorticolimbic reward pathway. While β-lactam antibiotics were initially identified as potent upregulators of GLT-1 expression, only ceftriaxone has been extensively studied in various drug addiction models. Therefore, in this study, adult male alcohol-preferring (P) rats exposed chronically to ethanol were treated with other β-lactam antibiotics, ampicillin, cefazolin or cefoperazone (100mg/kg) once daily for five consecutive days to assess their effects on ethanol consumption. The results demonstrated that each compound significantly reduced ethanol intake compared to the saline-treated control group. Importantly, each compound significantly upregulated both GLT-1 and pAKT expressions in the nucleus accumbens and prefrontal cortex compared to saline-treated control group. In addition, only cefoperazone significantly inhibited hepatic aldehyde dehydrogenase-2 enzyme activity. Moreover, these β-lactams exerted only a transient effect on sucrose drinking, suggesting specificity for chronically inhibiting ethanol reward in adult male P rats. Cerebrospinal fluid concentrations of ampicillin, cefazolin or cefoperazone have been confirmed using high-performance liquid chromatography. These findings demonstrate that multiple β-lactam antibiotics demonstrate efficacy in reducing alcohol consumption and appear to be potential therapeutic compounds for treating alcohol abuse and/or dependence. In addition, these results suggest that pAKT may be an important player in this effect, possibly through increased transcription of GLT-1. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Excipient-mediated alteration in drug bioavailability in the rat depends on the sex of the animal.

PubMed

Mai, Yang; Afonso-Pereira, Francisco; Murdan, Sudaxshina; Basit, Abdul W

2017-09-30

The pharmaceutical excipient, polyethylene glycol 400 (PEG 400), unexpectedly alters the bioavailability of the BCS class III drug ranitidine in a sex-dependent manner. As ranitidine is a substrate for the efflux transporter P-glycoprotein (P-gp), we hypothesized that the sex-related influence could be due to interactions between PEG 400 and P-gp. In this study, we tested this hypothesis by: i) measuring the influence of PEG 400 on the oral bioavailability of another P-gp substrate (ampicillin) and of a non-P-gp substrate (metformin); and ii) measuring the effect of PEG 400 on drug bioavailability in the presence of a P-gp inhibitor (cyclosporine A) in male and female rats. We found that PEG 400 significantly increased (p<0.05) the bioavailability of ampicillin (the P-gp substrate) in male rats, but not in female ones. In contrast, PEG 400 had no influence on the bioavailability of the non-P-gp substrate, metformin in male or female rats. Inhibition of P-gp by oral pre-treatment with cyclosporine A increased the bioavailability of the P-gp substrates (ampicillin and ranitidine) in males and females (p<0.05), and to a greater extent in males, but had no influence on the bioavailability of metformin in either male or female rats. These results prove the hypothesis that the sex-specific effect of PEG 400 on the bioavailability of certain drugs is due to the interaction of PEG 400 with the efflux transporter P-gp. Copyright © 2017 Elsevier B.V. All rights reserved.

[Asymptomatic bacteruiria frequency in pregnant women and uropathogen in vitro antimicrobial sensitivity].

PubMed

Hernández Blas, Fernanda; López Carmona, Juan Manuel; Rodríguez Moctezuma, José Raymundo; Peralta Pedrero, María Luisa; Rodríguez Gutiérrez, Román Salvador; Ortiz Aguirre, Alma Rosa

2007-06-01

To estimate the frequency of asymptomatic bacteriuria in pregnant women attended in Family Medicine Units of the Instituto Mexicano del Seguro Social and to determine the in vitro sensitivity rate of the microorganisms to ampicillin, trimethoprim-sulfamethoxazole, nitrofurantoin and amikacin. We carried out an observational, prospective and transversal study at Family Medicine Units 62 and 64 of the Mexico State Delegation, located in the urban area of Mexico City. Women with lesser than 32 weeks of pregnancy without urinary tract symptoms were included. Urine culture of a midstream urine specimen with > or = 10(5) colony forming units/mL urine of an only germen was used as the gold standard. The in vitro antimicrobial sensitivity was established according to the Bauer Kirby technique. 874 pregnant women were included and 73 had a positive urine culture, with a frequency of 8.4%, IC 95% = 6.6 - 10.2%, of asymptomatic bacteriuria. Escherichia coil was the most frequent isolated agent (77%). In vitro sensitivity to ampicillin of the microorganisms isolated was of 27%, IC 95% = 16 - 38%; to trimethoprim-sulfamethoxazole of 40%, IC95% = 29 - 51%; to amikacin of 68%, IC 95% = 57 - 79%, and to nitrofurantoin of 79%, IC 95% = 70 - 88%. The frequency of asymptomatic bacteriuria in the studied population is similar to the reported by the literature. The in vitro sensitivity rates of E. coil to ampicillin and to trimethoprim-sulfamethoxazole are very low. The best sensitivity corresponded to the nitrofurantoin. The treatment of the asymptomatic bacteriuria must be based on the local patterns of antimicrobial sensitivity and resistance.

Surveillance of antimicrobial susceptibility patterns among Shigella species isolated in China during the 7-year period of 2005-2011.

PubMed

Yang, Haifei; Chen, Guosheng; Zhu, Yulin; Liu, Yanyan; Cheng, Jun; Hu, Lifen; Ye, Ying; Li, Jiabin

2013-03-01

Shigella is a frequent cause of bacterial dysentery in the developing world. Treatment with antibiotics is recommended for shigellosis, but the options are limited due to globally emerging resistance. This study was conducted to determine the frequency and pattern of antimicrobial susceptibility of Shigella in China. We studied the antimicrobial resistance profiles of 308 Shigella spp. strains (260 S. flexneri, 40 S. sonnei, 5 S. boydii, and 3 S. dysenteriae) isolated from fecal samples of patients (age, from 3 months to 92 yr) presenting with diarrhea in different districts of Anhui, China. The antimicrobial resistance of strains was determined by the agar dilution method according to the CSLI guidelines. The most common serogroup in the Shigella isolates was S. flexneri (n=260, 84.4%), followed by S. sonnei (n=40, 13.0%). The highest resistance rate was found for nalidixic acid (96.4%), followed by ampicillin (93.2%), tetracycline (90.9%), and trimethoprim/sulfamethoxazole (80.8%). Among the isolates tested, 280 (91.0%) were multidrug resistant (resistant to ≥2 agents). The most common resistance pattern was the combination of ampicillin, tetracycline, and trimethoprim/sulfamethoxazole (70.8%). Resistance to ampicillin and tetracycline were more common among S. flexneri than among S. sonnei isolates. S. flexneri is predominant in Anhui, China, and its higher antimicrobial resistance rate compared with that of S. sonnei is a cause for concern. Continuous monitoring of resistance patterns is necessary to control the spread of resistance in Shigella. The recommendations for antimicrobial treatment must be updated regularly based on surveillance results.

Analysis of essential gene dynamics under antibiotic stress in Streptococcus sanguinis

PubMed Central

El-Rami, Fadi; Kong, Xiangzhen; Parikh, Hardik; Zhu, Bin; Stone, Victoria; Kitten, Todd; Xu, Ping

2018-01-01

The paradoxical response of Streptococcus sanguinis to drugs prescribed for dental and clinical practices has complicated treatment guidelines and raised the need for further investigation. We conducted a high throughput study on concomitant transcriptome and proteome dynamics in a time course to assess S. sanguinis behaviour under a sub-inhibitory concentration of ampicillin. Temporal changes at the transcriptome and proteome level were monitored to cover essential genes and proteins over a physiological map of intricate pathways. Our findings revealed that translation was the functional category in S. sanguinis that was most enriched in essential proteins. Moreover, essential proteins in this category demonstrated the greatest conservation across 2774 bacterial proteomes, in comparison to other essential functional categories like cell wall biosynthesis and energy production. In comparison to non-essential proteins, essential proteins were less likely to contain ‘degradation-prone’ amino acids at their N-terminal position, suggesting a longer half-life. Despite the ampicillin-induced stress, the transcriptional up-regulation of amino acid-tRNA synthetases and proteomic elevation of amino acid biosynthesis enzymes favoured the enriched components of essential proteins revealing ‘proteomic signatures’ that can be used to bridge the genotype–phenotype gap of S. sanguinis under ampicillin stress. Furthermore, we identified a significant correlation between the levels of mRNA and protein for essential genes and detected essential protein-enriched pathways differentially regulated through a persistent stress response pattern at late time points. We propose that the current findings will help characterize a bacterial model to study the dynamics of essential genes and proteins under clinically relevant stress conditions. PMID:29393020

21 CFR 520.90b - Ampicillin trihydrate tablets.

Code of Federal Regulations, 2011 CFR

2011-04-01

...., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due to Staphylococcus spp., Streptococcus spp., Enterococcus spp., and E. coli. ; infections associated with abscesses..., tonsillitis, and bronchitis due to Streptococcus spp., Staphylococcus spp., Escherichia coli, Proteus...

21 CFR 520.90b - Ampicillin trihydrate tablets.

Code of Federal Regulations, 2010 CFR

2010-04-01

...., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due to Staphylococcus spp., Streptococcus spp., Enterococcus spp., and E. coli. ; infections associated with abscesses..., tonsillitis, and bronchitis due to Streptococcus spp., Staphylococcus spp., Escherichia coli, Proteus...

76 FR 53050 - New Animal Drugs; Ampicillin Trihydrate, Bacitracin Methylene Disalicylate, Flunixin...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-25

... trihydrate. * * * * * (d) * * * (2) * * * (iii) Limitations. Do not treat cattle for more than 7 days. Milk from treated cows must not be used for food during treatment and for 48 hours (4 milkings) after the...

21 CFR 520.90c - Ampicillin trihydrate capsules.

Code of Federal Regulations, 2014 CFR

2014-04-01

... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use in...

21 CFR 520.90c - Ampicillin trihydrate capsules.

Code of Federal Regulations, 2010 CFR

2010-04-01

... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use in...

21 CFR 520.90c - Ampicillin trihydrate capsules.

Code of Federal Regulations, 2012 CFR

2012-04-01

... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use in...

21 CFR 520.90c - Ampicillin trihydrate capsules.

Code of Federal Regulations, 2013 CFR

2013-04-01

... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use in...

21 CFR 520.90c - Ampicillin trihydrate capsules.

Code of Federal Regulations, 2011 CFR

2011-04-01

... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use in...

Capacity of mesoporous bioactive glass nanoparticles to deliver therapeutic molecules

NASA Astrophysics Data System (ADS)

El-Fiqi, Ahmed; Kim, Tae-Hyun; Kim, Meeju; Eltohamy, Mohamed; Won, Jong-Eun; Lee, Eun-Jung; Kim, Hae-Won

2012-11-01

Inorganic bioactive nanomaterials are attractive for hard tissue regeneration, including nanocomponents for bone replacement composites and nanovehicles for delivering therapeutics. Bioactive glass nanoparticles (BGn) have recently gained potential usefulness as bone and tooth regeneratives. Here we demonstrate the capacity of the BGn with mesopores to load and deliver therapeutic molecules (drugs and particularly genes). Spherical BGn with sizes of 80-90 nm were produced to obtain 3-5 nm sized mesopores through a sono-reacted sol-gel process. A simulated body fluid test of the mesoporous BGn confirmed their excellent apatite forming ability and the cellular toxicity study demonstrated their good cell viability up to 100 μg ml-1. Small molecules like chemical drug (Na-ampicillin) and gene (small interfering RNA; siRNA) were introduced as model drugs considering the mesopore size of the nanoparticles. Moreover, amine-functionalization allowed switchable surface charge property of the BGn (from -20-30 mV to +20-30 mV). Loading of ampicillin or siRNA saturated within a few hours (~2 h) and reflected the mesopore structure. While the ampicillin released relatively rapidly (~12 h), the siRNA continued to release up to 3 days with almost zero-order kinetics. The siRNA-nanoparticles were easily taken up by the cells, with a transfection efficiency as high as ~80%. The silencing effect of siRNA delivered from the BGn, as examined by using bcl-2 model gene, showed dramatic down-regulation (~15% of control), suggesting the potential use of BGn as a new class of nanovehicles for genes. This, in conjunction with other attractive properties, including size- and mesopore-related high surface area and pore volume, tunable surface chemistry, apatite-forming ability, good cell viability and the possible ion-related stimulatory effects, will potentiate the usefulness of the BGn in hard tissue regeneration.Inorganic bioactive nanomaterials are attractive for hard tissue regeneration, including nanocomponents for bone replacement composites and nanovehicles for delivering therapeutics. Bioactive glass nanoparticles (BGn) have recently gained potential usefulness as bone and tooth regeneratives. Here we demonstrate the capacity of the BGn with mesopores to load and deliver therapeutic molecules (drugs and particularly genes). Spherical BGn with sizes of 80-90 nm were produced to obtain 3-5 nm sized mesopores through a sono-reacted sol-gel process. A simulated body fluid test of the mesoporous BGn confirmed their excellent apatite forming ability and the cellular toxicity study demonstrated their good cell viability up to 100 μg ml-1. Small molecules like chemical drug (Na-ampicillin) and gene (small interfering RNA; siRNA) were introduced as model drugs considering the mesopore size of the nanoparticles. Moreover, amine-functionalization allowed switchable surface charge property of the BGn (from -20-30 mV to +20-30 mV). Loading of ampicillin or siRNA saturated within a few hours (~2 h) and reflected the mesopore structure. While the ampicillin released relatively rapidly (~12 h), the siRNA continued to release up to 3 days with almost zero-order kinetics. The siRNA-nanoparticles were easily taken up by the cells, with a transfection efficiency as high as ~80%. The silencing effect of siRNA delivered from the BGn, as examined by using bcl-2 model gene, showed dramatic down-regulation (~15% of control), suggesting the potential use of BGn as a new class of nanovehicles for genes. This, in conjunction with other attractive properties, including size- and mesopore-related high surface area and pore volume, tunable surface chemistry, apatite-forming ability, good cell viability and the possible ion-related stimulatory effects, will potentiate the usefulness of the BGn in hard tissue regeneration. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr31775c

21 CFR 520.90d - Ampicillin trihydrate for oral suspension.

Code of Federal Regulations, 2012 CFR

2012-04-01

... infections (tracheobronchitis and tonsillitis) due to Escherichia coli, Pseudomonas spp., Proteus spp., Staphylococcus spp., and Streptococcus spp., urinary tract infections (cystitis) due to E. coli, Staphylococcus... infections (septicemia) associated with abscesses, lacerations, and wounds, due to Staphylococcus spp. and...

21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

Code of Federal Regulations, 2010 CFR

2010-04-01

... tract infections due to E. coli, Pseudomonas spp., Proteus spp., Staphylococcus spp., and Streptococcus spp.; tonsillitis due to E. coli, Pseudomonas spp., Streptococcus spp., and Staphylococcus spp.... Treatment of bacterial enteritis (colibacillosis) caused by E. coli and bacterial pneumonia caused by...

21 CFR 520.90d - Ampicillin trihydrate for oral suspension.

Code of Federal Regulations, 2011 CFR

2011-04-01

...., Staphylococcus spp., and Streptococcus spp., urinary tract infections (cystitis) due to E. coli, Staphylococcus spp., Streptococcus spp., and Proteus spp.; bacterial gastroenteritis due to E. coli; generalized... (bacterial pneumonia) due to Staphylococcus spp., Streptococcus spp., E. coli, and Proteus spp.; urinary...

21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

Code of Federal Regulations, 2011 CFR

2011-04-01

... tract infections due to E. coli, Pseudomonas spp., Proteus spp., Staphylococcus spp., and Streptococcus spp.; tonsillitis due to E. coli, Pseudomonas spp., Streptococcus spp., and Staphylococcus spp.... Treatment of bacterial enteritis (colibacillosis) caused by E. coli and bacterial pneumonia caused by...

21 CFR 520.90d - Ampicillin trihydrate for oral suspension.

Code of Federal Regulations, 2010 CFR

2010-04-01

...., Staphylococcus spp., and Streptococcus spp., urinary tract infections (cystitis) due to E. coli, Staphylococcus spp., Streptococcus spp., and Proteus spp.; bacterial gastroenteritis due to E. coli; generalized... (bacterial pneumonia) due to Staphylococcus spp., Streptococcus spp., E. coli, and Proteus spp.; urinary...

21 CFR 522.90b - Ampicillin trihydrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.90b..., gastrointestinal infections, skin infections, soft tissue infections, and postsurgical infections. (iii...

21 CFR 522.90b - Ampicillin trihydrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.90b..., gastrointestinal infections, skin infections, soft tissue infections, and postsurgical infections. (iii...

Demonstrating Effectiveness of Antibiotics Against Known Bacteria Strains

ERIC Educational Resources Information Center

Keefe, Lois M.

1977-01-01

Procedures are described for showing the effectiveness of antibiotics (penicillin, ampicillin, and tetracycline) against a nonpathogenic bacteria strain (Bacillus cereus). Methods are outlined for preparing nutrient agar, sterilizing tubes, pouring agar plates, preparing antibiotic discs, and transferring antibiotic discs to agar plates. (CS)

Potential drug sequestration during extracorporeal membrane oxygenation: results from an ex vivo experiment.

PubMed

Mehta, Nilesh M; Halwick, David R; Dodson, Brenda L; Thompson, John E; Arnold, John H

2007-06-01

Using an ex vivo simulation model we set out to estimate the amount of drug lost due to sequestration within the extracorporeal circuit over time. Simulated closed-loop extracorporeal membrane oxygenation (ECMO) circuits were prepared using a 1.5-m2 silicone membrane oxygenator. Group A consisted of heparin, dopamine, ampicillin, vancomycin, phenobarbital and fentanyl. Group B consisted of epinephrine, cefazolin, hydrocortisone, fosphenytoin and morphine. Drugs were tested in crystalloid and blood-primed circuits. After administration of a one-time dose of drugs in the priming fluid, baseline drug concentrations were obtained (P0). A simultaneous specimen was stored for stability testing at 24 h (P4). Serial post-membrane drug concentrations were then obtained at 30 min (P1), 3 h (P2) and 24 h (P3) from circuit fluid. One hundred and one samples were analyzed. At the end of 24 h in crystalloid-primed circuits, 71.8% of ampicillin, 96.7% of epinephrine, 17.6% of fosphenytoin, 33.3% of heparin, 17.5% of morphine and 87% of fentanyl was lost. At the end of 24 h in blood-primed extracorporeal circuits, 15.4% of ampicillin, 21% of cefazolin, 71% of voriconazole, 31.4% of fosphenytoin, 53.3% of heparin and 100% of fentanyl was lost. There was a significant decrease in overall drug concentrations from 30 min to 24 h for both crystalloid-primed circuits (p = 0.023) and blood-primed circuits (p = 0.04). Our ex vivo study demonstrates serial losses of several drugs commonly used during ECMO therapy. Therapeutic concentrations of fentanyl, voriconazole, antimicrobials and heparin cannot be guaranteed in patients on ECMO.

Changes in bacterial resistance patterns in children with urinary tract infections on antimicrobial prophylaxis at University Hospital in Split

PubMed Central

Ilić, Tanja; Gračan, Sanda; Arapović, Adela; Čapkun, Vesna; Šubat-Dežulović, Mirna; Saraga, Marijan

2011-01-01

Summary Background We assessed prevalence and resistance of uropathogens on antimicrobial agents (AA) from urine cultures (UC) in children hospitalized with urinary tract infections (UTI) at University Hospital in Split. Material/Methods During the 7-year period, children hospitalized only once with UTI alone were compared to those repeatedly hospitalized, and who received long-term antimicrobial prophylaxis (LTAP), as well as those with associated anomalies of the urinary system (US). Results E. coli was the most frequent isolate (67.7%) with resistance to ampicillin by 69.5%, amoxicillin/clavulonic acid by 3.5%, cephalexin by 6.6%, trimethoprim/sulfamethoxazole (TMP-SMX) by 27.5%, and nitrofurantoin by 0.4%. For other uropathogens, AA resistance rates were the following: 64.3%, 5.8%, 10.5%, 21.3%, and 7.9%. The high or increasing resistance to TMP-SMX is characterized by all uropathogens. Patients with anomalies of US showed a lower prevalence of E. coli and Enterococcus sp., but a higher prevalence of Pseudomonas sp., ESBL-producing E. coli and Klebsiella sp. than those without US anomalies. Repeatedly hospitalized patients showed a lower prevalence of E. coli, but a higher prevalence of Pseudomonas sp. and Klebsiella sp. than patients hospitalized only once. Both groups displayed significantly less resistance of Enterococcus sp. In patients receiving LTAP before hospitalization, E. coli was significantly more resistant to ampicillin, amoxicillin/clavulonic acid and TMP/SMX than in those without LTAP. Conclusions Based on our results, we recommend excluding ampicillin altogether, and reconsideration of further use of TMP-SMX, as well as use of nitrofurantoin, cephalexin and amoxicillin/clavulonic acid for LTAP in our region. PMID:21709628

Antibacterial effects of ellagitannins from Acalypha wilkesiana var. macafeana hort.: surface morphology analysis with environmental scanning electron microscopy and synergy with antibiotics.

PubMed

Din, Wardah Mustafa; Jin, Khoo Teng; Ramli, Ramliza; Khaithir, Tzar Mohd Nizam; Wiart, Christophe

2013-09-01

The present study served to gain further insight into the bactericidal effects of ellagitannins from Acalypha wilkesiana var. macafeana hort. against pathogenic bacteria. Ellagitannins from the aerial parts of A. wilkesiana var. macafeana hort. (EAW) inhibited the growth of Bacillus cereus (ATCC 11778), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 11632) and Methicillin-resistant Staphylococcus aureus (MRSA) clinical strain with inhibition zones equal to 11.01 ± 1.53 mm, 16.63 ± 0.11 mm, 11.40 ± 1.10 mm and 8.22 ± 0.19 mm, respectively. The minimal inhibition concentration and the minimal bactericidal concentration of ellagitannins from A. wilkesiana var. macafeana hort. (EAW) against MRSA were 750 µg/mL and 3000 µg/mL, respectively. We then examined the synergistic effect of EAW with three antibiotics, i.e. ampicillin, streptomycin and tetracycline, via the checkerboard assay and time-kill assay and observed that EAW is synergistic with ampicillin against S. aureus (ATCC 11632). Environmental electron scanning microscopy analysis showed cell lysis against S. aureus (ATCC 11632) upon treatment with the ellagitannin fraction. The ellagitannin fraction from A. wilkesiana var. macafeana hort. is bactericidal against gram-positive bacteria tested and works synergistically with ampicillin against S. aureus. Morphology analysis of the cell suggests that the bactericidal property of the ellagitannin fraction mechanism involves lysis of the cell wall. In summary, our studies demonstrate that A. wilkesiana var. macafeana hort. produces bactericidal ellagitannins of clinical and/or cosmetological value. Copyright © 2012 John Wiley & Sons, Ltd.

MASTER: a model to improve and standardize clinical breakpoints for antimicrobial susceptibility testing using forecast probabilities.

PubMed

Blöchliger, Nicolas; Keller, Peter M; Böttger, Erik C; Hombach, Michael

2017-09-01

The procedure for setting clinical breakpoints (CBPs) for antimicrobial susceptibility has been poorly standardized with respect to population data, pharmacokinetic parameters and clinical outcome. Tools to standardize CBP setting could result in improved antibiogram forecast probabilities. We propose a model to estimate probabilities for methodological categorization errors and defined zones of methodological uncertainty (ZMUs), i.e. ranges of zone diameters that cannot reliably be classified. The impact of ZMUs on methodological error rates was used for CBP optimization. The model distinguishes theoretical true inhibition zone diameters from observed diameters, which suffer from methodological variation. True diameter distributions are described with a normal mixture model. The model was fitted to observed inhibition zone diameters of clinical Escherichia coli strains. Repeated measurements for a quality control strain were used to quantify methodological variation. For 9 of 13 antibiotics analysed, our model predicted error rates of < 0.1% applying current EUCAST CBPs. Error rates were > 0.1% for ampicillin, cefoxitin, cefuroxime and amoxicillin/clavulanic acid. Increasing the susceptible CBP (cefoxitin) and introducing ZMUs (ampicillin, cefuroxime, amoxicillin/clavulanic acid) decreased error rates to < 0.1%. ZMUs contained low numbers of isolates for ampicillin and cefuroxime (3% and 6%), whereas the ZMU for amoxicillin/clavulanic acid contained 41% of all isolates and was considered not practical. We demonstrate that CBPs can be improved and standardized by minimizing methodological categorization error rates. ZMUs may be introduced if an intermediate zone is not appropriate for pharmacokinetic/pharmacodynamic or drug dosing reasons. Optimized CBPs will provide a standardized antibiotic susceptibility testing interpretation at a defined level of probability. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Diagnostic Accuracy Assessment of Sensititre and Agar Disk Diffusion for Determining Antimicrobial Resistance Profiles of Bovine Clinical Mastitis Pathogens▿

PubMed Central

Saini, V.; Riekerink, R. G. M. Olde; McClure, J. T.; Barkema, H. W.

2011-01-01

Determining the accuracy and precision of a measuring instrument is pertinent in antimicrobial susceptibility testing. This study was conducted to predict the diagnostic accuracy of the Sensititre MIC mastitis panel (Sensititre) and agar disk diffusion (ADD) method with reference to the manual broth microdilution test method for antimicrobial resistance profiling of Escherichia coli (n = 156), Staphylococcus aureus (n = 154), streptococcal (n = 116), and enterococcal (n = 31) bovine clinical mastitis isolates. The activities of ampicillin, ceftiofur, cephalothin, erythromycin, oxacillin, penicillin, the penicillin-novobiocin combination, pirlimycin, and tetracycline were tested against the isolates. Diagnostic accuracy was determined by estimating the area under the receiver operating characteristic curve; intertest essential and categorical agreements were determined as well. Sensititre and the ADD method demonstrated moderate to highly accurate (71 to 99%) and moderate to perfect (71 to 100%) predictive accuracies for 74 and 76% of the isolate-antimicrobial MIC combinations, respectively. However, the diagnostic accuracy was low for S. aureus-ceftiofur/oxacillin combinations and other streptococcus-ampicillin combinations by either testing method. Essential agreement between Sensititre automatic MIC readings and MIC readings obtained by the broth microdilution test method was 87%. Essential agreement between Sensititre automatic and manual MIC reading methods was 97%. Furthermore, the ADD test method and Sensititre MIC method exhibited 92 and 91% categorical agreement (sensitive, intermediate, resistant) of results, respectively, compared with the reference method. However, both methods demonstrated lower agreement for E. coli-ampicillin/cephalothin combinations than for Gram-positive isolates. In conclusion, the Sensititre and ADD methods had moderate to high diagnostic accuracy and very good essential and categorical agreement for most udder pathogen-antimicrobial combinations and can be readily employed in veterinary diagnostic laboratories. PMID:21270215

Molecular Epidemiology of Enterococcal Bacteremia in Australia

PubMed Central

Pearson, Julie C.; Daley, Denise A.; Le, Tam; Robinson, Owen J.; Gottlieb, Thomas; Howden, Benjamin P.; Johnson, Paul D. R.; Bennett, Catherine M.; Stinear, Timothy P.; Turnidge, John D.

2014-01-01

Enterococci are a major cause of health care-associated infections and account for approximately 10% of all bacteremias globally. The aim of this study was to determine the proportion of enterococcal bacteremia isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to ampicillin and the glycopeptides, and to characterize the molecular epidemiology of the Enterococcus faecalis and Enterococcus faecium isolates. From 1 January to 31 December 2011, 1,079 unique episodes of bacteremia were investigated, of which 95.8% were caused by either E. faecalis (61.0%) or E. faecium (34.8%). The majority of bacteremias were health care associated, and approximately one-third were polymicrobial. Ampicillin resistance was detected in 90.4% of E. faecium isolates but was not detected in E. faecalis isolates. Vancomycin nonsusceptibility was reported in 0.6% and 36.5% of E. faecalis and E. faecium isolates, respectively. Unlike Europe and the United States, where vancomycin resistance in E. faecium is predominately due to the acquisition of the vanA operon, 98.4% of E. faecium isolates harboring van genes carried the vanB operon, and 16.1% of the vanB E. faecium isolates had vancomycin MICs at or below the susceptible breakpoint of the CLSI. Although molecular typing identified 126 E. faecalis pulsed-field gel electrophoresis pulsotypes, >50% belonged to two pulsotypes that were isolated across Australia. E. faecium consisted of 73 pulsotypes from which 43 multilocus sequence types were identified. Almost 90% of the E. faecium isolates were identified as CC17 clones, of which approximately half were characterized as ST203, which was isolated Australia-wide. In conclusion, the Australian Enterococcal Sepsis Outcome Programme (AESOP) study has shown that although they are polyclonal, enterococcal bacteremias in Australia are frequently caused by ampicillin-resistant vanB E. faecium. PMID:24391201

Fluorescent aptasensor for antibiotic detection using magnetic bead composites coated with gold nanoparticles and a nicking enzyme.

PubMed

Luo, Zewei; Wang, Yimin; Lu, Xiaoyong; Chen, Junman; Wei, Fujing; Huang, Zhijun; Zhou, Chen; Duan, Yixiang

2017-09-01

Antibiotic abuse has been bringing serious pollution in water, which is closely related to human health. It is desirable to develop a new strategy for antibiotic detection. To address this problem, a sensitive fluorescent aptasensor for antibiotic detection was developed by utilizing gold nanoparticles modified magnetic bead composites (AuNPs/MBs) and nicking enzyme. AuNPs/MBs were synthesized with the help of polyethylenimine (PEI). The prepared AuNPs/MBs acted as dual-functional scaffolds that owned excellent magnetic separation capacity and strong covalent bio-conjugation. The non-specifically absorbed aptamers in AuNPs/MBs were less than that in MBs. Hence, the fluorescent aptasensor based on AuNPs/MBs show a better signal to background ratio than that based on carboxyl modified magnetic beads (MBs). In this work, ampicillin was employed as a model analyte. In the presence of ampicillin, the specific binding between ampicillin and aptamer induced structure-switching that led to the release of partial complementary DNA (cDNA) of aptamer. Then, the released cDNA initiated the cycle of nicking enzyme assisted signal amplification (NEASA). Therefore, a large amount of taqman probes were cleaved and fluorescence signal was amplified. The prepared fluorescent aptasensor bring sensitive detection in range of 0.1-100 ng mL -1 with the limit of detection of 0.07 ng mL -1 . Furthermore, this aptasensor was also successfully applied in real sample detection with acceptable accuracy. The fluorescent aptasensor provides a promising method for efficient, rapid and sensitive antibiotic detection. Copyright © 2017 Elsevier B.V. All rights reserved.

Using the lentiviral vector system to stably express chicken P-gp and BCRP in MDCK cells for screening the substrates and studying the interplay of both transporters.

PubMed

Zhang, Yujuan; Huang, Jinhu; Liu, Yang; Guo, Tingting; Wang, Liping

2018-06-01

Transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) are known to influence the pharmacokinetics and toxicity of substrate drugs. However, no detailed information is as yet available about functional activity and substrate spectra of chicken P-gp and BCRP. In this study, BCRP single and BCRP/P-gp double-transfected MDCK cell lines (named MDCK-chAbcg2 and MDCK-chAbcg2/Abcb1, respectively) were generated using lentiviral vector system to develop reliable systems for screening the substrates for these two transporters and study the interplay between them. The constructed cell lines significantly expressed functional exogenous proteins and expression persisted for at least 50 generations with no decrease. Enrofloxacin, ciprofloxacin, tilmicosin, sulfadiazine, ampicillin and clindamycin were classified as the substrates of chicken P-gp according to the rules suggested by FDA, as their net efflux ratios were greater than two. Similarly, enrofloxacin, ciprofloxacin, tilmicosin, florfenicol, ampicillin and clindamycin were classified as the substrates of BCRP. Among these drugs, enrofloxacin, ciprofloxacin, tilmicosin, ampicillin, and clindamycin were the cosubstrates of P-gp and BCRP, however, chicken BCRP and P-gp exhibit different affinities to the shared substrates at different concentrations by blocking either one or both transport with specific inhibitors in the coexpression system. It was also found that ceftiofur, amoxicillin and doxycycline were not substrates of either chicken BCRP or the substrates of chicken P-gp. These constructed cell models provide useful systems for high-throughput screening of the potential substrates of chicken BCRP and P-gp as well as the drug-drug interaction mediated via chicken BCRP and P-gp.

Streptococcus agalactiae: prevalence of antimicrobial resistance in vaginal and rectal swabs in Italian pregnant women.

PubMed

Matani, Chiara; Trezzi, Michele; Matteini, Alice; Catalani, Carlotta; Messeri, Daniela; Catalani, Corrado

2016-09-01

Intrapartum antibiotic prophylaxis (IAP) reduces both the vertical transmission of Streptococcus agalactiae or Group B Streptococcus (GBS) and the early onset of neonatal sepsis. However, existing guidelines do not recommend that antimicrobial susceptibility testing (AST) be routinely performed. Penicillin or ampicillin are indicated as first-choice antibiotics, cefazolin being an alternative in the case of history of mild allergic reactions, and vancomycin or clindamycin an alternative in the event of severe reactions. We performed a cross-sectional analysis to identify the presence of any bacterial resistance towards the antibiotics most frequently used for IAP in pregnant women with GBS positive vaginal-rectal swabs, in the Pistoia area of central Italy. Of the 255 tested samples, 65 (25.5%) were positive for GBS. Sensitivity to glycopeptides was over 90%, but lower to ampicillin and penicillin (87.10% and 87.93% respectively). Resistance towards clindamycin and erythromycin was as high as 43.75% and 32.20%. All tested GBS proved susceptible to moxifloxacin, linezolid and tigecycline. Our observed prevalence is aligned or slightly higher than data reported in other series. The less than full effectiveness and low percentages of ampicillin and penicillin sensitivity observed give cause for concern. We confirmed the increase in clindamycin and erythromycin resistance. Glycopeptides can be used as second-line antibiotics, but the complete AST of GBS should always be performed before IAP. Given that gentamicin is used synergically with penicillin when treating chorioamnionitis, it needs to be always included in the AST. This is the first study on the GBS sensitivity profile in Tuscany. Further investigation on a larger scale is required prior to implementing any changes in the current guidelines.

Antimicrobial resistance genes in Actinobacillus pleuropneumoniae, Haemophilus parasuis and Pasteurella multocida isolated from Australian pigs.

PubMed

Dayao, Dae; Gibson, J S; Blackall, P J; Turni, C

2016-07-01

To identify genes associated with the observed antimicrobial resistance in Actinobacillus pleuropneumoniae, Haemophilus parasuis and Pasteurella multocida isolated from Australian pigs. Isolates with known phenotypic resistance to β-lactams, macrolides and tetracycline were screened for the presence of antimicrobial resistance genes. A total of 68 A. pleuropneumoniae, 62 H. parasuis and 20 P. multocida isolates exhibiting phenotypic antimicrobial resistance (A. pleuropneumoniae and P. multocida) or elevated minimal inhibitory concentrations (MICs) (H. parasuis) to any of the following antimicrobial agents - ampicillin, erythromycin, penicillin, tetracycline, tilmicosin and tulathromycin - were screened for a total of 19 associated antimicrobial resistance genes (ARGs) by PCR. The gene bla ROB-1 was found in all ampicillin- and penicillin-resistant isolates, but none harboured the bla TEM-1 gene. The tetB gene was found in 76% (74/97) of tetracycline-resistant isolates, 49/53 A. pleuropneumoniae, 17/30 H. parasuis and 8/14 P. multocida. One A. pleuropneumoniae isolate harboured the tetH gene, but none of the 97 isolates had tetA, tetC, tetD, tetE, tetL, tetM or tetO. A total of 92 isolates were screened for the presence of macrolide resistance genes. None was found to have ermA, ermB, ermC, erm42, mphE, mefA, msrA or msrE. The current study has provided a genetic explanation for the resistance or elevated MIC of the majority of isolates of Australian porcine respiratory pathogens to ampicillin, penicillin and tetracycline. However, the macrolide resistance observed by phenotypic testing remains genetically unexplained and further studies are required. © 2016 Australian Veterinary Association.

High-throughput sequencing reveals the incomplete, short-term recovery of infant gut microbiota following parenteral antibiotic treatment with ampicillin and gentamicin.

PubMed

Fouhy, Fiona; Guinane, Caitriona M; Hussey, Seamus; Wall, Rebecca; Ryan, C Anthony; Dempsey, Eugene M; Murphy, Brendan; Ross, R Paul; Fitzgerald, Gerald F; Stanton, Catherine; Cotter, Paul D

2012-11-01

The infant gut microbiota undergoes dramatic changes during the first 2 years of life. The acquisition and development of this population can be influenced by numerous factors, and antibiotic treatment has been suggested as one of the most significant. Despite this, however, there have been relatively few studies which have investigated the short-term recovery of the infant gut microbiota following antibiotic treatment. The aim of this study was to use high-throughput sequencing (employing both 16S rRNA and rpoB-specific primers) and quantitative PCR to compare the gut microbiota of nine infants who underwent parenteral antibiotic treatment with ampicillin and gentamicin (within 48 h of birth), 4 and 8 weeks after the conclusion of treatment, relative to that of nine matched healthy controls. The investigation revealed that the gut microbiota of the antibiotic-treated infants had significantly higher proportions of Proteobacteria (P = 0.0049) and significantly lower proportions of Actinobacteria (P = 0.00001) (and the associated genus Bifidobacterium [P = 0.0132]) as well as the genus Lactobacillus (P = 0.0182) than the untreated controls 4 weeks after the cessation of treatment. By week 8, the Proteobacteria levels remained significantly higher in the treated infants (P = 0.0049), but the Actinobacteria, Bifidobacterium, and Lactobacillus levels had recovered and were similar to those in the control samples. Despite this recovery of total Bifidobacterium numbers, rpoB-targeted pyrosequencing revealed that the number of different Bifidobacterium species present in the antibiotic-treated infants was reduced. It is thus apparent that the combined use of ampicillin and gentamicin in early life can have significant effects on the evolution of the infant gut microbiota, the long-term health implications of which remain unknown.

High prevalence and antimicrobial resistance of urinary tract infection isolates in febrile young children without localizing signs in Taiwan.

PubMed

Wu, Chang-Teng; Lee, Hao-Yuan; Chen, Chyi-Liang; Tuan, Pao-Lan; Chiu, Cheng-Hsun

2016-04-01

Antimicrobial susceptibility and prevalence of pediatric urinary tract infection (UTI) is very useful for pediatricians in selecting effective antibiotics in time to improve outcomes in patients. This study aimed to determine the prevalence rate, bacterial distribution, and antimicrobial susceptibility of UTI in febrile young children at a teaching hospital in northern Taiwan. From January 2011 to December 2011, all urinary isolates from suspected cases of UTI in febrile young children aged from 1 day to 36 months visiting the Pediatric Emergency Room of Chang Gung Children's Hospital, Taoyuan, Taiwan were identified by conventional methods. Antibiotic susceptibility was determined according to the Clinical and Laboratory Standards Institute. A total of 5470 (78%) from 7009 eligible children were enrolled in the study, and 619 (11.3%) had a diagnosis of UTI. The most prevalent bacterium was Escherichia coli (68%) followed by Klebsiella pneumoniae (8.1%) and Proteus mirabilis (6.8%). Ampicillin, piperacillin, and trimethoprim-sulfamethoxazole (TMP-SMX) showed a higher resistance rate in the three predominant bacteria. All tested bacteria showed higher resistance to ampicillin (79.3%) and TMP-SMX (44.1%), and lower resistance to cefazolin (17.7%) and gentamicin (13.0%). Fourteen percent of the isolates produced extended spectrum β-lactamase (ESBL), among which 93.33% were E. coli isolates. The overall prevalence of UTI in this study was higher than previously reported in febrile children. Higher antimicrobial resistance was found in ampicillin and TMP-SMX. Among commonly used antibiotics, cefazolin and gentamicin are recommended to treat UTI in febrile children aged < 3 years without localizing signs. Copyright © 2015. Published by Elsevier B.V.

T.E.A. Study: three-day ertapenem versus three-day Ampicillin-Sulbactam.

PubMed

Catena, Fausto; Vallicelli, Carlo; Ansaloni, Luca; Sartelli, Massimo; Di Saverio, Salomone; Schiavina, Riccardo; Pasqualini, Eddi; Amaduzzi, Annalisa; Coccolini, Federico; Cucchi, Michele; Lazzareschi, Daniel; Baiocchi, Gian Luca; Pinna, Antonio D

2013-04-30

Intra-abdominal infections are one of the most common infections encountered by a general surgeon. However, despite this prevalence, standardized guidelines outlining the proper use of antibiotic therapy are poorly defined due to a lack of clinical trials investigating the ideal duration of antibiotic treatment. The aim of this study is to compare the efficacy and safety of a three-day treatment regimen of Ampicillin-Sulbactam to that of a three-day regimen of Ertapenem in patients with localized peritonitis ranging from mild to moderate severity. This study is a prospective, multi-center, randomized investigation performed in the Department of General, Emergency, and Transplant Surgery of St. Orsola-Malpighi University Hospital in Bologna, Italy. Discrete data were analyzed using the Chi-squared and Fisher exact tests. Differences between the two study groups were considered statistically significant for p-values less than 0.05. 71 patients were treated with Ertapenem and 71 patients were treated with Ampicillin-Sulbactam. The two groups were comparable in terms of age and gender as well as the site of abdominal infection. Post-operative infection was identified in 12 patients: 10 with wound infections and 2 with intra-abdominal infections. In the Ertapenem group, 69 of the 71 patients (97%) were treated successfully, while the therapy failed in 2 cases (3%). Therapy failures were more frequent in the Unasyn group, amounting to 10 of 71 cases (p = 0.03). According to these preliminary findings, the authors conclude that a three-day Ertapenem treatment regimen is the most effective antibiotic therapy for patients with localized intra-abdominal infections ranging from mild to moderate severity. Trial registration: ClinicalTrials.gov: NCT00630513.

Resistance to antimicrobial agents among Salmonella isolates recovered from layer farms and eggs in the Caribbean region.

PubMed

Adesiyun, Abiodun; Webb, Lloyd; Musai, Lisa; Louison, Bowen; Joseph, George; Stewart-Johnson, Alva; Samlal, Sannandan; Rodrigo, Shelly

2014-12-01

This investigation determined the frequency of resistance of 84 isolates of Salmonella comprising 14 serotypes recovered from layer farms in three Caribbean countries (Trinidad and Tobago, Grenada, and St. Lucia) to eight antimicrobial agents, using the disc diffusion method. Resistance among isolates of Salmonella was related to the country of recovery, type of sample, size of layer farms, and isolate serotype. Overall, all (100.0%) of the isolates exhibited resistance to one or more of seven antimicrobial agents tested, and all were susceptible to chloramphenicol. The resistance detected ranged from 11.9% to sulphamethoxazole-trimethoprim (SXT) to 100.0% to erythromycin. The difference was, however, not statistically significant (P = 0.23). Across countries, for types of samples that yielded Salmonella, significant differences in frequency of resistance were detected only to SXT (P = 0.002) in Trinidad and Tobago and to gentamycin (P = 0.027) in St. Lucia. For the three countries, the frequency of resistance to antimicrobial agents was significantly different for ampicillin (P = 0.001) and SXT (P = 0.032). A total of 83 (98.8%) of the 84 isolates exhibited 39 multidrug resistance patterns. Farm size significantly (P = 0.032) affected the frequency of resistance to kanamycin across the countries. Overall, among the 14 serotypes of Salmonella tested, significant (P < 0.05) differences in frequency of resistance were detected to kanamycin, ampicillin, and SXT. Results suggest that the relatively high frequency of resistance to six of the antimicrobial agents (erythromycin, streptomycin, gentamycin, kanamycin, ampicillin, and tetracycline) tested and the multidrug resistance detected may pose prophylactic and therapeutic concerns for chicken layer farms in the three countries studied.

[Results of two treatment regimens for pyelonephritis during pregnancy and correlation with pregnancy outcome].

PubMed

Calegari, Saron Souza; Konopka, Cristine Kolling; Balestrin, Bruna; Hoffmann, Maurício Scopel; de Souza, Floriano Soeiro; Resener, Elaine Verena

2012-08-01

To determine the epidemiological profile of women admitted for urinary tract infection as well as to verify the most prevalent agents and response to antibiotic therapy. A retrospective study of 106 pregnant women admitted to a university hospital for urinary tract infection treatment during the period between January 2007 to December 2010. The evaluation was based on analysis of the medical records of these pregnant women, with the observation of hospitalization and pregnancy data, as well as its outcome. Statistical analysis was performed using Statistical Package for the Social Science, version 15.0. The bilateral Fisher exact test and Student's t test were used for data analysis, as well as descriptive statistical methods. Positive urine cultures were observed in 60.5% of pregnant women admitted due to urinary tract infection. The most frequent infectious agent was Escherichia coli and no difference in resistance, recurrence or complications was observed between the most frequent etiologic agents. Pregnant women with previous UTI had a higher recurrence risk (OR=10.8; p<0.05). The antibiotics most commonly used during hospitalization were ampicillin and cefazolin. Change of therapeutic agent due to bacterial resistance occurred in 11.9% of patients who took cefazolin and in 20% of patients who took ampicillin (OR=5.5; p<0.05). The rate of gestational complications was the same for both treatments. There was no difference in mean number of days of hospitalization between the treatments. In the studied population ampicillin showed a higher rate of bacterial resistance than cefazolin, requiring a larger number of treatment regimen exchanges, without resulting in differences in clinical outcome or time of hospitalization.

β-Lactam resistance among Haemophilus influenzae isolates in Poland.

PubMed

Kiedrowska, Marlena; Kuch, Alicja; Żabicka, Dorota; Waśko, Izabela; Ronkiewicz, Patrycja; Wasiak, Katarzyna; Bojarska, Katarzyna; Hryniewicz, Waleria; Skoczyńska, Anna

2017-12-01

Haemophilus influenzae is a human-specific Gram-negative coccobacillus responsible for a significant number of respiratory tract infections and severe invasive infections such as meningitis and sepsis. The purpose of this study was to characterise the mechanisms of β-lactam resistance among Polish H. influenzae isolates and to evaluate the resistance detection methods applied. This study was conducted on 117 Polish H. influenzae isolates collected in 2012. Minimum inhibitory concentrations were assessed by broth microdilution. All strains were evaluated using the disk diffusion method and the algorithm proposed by the Nordic Committee on Antimicrobial Susceptibility Testing (NordicAST). To detect changes in penicillin-binding protein 3 (PBP3), PCR screening was performed, followed by ftsI gene sequencing. Neither β-lactamase production nor PBP3 alterations were demonstrated in 76 isolates (65.0%). Susceptibility to ampicillin, amoxicillin, amoxicillin/clavulanic acid, cefuroxime (intravenous) and ceftriaxone was observed in 70.9%, 78.6%, 98.3%, 82.9% and 100% of the isolates, respectively. β-Lactamase production characterised 21 isolates (17.9%). Screening PCR identified 20 isolates (17.1%) with PBP3 alterations, and according to subsequent ftsI sequencing all these strains were finally recognised as gBLNAR (genetically β-lactamase-negative, ampicillin-resistant), among which 65.0% were ampicillin-resistant. According to molecular classification of PBP3 alterations, 95.0% of gBLNAR belonged to group II, representing four subgroups IIa-IId. Haemophilus influenzae resistance to antibiotics requires continuous attention, effective detection methods and a rational policy of antibiotic usage. The algorithm proposed by NordicAST can be applied in routine laboratory work, whereas sequencing of the ftsI gene may be useful in molecular epidemiology studies. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Gentamicin induces efaA expression and biofilm formation in Enterococcus faecalis.

PubMed

Kafil, Hossein Samadi; Mobarez, Ashraf Mohabati; Moghadam, Mehdi Forouzandeh; Hashemi, Zahra Sadat; Yousefi, Mehdi

2016-03-01

Enterococci have been ranked among the leading causes of nosocomial bacteremia and urinary tract infection. This study aimed to investigate the effect of ampicillin, vancomycin, gentamicin and ceftizoxime on biofilm formation and gene expression of colonization factors on Enterococcus faecalis. Twelve clinical isolates of E. faecalis were used to investigate the effect of antibiotics on biofilm formation and gene expression of efaA, asa1, ebpA, esp and ace. Flow system assay and Microtiter plates were used for biofilm assay. Two hundred clinical isolates were used for confirming the effect of antibiotics on biofilm formation. Ampicillin, vancomycin and ceftizoxime did not have any significant effect on biofilm formation, but gentamicin induced biofilm formation in 89% of isolates. In twelve selected isolate gentamicin increased expression of esp (+50.9%) and efaA (+33.9%) genes and reduced or maintained expression of others (asa1:-47.4%, ebpA: 0, ace:-19.2%). Vancomycin increased expression of esp (+89.1%) but reduced the others (asa1: -34.9%, ebpA:-11%, ace:-30%, efaA:-60%). Ceftizoxime increased slightly ebpA (+19.7%) and reduced others (asa1:-66.2%, esp:-35%, ace:-28.1%, efaA:-38.4%). and ampicillin strongly increased expression of ace (+231%), esp (+131%) and ebpA (+83%) but reduced others (asa1:-85.5%, efaA:-47.4%). The findings of the present study showed that antibiotics may have a role in biofilm formation and sustainability of enterococci, especially in case of gentamicin. efaA gene may have an important role, especially in antibiotic induced biofilm formation by gentamicin. Experiments with efaA mutants are needed to investigate the exact effect of efaA on biofilm formation with antibiotic induced cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antibiotic Treatment Attenuates Behavioral and Neurochemical Changes Induced by Exposure of Rats to Group A Streptococcal Antigen

PubMed Central

Lotan, Dafna; Cunningham, Madeleine; Joel, Daphna

2014-01-01

Post-streptococcal A (GAS) sequelae including movement and neuropsychiatric disorders have been associated with improvement in response to antibiotic therapy. Besides eradication of infection, the underlying basis of attenuation of neuropsychiatric symptoms following antibiotic treatment is not known. The aim of the present study was to test the efficacy of antibiotic treatment in a rat model of GAS-related neuropsychiatric disorders. In the model, rats were not infected but were exposed to GAS-antigen or to adjuvants only (Control rats) and treated continuously with the antibiotic ampicillin in their drinking water from the first day of GAS-antigen exposure. Two additional groups of rats (GAS and Control) did not receive ampicillin in their drinking water. Behavior of the four groups was assessed in the forced swim, marble burying and food manipulation assays. We assessed levels of D1 and D2 dopamine receptors and tyrosine hydroxylase in the prefrontal cortex and striatum, and IgG deposition in the prefrontal cortex, striatum and thalamus. Ampicillin treatment prevented emergence of the motor and some of the behavioral alterations induced by GAS-antigen exposure, reduced IgG deposition in the thalamus of GAS-exposed rats, and tended to attenuate the increase in the level of TH and D1 and D2 receptors in their striatum, without concomitantly reducing the level of sera anti-GAS antibodies. Our results reinforce the link between exposure to GAS antigen, dysfunction of central dopaminergic pathways and motor and behavioral alterations. Our data further show that some of these deleterious effects can be attenuated by antibiotic treatment, and supports the latter’s possible efficacy as a prophylactic treatment in GAS-related neuropsychiatric disorders. PMID:24979049

Association between antimicrobial resistance in Escherichia coli isolates from food animals and blood stream isolates from humans in Europe: an ecological study.

PubMed

Vieira, Antonio R; Collignon, Peter; Aarestrup, Frank M; McEwen, Scott A; Hendriksen, Rene S; Hald, Tine; Wegener, Henrik C

2011-12-01

In addition to medical antimicrobial usage, the use of antimicrobials in food animals contributes to the occurrence of resistance among some bacterial species isolated from infections in humans. Recently, several studies have indicated that a large proportion of Escherichia coli causing infections in humans, especially those resistant to antimicrobials, have an animal origin. We analyzed the correlation between the prevalence of antimicrobial resistance in E. coli isolates from blood stream infections in humans and in E. coli isolates from poultry, pigs, and cattle between 2005 and 2008 for 11 countries, using available surveillance data. We also assessed the correlation between human antimicrobial usage and the occurrence of resistance in E. coli isolates from blood stream infections. Strong and significant correlations between prevalences of resistance to ampicillin (r=0.94), aminoglycosides (r=0.72), third-generation cephalosporins (r=0.76), and fluoroquinolones (r=0.68) were observed for human and poultry E. coli isolates. Similar significant correlations were observed for ampicillin (r=0.91), aminoglycosides (r=0.73), and fluoroquinolone resistance (r=0.74) in pig and human isolates. In cattle isolates, only ampicillin resistance (r=0.72) was significantly correlated to human isolates. When usage of antimicrobials in humans was analyzed with antimicrobial resistance among human isolates, only correlations between fluoroquinolones (r=0.90) and third-generation cephalosporins (r=0.75) were significant. Resistance in E. coli isolates from food animals (especially poultry and pigs) was highly correlated with resistance in isolates from humans. This supports the hypothesis that a large proportion of resistant E. coli isolates causing blood stream infections in people may be derived from food sources.

Shigella Vulvovaginitis in Childhood: A Case Report

PubMed Central

Rajkumar, Solomon; Narayanaswamy, Geetha; Laude, Teresita Awa

1979-01-01

Vulvovaginitis due to Shigella sonnei is reported in a four-year-old child. Shigella sonnei as a rare primary pathogen causing vulvovaginitis, the prolonged nature of the clinical course, and the therapeutic implications of increasing resistance to ampicillin by the organism are discussed. PMID:395325

STUDIES ON THE USE OF AMPICILLIN-DEXTRIN AGAR ASAS AEROMONAS RECOVERY MEDIUM

EPA Science Inventory

The Contaminant Candidate List (CCL) includes the unregulated chemical and microbiological contaminants the EPA has identified as possibly posing a significant public risk to consumers if present in drinking water (1). There are three bacterial species listed in the CCL (Aeromon...

Multidrug-Resistant Bacterial Colonization of Combat-Injured Personnel at Admission to Medical Centers After Evacuation from Afghanistan and Iraq

DTIC Science & Technology

2011-07-01

Tobramycin -lactams Ampicillin/sulbactam Piperacillin/tazobactam Ceftazidime Cefepime Carbapenems Imipenem /cilastatin Meropenem Fluoroquinolones...patient-to-patient transmission in the acquisition of imipenem -resistant Pseudomonas Hospenthal et al. The Journal of TRAUMA® Injury, Infection, and

Prevalence and persistence of potentially pathogenic and antibiotic resistant bacteria during anaerobic digestion treatment of cattle manure.

PubMed

Resende, Juliana Alves; Silva, Vânia Lúcia; de Oliveira, Tamara Lopes Rocha; de Oliveira Fortunato, Samuel; da Costa Carneiro, Jailton; Otenio, Marcelo Henrique; Diniz, Cláudio Galuppo

2014-02-01

Anaerobic digestion figures as a sustainable alternative to avoid discharge of cattle manure in the environment, which results in biogas and biofertilizer. Persistence of potentially pathogenic and drug-resistant bacteria during anaerobic digestion of cattle manure was evaluated. Selective cultures were performed for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC). Antimicrobial susceptibility patterns were determined and a decay of all bacterial groups was observed after 60days. Multidrug-resistant bacteria were detected both the influent and effluent. GPC, the most prevalent group was highly resistant against penicillin and levofloxacin, whereas resistance to ampicillin, ampicillin-sulbactam and chloramphenicol was frequently observed in the ENT and NFR groups. The data point out the need of discussions to better address management of biodigesters and the implementation of sanitary and microbiological safe treatments of animal manures to avoid consequences to human, animal and environmental health. Copyright © 2013 Elsevier Ltd. All rights reserved.

Emerging organic contaminants in coastal waters: anthropogenic impact, environmental release and ecological risk.

PubMed

Jiang, Jheng-Jie; Lee, Chon-Lin; Fang, Meng-Der

2014-08-30

This study provides a first estimate of the sources, distribution, and risk presented by emerging organic contaminants (EOCs) in coastal waters off southwestern Taiwan. Ten illicit drugs, seven nonsteroidal anti-inflammatory drugs (NSAIDs), five antibiotics, two blood lipid regulators, two antiepileptic drugs, two UV filters, caffeine, atenolol, and omeprazole were analyzed by solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry (SPE-LC-MS/MS). Thirteen EOCs were detected in coastal waters, including four NSAIDs (acetaminophen, ibuprofen, ketoprofen, and codeine), three antibiotics (ampicillin, erythromycin, and cefalexin), three illicit drugs (ketamine, pseudoephedrine, and MDMA), caffeine, carbamazepine, and gemfibrozil. The median concentrations for the 13 EOCs ranged from 1.47 ng/L to 156 ng/L. Spatial variation in concentration of the 13 EOCs suggests discharge into coastal waters via ocean outfall pipes and rivers. Codeine and ampicillin have significant pollution risk quotients (RQ>1), indicating potentially high risk to aquatic organisms in coastal waters. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Inactivation and reactivation of antibiotic-resistant bacteria during and after UV disinfection in reclaimed water].

PubMed

Huang, Jing-Jing; Tang, Fang; Xi, Jin-Ying; Pang, Yu-Chen; Hu, Hong-Ying

2014-04-01

Prevalence of antibiotic-resistant bacteria in wastewater effluents is concerned as an emerging contaminant. To estimate inactivation and reactivation potentials of antibiotic-resistant bacteria by UV disinfection, inactivation and reactivation of penicillin-, ampicillin-, cephalexin-, chloramphenicol-and rifampicin-resistant bacteria in the secondary effluent were studied under different UV doses. The results showed that the inactivation ratios of penicillin-, ampicillin-, cephalexin-and chloramphenicol-resistant bacteria were higher than 4-log, which was closed to that of total heterotrophic bacteria; however, the inactivation ratio of rifampicin-resistant bacteria was lower (3.7-log) under 20 mJ x cm(-2) UV exposure. After 22 h standing incubation, antibiotic-resistant bacteria widely reactivated. The colony forming ability of antibiotic-resistant bacteria was as high as 3-log when exposed to 20 mJ x cm(-2) UV light. Hence, conventional UV dose can not effectively control reactivation of antibiotic-resistant bacteria in reclaimed water by UV disinfection.

Pleiotropic effects of polysaccharide capsule loss on selected biological properties of Streptococcus suis.

PubMed

Tanabe, Shin-Ichi; Bonifait, Laetitia; Fittipaldi, Nahuel; Grignon, Louis; Gottschalk, Marcelo; Grenier, Daniel

2010-01-01

In this study, an unencapsulated Streptococcus suis mutant was used to investigate the pleiotropic effects resulting from capsule loss. The capsule deficient mutant of S. suis acquired a biofilm-positive phenotype, which was associated with significantly increased cell surface hydrophobicity. Cell-associated fibrinogen-binding and chymotrypsin-like activities were decreased in the unencapsulated mutant. The mutant did not differ significantly from the encapsulated parent strain for minimal inhibitory concentrations to penicillin G, ampicillin, and tetracycline. However, while the encapsulated strain was highly resistant to the bactericidal action of penicillin G and ampicillin, the unencapsulated mutant was approximately 60-fold more sensitive. Compared with the parent strain, the unencapsulated mutant induced a much higher inflammatory response in monocyte-derived macrophages resulting in an increased secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and IL-8. The capsule appears to hinder important adhesins or hydrophobic molecules that mediate biofilm formation, as well as cell wall components capable of stimulating immune cells.

Pleiotropic effects of polysaccharide capsule loss on selected biological properties of Streptococcus suis

PubMed Central

Tanabe, Shin-Ichi; Bonifait, Laetitia; Fittipaldi, Nahuel; Grignon, Louis; Gottschalk, Marcelo; Grenier, Daniel

2010-01-01

In this study, an unencapsulated Streptococcus suis mutant was used to investigate the pleiotropic effects resulting from capsule loss. The capsule deficient mutant of S. suis acquired a biofilm-positive phenotype, which was associated with significantly increased cell surface hydrophobicity. Cell-associated fibrinogen-binding and chymotrypsin-like activities were decreased in the unencapsulated mutant. The mutant did not differ significantly from the encapsulated parent strain for minimal inhibitory concentrations to penicillin G, ampicillin, and tetracycline. However, while the encapsulated strain was highly resistant to the bactericidal action of penicillin G and ampicillin, the unencapsulated mutant was approximately 60-fold more sensitive. Compared with the parent strain, the unencapsulated mutant induced a much higher inflammatory response in monocyte-derived macrophages resulting in an increased secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8. The capsule appears to hinder important adhesins or hydrophobic molecules that mediate biofilm formation, as well as cell wall components capable of stimulating immune cells. PMID:20357962

Recurrent SDSE bacteraemia resulting in streptococcal toxic shock syndrome in a patient with Noonan syndrome.

PubMed

Suzuki, Kei; Nakamura, Akiko; Ishikura, Ken; Imai, Hiroshi

2016-08-02

A 19-year-old man with chronic lymphoedema due to Noonan syndrome presented at our hospital with septic shock and pain in his lower leg. Blood cultures were positive for Streptococcus dysgalactiae subsp equisimilis (SDSE), resulting in a diagnosis of cellulitis with toxic involvement. He was treated with ampicillin for 3 weeks. Although he did well for 6 weeks, septic shock recurred. Blood culture again revealed SDSE, with the strain being identical to the first episode, suggesting that this infection had relapsed. He was treated with ampicillin for 6 weeks and prophylactically with trimethoprim-sulfamethoxazole for 12 months. Although SDSE bacteraemia occurs commonly in elderly patients, findings in this patient showed that it can also develop in younger persons with predisposing factors. This case also indicates that SDSE has the potential to recur, despite generally sufficient antibiotic administration, and that patients who experience recurrent episodes may require prolonged treatment with antibiotics, including prophylaxis. 2016 BMJ Publishing Group Ltd.

[Augmentin in the clinical picture of infectious diseases].

PubMed

Gracheva, N M; Petrova, M S; Avakov, A A; Bobovnikova, V T

1992-09-01

Augmentin is a new combination manufactured by Smith Kline Beecham (Great Britain). It is composed of amoxycillin and clavulanic acid and has antibacterial activity. Augmentin was used in clinical trials in the therapy of 50 adult patients with suppurations after surgical operations on the organs of the abdominal cavity, general staphylococcal infections, pneumonia and prophylactically during the preoperative period. It was also used in the treatment of 30 children patients with bronchopulmonary affections and inflammatory otorhinolaryngological diseases. The clinical trials were performed in the Clinic of Infectious Diseases of the N. G. Gabrichevskiĭ Moscow Research Institute of Epidemiology and Microbiology. For comparison ampicillin was used in the trials. Augmentin was shown to be an efficient formulation with antibacterial activity which could be successfully used in the parenteral therapy of severe affections due to organisms sensitive to it. In the treatment of the children patients with pneumonia augmentin by its therapeutic efficacy proved to be superior to ampicillin. The tolerance of augmentin was good.

Antibiotic resistance of Escherichia coli isolated from a poultry slaughterhouse.

PubMed

Gregova, Gabriela; Kmetova, Marta; Kmet, Vladimfr; Venglovsky, Jan; Feher, Alexander

2012-01-01

The aim of the study was to investigate the antibiotic resistant E. coli strains isolated from bioaerosols and surface swabs in a slaughterhouse as a possible source of poultry meat contamination. The highest air coliforms contamination was during shackling, killing and evisceration of poultry. The strains showed resistance to ampicillin (89%), ceftiofur (62%) and cefquinome (22%), while resistance to ampicillin with sulbactam was only 6%. Resistance to streptomycin and gentamicin was detected in 43% vs. 14% isolates; to tetracycline 33%; to chloramphenicol and florfenicol in 10% vs. 18% isolates; to cotrimoxazol in 35% isolates; to enrofloxacin in 43% isolates. The higher MIC of ceftazidime (3.6 mg x l(-1)) and ceftriaxon (5.2 mg x l(-1)) revealed the presence of ESBLs in 43% of isolates. From 19 selected phenotypically ESBL positive strains, 16 consisted of CMY-2 genes, while CTX-M genes were not detected by PCR. Maldi tof analysis of selected E. coli showed a clear clonal relatedness of environmental strains from various withdrawals.

In Vitro Structural and Functional Evaluation of Gold Nanoparticles Conjugated Antibiotics

NASA Astrophysics Data System (ADS)

Saha, Biswarup; Bhattacharya, Jaydeep; Mukherjee, Ananda; Ghosh, Anup Kumar; Santra, Chitta Ranjan; Dasgupta, Anjan K.; Karmakar, Parimal

2007-12-01

Bactericidal efficacy of gold nanoparticles conjugated with ampicillin, streptomycin and kanamycin were evaluated. Gold nanoparticles (Gnps) were conjugated with the antibiotics during the synthesis of nanoparticles utilizing the combined reducing property of antibiotics and sodium borohydride. The conjugation of nanoparticles was confirmed by dynamic light scattering (DLS) and electron microscopic (EM) studies. Such Gnps conjugated antibiotics showed greater bactericidal activity in standard agar well diffusion assay. The minimal inhibitory concentration (MIC) values of all the three antibiotics along with their Gnps conjugated forms were determined in three bacterial strains, Escherichia coli DH5α, Micrococcus luteus and Staphylococcus aureus. Among them, streptomycin and kanamycin showed significant reduction in MIC values in their Gnps conjugated form whereas; Gnps conjugated ampicillin showed slight decrement in the MIC value compared to its free form. On the other hand, all of them showed more heat stability in their Gnps conjugated forms. Thus, our findings indicated that Gnps conjugated antibiotics are more efficient and might have significant therapeutic implications.

21 CFR 526.1130 - Hetacillin potassium for intramammary infusion.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hetacillin potassium for intramammary infusion... § 526.1130 Hetacillin potassium for intramammary infusion. (a) Specifications. Each 10 milliliter syringe contains hetacillin potassium equivalent of 62.5 milligrams of ampicillin. (b) Sponsor. See No...

21 CFR 526.1130 - Hetacillin potassium for intramammary infusion.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hetacillin potassium for intramammary infusion... § 526.1130 Hetacillin potassium for intramammary infusion. (a) Specifications. Each 10 milliliter syringe contains hetacillin potassium equivalent of 62.5 milligrams of ampicillin. (b) Sponsor. See No...

21 CFR 526.1130 - Hetacillin potassium for intramammary infusion.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hetacillin potassium for intramammary infusion... § 526.1130 Hetacillin potassium for intramammary infusion. (a) Specifications. Each 10 milliliter syringe contains hetacillin potassium equivalent of 62.5 milligrams of ampicillin. (b) Sponsor. See No...

Are biting fly larvae biological reservoirs of Salmonella?

USDA-ARS?s Scientific Manuscript database

A Salmonella Montevideo strain that is resistant to ampicillin and kanamycin and that expresses the green fluorescent protein (S Montevideo-GFP) was utilized to inoculate sterile and non-sterile cattle manure (1 x 105 CFU/gram manure) onto which sterilized horn fly embryos were placed and held for e...

Purification and properties of a beta-lactamase produced by Branhamella catarrhalis.

PubMed Central

Yokota, E; Fujii, T; Sato, K; Inoue, M; Mitsuhashi, S

1986-01-01

A beta-lactamase from Branhamella catarrhalis was purified by column chromatography. The purified enzyme hydrolyzed penicillins, such as ampicillin, carbenicillin, and piperacillin, more rapidly than cephalosporins. Furthermore, the enzyme hydrolyzed cefotaxime and cefmenoxime. The molecular weight of the enzyme was 33,000. The pI was 5.4. PMID:3486631

Deciphering the bacterial microbiome of citrus plants in response to ‘Candidatus Liberibacter asiaticus’-infection and antibiotic treatment

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB), the most devastating citrus disease worldwide, is vectored by phloem-feeding insects, and the pathogen in the USA is Candidatus Liberibacter asiaticus (Las). The bacterial microbiome of citrus after Las-infection and treatments with ampicillin (Amp) and gentamicin (Gm) was chara...

Acinetobacter baumannii in Human Body Louse

PubMed Central

Raoult, Didier

2004-01-01

While we were isolating Bartonella quintana from body lice, 40 Acinetobacter baumannii strains were also isolated and genotyped. One clone was unique and the other was ampicillin susceptible. A. baumannii DNA was later detected in 21% of 622 lice collected worldwide. These findings show an A. baumannii epidemic in human body lice. PMID:15498175

Occurrence of carbapenem-resistant Escherichia coli from wastewater in the United States: A retrospective analysis of isolates from 2005 (abstract)

EPA Science Inventory

E. coli isolates from primary and secondary effluents collected from seven WWTPs between 2003 and 2004 were recovered and then screened using one of four antibiotics (trimethoprim-sulfamethoxazole, ampicillin, tetracycline, and trimethoprim). We now report on the testing of a sub...

Occurrence of Carbapenem-Resistant Escherichia Coli from Wastewater in the United States: a Retrospective Analysis of Isolates from 2005

EPA Science Inventory

E. coli isolates from primary and secondary effluents collected from seven WWTPs between 2003 and 2004 were recovered and then screened using one of four antibiotics (trimethoprim-sulfamethoxazole, ampicillin, tetracycline, and trimethoprim). We now report on the testing of a sub...

Phytophthora species associated with tanoak stem cankers in southwestern Oregon

Treesearch

Paul Reeser; Wendy Sutton; Everett Hansen

2009-01-01

From 2001 through 2006 stem cankers on tanoak (Lithocarpus densiflorus) were sampled during surveys to detect and eradicate Phytophthora ramorum from forests in southwestern Oregon. Pieces of bark from stem canker margins were plated on cornmeal agar amended with 10 ppm natamycin, 200 ppm Na-ampicillin, and 10 ppm rifampicin....

Antibiotic Susceptibility of Neisseria gonorrhoeae Strains from Europe and Africa

PubMed Central

Piot, Peter; Van Dyck, Eddy; Colaert, Jan; Ursi, Jean-Paul; Bosmans, Eugène; Meheus, André

1979-01-01

The in vitro activities of 16 antimicrobial agents were tested by a plate dilution method against 268 unselected isolates of Neisseria gonorrhoeae from Belgium, Rwanda, Swaziland, and Zaire. Fifteen β-lactamase-producing strains isolated in Europe from various origins were also tested. There were significant regional variations in antimicrobial agent susceptibility, even among the African isolates, with the Rwandan and Zairean strains being most resistant. Benzylpenicillin and ampicillin were equally active in all but the β-lactamase-producing strains. Among the cephalosporins, cefotaxime was by far the most active, followed by cefuroxime, cefamandole, cefoxitin, and cefaclor, in that order. All strains were susceptible to spectinomycin, thiamphenicol, kanamycin, and rifampin, with the exception of one highly rifampin-resistant isolate and a moderately thiamphenicol-resistant strain. Twenty-six percent of the isolates were highly resistant to streptomycin. Six percent of the gonococci had a minimal inhibitory concentration for tetracycline greater than 2 μg/ml. Clavulanic acid inhibited the β-lactamase activity of the gonococci tested and improved markedly the activities of ampicillin and amoxicillin against β-lactamase-producing strains. PMID:111615

Quantitative analysis of amoxicillin, its major metabolites and ampicillin in eggs by liquid chromatography combined with electrospray ionization tandem mass spectrometry.

PubMed

Sun, Lirui; Jia, Longfei; Xie, Xing; Xie, Kaizhou; Wang, Jianfeng; Liu, Jianyu; Cui, Lulu; Zhang, Genxi; Dai, Guojun; Wang, Jinyu

2016-02-01

In this present study, we developed a simple, rapid and specific method for the quantitative analysis of the contents of amoxicillin (AMO), AMO metabolites and ampicillin (AMP) in eggs. This method uses a simple liquid-liquid extraction with acetonitrile followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The optimized method has been validated according to requirements defined by the European Union and Food and Drug Administration. Extraction recoveries of the target compounds from the egg at 5, 10 and 25 μg/kg were all higher than 80%, with relative standard deviations not exceeding 10.00%. The limits of quantification in eggs were below the maximum residue limits (MRLs). The decision limits (CCα) ranged between 11.1 and 11.5 μg/kg, while detection capabilities (CCβ) from 12.1 to 13.0 μg/kg. These values were very close to the corresponding MRLs. Finally, the new approach was successfully verified for the quantitative determination of these analytes in 40 commercial eggs from local supermarkets. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preterm premature ruptured membranes: a randomized trial of steroids after treatment with antibiotics.

PubMed

Lewis, D F; Brody, K; Edwards, M S; Brouillette, R M; Burlison, S; London, S N

1996-11-01

To assess the effectiveness of corticosteroids in patients with preterm premature rupture of membranes (PROM) after treatment with a broad-spectrum antibiotic, ampicillin-sulbactam. A randomized clinical trial of corticosteroids in patients with preterm PROM was undertaken after treating these patients for a minimum of 12 hours with ampicillin-sulbactam. No digital vaginal examinations were performed on these patients. Antibiotics were continued for 7 days and the steroids were repeated weekly. No tocolytics were used. The primary outcome measure was the incidence of respiratory distress syndrome (RDS). Secondary outcome measures included latency period and neonatal and maternal infectious morbidity. Seventy-seven patients were enrolled and data about their pregnancies were analyzed. No statistically significant difference in latency period was noted (14.7 days in the steroid group, 15.8 days in the no-steroid group). Both neonatal and maternal infectious morbidity were similar. A significant reduction in the incidence of RDS (18.4 versus 43.6%, P = .03) were observed in the steroid group. These data suggest that treating preterm PROM patients with a broad-spectrum antibiotic before corticosteroids decreases RDS without apparent adverse sequelae.

Lipopeptide biosurfactants from Paenibacillus polymyxa inhibit single and mixed species biofilms.

PubMed

Quinn, Gerry A; Maloy, Aaron P; McClean, Stephen; Carney, Brian; Slater, John W

2012-01-01

Although biofilms are recognised as important in microbial colonisation, solutions to their inhibition are predominantly based on planktonic assays. These solutions have limited efficacy against biofilms. Here, a series of biofilm-orientated tests were used to identify anti-biofilm compounds from marine micro-flora. This led to the isolation of a complex of anti-biofilm compounds from an extract of Paenibacillus polymyxa (PPE). A combination of rpHPLC and mass spectrometry identified the principle components of PPE as fusaricidin B (LI-FO4b) and polymyxin D1, with minor contributions from surfactins. This complex (PPE) reduced the biofilm biomass of Bacillus subtilis, Micrococcus luteus, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus bovis. In contrast, ampicillin was only effective against S. aureus. PPE also inhibited a self-assembling marine biofilm (SAMB) in co-incubation assays by 99.3% ± 1.9 and disrupted established SAMB by 72.4% ± 4.4, while ampicillin showed no significant reduction. The effectiveness of this complex of lipopeptides against single and multispecies biofilms suggests a future role in biofilm prevention strategies.

Antimicrobial Sensitivity of Avibacterium paragallinarum Isolates from Four Latin American Countries.

PubMed

Luna-Galaz, G A; Morales-Erasto, V; Peñuelas-Rivas, C G; Blackall, P J; Soriano-Vargas, E

2016-09-01

The antimicrobial sensitivity of 11 reference strains and 66 Avibacterium paragallinarum isolates from four Latin American countries was investigated. All 11 reference strains were sensitive to amoxicillin-clavulanic acid, ampicillin, fosfomycin, gentamicin, kanamycin, neomycin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole. The 11 reference strains were all resistant to lincomycin. All isolates (100%) from Mexico, Panama, and Peru were sensitive to amoxicillin-clavulanic acid, ampicillin, and fosfomycin. The Ecuadorian isolates showed some level of resistance to all 16 agents tested. The Ecuadorian isolates were significantly more sensitive to erythromycin, lincomycin, and streptomycin, and significantly more resistant to gentamicin, kanamycin, penicillin, and tetracycline, than the Mexican isolates. A total of 57.5% (38/66) of tested isolates were multi-drug resistant (MDR), with 16 MDR patterns detected in 88.4% (23/26) of the antimicrobial-resistant isolates from Ecuador, and 8 MDR patterns detected in 42.8% (15/35) of the antimicrobial-resistant isolates from Mexico. In conclusion, the variation in antimicrobial sensitivity patterns between isolates from Ecuador and Mexico emphasizes the importance of active, ongoing monitoring of A. paragallinarum isolates.

Genetic relatedness of a rarely isolated Salmonella: Salmonella enterica serotype Niakhar from NARMS animal isolates.

PubMed

Tankson, J D; Fedorka-Cray, P J; Jackson, C R; Headrick, M

2006-02-01

In the United States, Salmonella enterica serotype Niakhar is infrequently isolated. Between 1997 and 2000, the animal arm of the National Antimicrobial Resistance Monitoring System-Enteric Bacteria (NARMS) assayed a total of 22,383 Salmonella isolates from various animal sources (swine, cattle, chickens, turkeys, cats, horses, exotics and dogs) for antimicrobial susceptibility. Isolates originated from diagnostic and non-diagnostic submissions. To study the phenotypic and genotypic characteristics of Salmonella Niakhar. Only five (0.02%) of the 22,383 isolates were identified as Salmonella Niakhar. Antimicrobial resistance testing indicated that three isolates were pan-susceptible, one isolate was resistant to ampicillin and one isolate was resistant to ampicillin, chloramphenicol, ciprofloxacin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline and trimethoprim/sulfamethoxazole. RAPD-PCR analysis, PFGE and ribotyping indicated that two pan-susceptible isolates were genetically similar, whereas the three remaining isolates were genetically different. The one Salmonella Niakhar isolate that was multiresistant harboured a class I integron, intI1 and two large plasmids. This study represents the first report of a ciprofloxacin-resistant Salmonella isolate from the animal arm of NARMS.

[Purulent meningitis due to flavobacterium meningosepticum in Cameroonian children].

PubMed

Kokindombo, P O; Nko'o Amvenne, S; Ndjitoyap Ndam, E C; Wouaffo Ndayo, M; Tangam Ouambo, T; Tietche, F; Foumbi, J; Borderon, J C; Laugier, J; Mbede, J

1991-09-01

Following a number of reports of purulent CSF specimens positive for Flavobacterium meningosepticum in pediatric patients in Yaoundé, a prospective study was carried out in the Department of Pediatrics of the Central Yaoundé Hospital from December 1988 through December 1989. The goals of this study were to determine the incidence of Flavobacterium meningosepticum among infants and children with purulent meningitis, to discover the origin of this pathogen, and to examine its susceptibility to antimicrobial agents. Flavobacterium meningosepticum (18.4% of cases) was second by order of incidence, after pneumococci (50%). Incidences were low for the other pathogens usually described in purulent meningitis (H. influenzae, meningococcus...). All the pneumococcus strains recovered were susceptible to ampicillin. In contrast, 21.43% of strains of Flavobacterium meningosepticum were resistant to both ampicillin and chloramphenicol (the combination currently used as first line therapy in the Department), and 14.25% of strains were resistant to cefotaxime. The origin of the Flavobacterium meningosepticum strains found remains to be discovered. The low incidence of H. influenzae deserves to be reevaluated over the next few years.

Septic abortion presenting as a right lower trapezius abscess secondary to Bacteroides fragilis bacteraemia.

PubMed

Yamanaka, Yusuke; Shimabukuro, Akira

2017-08-21

A 43-year-old Japanese woman was evaluated in the outpatient department for right shoulder pain and fever, which began 5 days earlier. MRI of the right shoulder revealed a high-intensity area deep in the right trapezius muscle. Aspiration revealed purulent fluid, and Gram staining of the fluid showed Gram-negative bacilli. The patient was also found to be profoundly anaemic and to have a positive urine pregnancy test. On admission, we initiated intravenous ampicillin-sulbactam and aztreonam. She underwent dilatation and curettage for septic abortion and surgical drainage of the right shoulder abscess. Bacteroides fragilis was isolated from the blood, uterine aspiration and abscess samples. On hospital day 4, a whole-body CT scan revealed no other abscesses, and ampicillin-sulbactam was continued for 28 days. The patient was discharged on hospital day 29. Gram staining is an important tool for evaluating infectious aetiologies. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

UPLC-MS/MS method for therapeutic drug monitoring of 10 antibiotics used in intensive care units.

PubMed

El-Najjar, Nahed; Hösl, Julian; Holzmann, Thomas; Jantsch, Jonathan; Gessner, André

2018-03-01

A large variation in the levels of different ß-lactams and other antibiotics used in critically ill patients has been documented. The aim of this study is to establish and validate a fast, ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous analysis of ten antibiotics (Meropenem, Cefepime, Ceftazidime, Piperacillin, Benzylpenicillin, Ampicillin, Flucloxacillin, Linezolid, and Sulfamethoxazole/Trimethoprim) in human plasma according to European Medicines Agency (EMA) guidelines. Protein precipitation with ice-cold methanol containing 9 isotopically labeled internal standards was used for sample clean up. Antibiotics were detected, following a 4-minute gradient separation, in multiple reactions monitoring (MRM) using API 4000 instrument equipped with electrospray source operating in positive ion mode. The lower limit of quantification was 0.1 mg/L for Meropenem, Ceftazidime, Piperacillin, Ampicillin, Flucloxacillin, and Sulfamethoxazole; 0.05 mg/L for Cefepime, Benzylpenicillin, and Trimethoprim; and 0.02 mg/L for Linezolid. The method proved to be precise and accurate and applicable for therapeutic drug monitoring and other pharmacokinetic studies. Copyright © 2017 John Wiley & Sons, Ltd.

Survey of Clostridium difficile in retail seafood in College Station, Texas.

PubMed

Norman, Keri N; Harvey, Roger B; Andrews, Kathleen; Hume, Michael E; Callaway, Todd R; Anderson, Robin C; Nisbet, David J

2014-01-01

The incidence and severity of disease associated with toxigenic Clostridium difficile have increased in hospitals in North America with the emergence of newer, more virulent strains. Toxigenic C. difficile has been isolated from food animals and retail meat with potential implications of transfer to humans. The objective of the present study was to investigate the prevalence of C. difficile in retail seafood from grocery stores in College Station, Texas. C. difficile was found in 4.5% (3/67) of shellfish and finfish samples. The positive samples included one each from fresh mussel, frozen salmon and frozen shrimp. The mussel and salmon isolates were characterized as toxinotype V and pulsed-field gel electrophoresis (PFGE) type-NAP7. The shrimp isolate was identified as toxinotype XII, but had an unknown PFGE type. Susceptibilities to 11 antimicrobial agents were identical for the mussel and salmon isolates and were sensitive to eight of 11 antimicrobials (including ampicillin) and intermediate to clindamycin. However, the shrimp isolate was resistant to clindamycin and ampicillin. This study demonstrates that seafood, like other food commodities, can be contaminated by C. difficile.

[Bacterial meningitis caused by beta-lactamase-negative, ampicillin-resistant nontypeable Haemophilus influenzae in a 1-year-old girl: a case report].

PubMed

Abe, Katsuaki; Hoshino, Tadashi; Imuta, Naoko; Nishi, Junichiro; Ishiwada, Naruhiko

2014-05-01

We present herein the case report of bacterial meningitis caused by nontypeable Haemophilus influenzae (NTHi) in a 1-year-7-month-old girl with no medically significant history. NTHi from cerebrospinal fluid (CSF) was the beta-lactamase non-producing ampicillin resistant strain (BLNAR). Some beta-lactams were administrated, but fever was prolonged. Finally, rifampicin seemed to be effective. In NTHi, compared with H. influenzae type b (Hib), the prevalence of BLNAR is high. Hence, complicated cases may increase in the near future if the use of the Hib vaccine becomes widespread, and meningitis caused by NTHi increases. It may be necessary to consider combination therapy or use of non-beta-lactams that have a different antimicrobial mechanism from beta-lactams. PCR analysis revealed the possibility that the CSF isolate lacked the P5 protein gene. Though deficiency of P5 fimbriae is known to reduce the affinity of NTHi for the human respiratory epithelium, determining whether P5 deficient NTHi induced meningitis will require further study.

The detection limits of antimicrobial agents in cow's milk by a simple Yoghurt Culture Test.

PubMed

Mohsenzadeh, M; Bahrainipour, A

2008-09-15

The aim of this study was to study performance of Yoghurt Culture Test (YCT) in the detection of antimicrobial residues in milk. For this purpose, the sensitivity of YCT for 15 antibiotics were determined. For each drug, 8 concentrations were tested. The detection limits of YCT at 2.5 h and 4 h incubation were determined (microg kg(-1)): 15 and 37.5, penicillin G; 4 and 5, ampicillin; 5 and 7.5, amoxycillin; 100 and 200, cephalexin; 80 and 100, cefazoline; 100 and 200, oxytetracycline; 500 and 100, chlortetracycline; 100 and 200, tetracycline; 150 and 200, doxycycline; 200 and 400, sulphadimidine; 500 and 1000, gentamycin; 1000 and 1500, spectinomycin; 400 and 500, erythromycin; 50 and 100, tylosin; 5000 and 10000, chloramphenicol. The YCT detection limits at 2.5 h incubation for ampicillin, cephalexin, tetracycline, oxytetracycline and tylosin are similar to those obtained as Maximum Residue Limit (MRL) according to Regulation 2377/90 EEC as set out by the European Union. In addition the detection limits of YCT for some antibiotics were lower than some of microbial inhibitor test.

[Mechanisms of beta-lactam and quinolone resistance in Haemophilus influenzae].

PubMed

Ubukata, Kimiko

2012-02-01

Haemophilus influenzae is one of the important pathogens causing respiratory tract infections, pneumonia, and meningitis. Genotypic(g) beta-lactamase-nonproducing ampicillin resistance (gBLNAR) H. influenzae has rapidly increased since 2000 years in Japan. The resistant percentage exceeded 60% in Hib isolates from meningitis in 2009. The affinity of beta-lactam antibiotics for penicillin-binding proteins-3 (PBP3) that involved in septal peptidoglycan synthesis deceased in the resistant strains. Three amino acid substitutions, Ser385Thr, Asn526Lys and Arg517His in PBP3 encoded by ftsI gene are especially responsible for beta-lactam resistance in the gBLNAR. Susceptibilities of cephalosporin agents including cefotaxime for gBLNAR were apparently decreased than the ampicillin and carbapenem antibiotics. Though fluoroquinolone resistant isolates are rare (< 1%) in H. influenzae, strains of levofloxacin and ciprofloxacin MIC with > or = 8 microg/mL were isolated from elderly patients with CAP. These strains possessed amino acid substitutions of Ser84Phe and Asp88Asn in GyrA and Glu88Lys in ParC. It is important to practice rapidly identification of these resistant strains at routine work.

Cloning of the nptII gene of Escherichia coli and construction of a recombinant strain harboring functional recA and nptII antibiotic resistance.

PubMed

Ghanem, S

2011-01-01

In an attempt to clone the ORF of the nptII gene of Escherichia coli K12 (ATCC 10798), two degenerate primers were designed based on the nptII sequence of its Tn5 transposon. The nptII ORF was placed under the control of the E. coli hybrid trc promoter, in the pKK388-1 vector, transformed into E. coli DH5α ΔrecA (recombinant, deficient strain). Transferred cells were tested for ampicillin, tetracycline, kanamycin, neomycin, geneticin, paromomycin, penicillin, and UV resistance. The neomycin phosphotransferase gene of E. coli was cloned successfully and conferred kanamycin, neomycin, geneticin, and paromomycin resistance to recombinant DH5α; this did not inhibit insertion of additional antibiotic resistance against ampicillin and tetracycline, meaning the trc promoter can express two different genes carried by two different plasmids harbored in the same cell. This resistance conferral process could be considered as an emulation of horizontal gene transfer occurring in nature and would be a useful tool for understanding mechanisms of evolution of multidrug-resistant strains.

In vitro activity of salicylamide derivatives against vancomycin-resistant enterococci.

PubMed

Pospisilova, Sarka; Michnova, Hana; Kauerova, Tereza; Pauk, Karel; Kollar, Peter; Vinsova, Jarmila; Imramovsky, Ales; Cizek, Alois; Jampilek, Josef

2018-07-01

A series of 13 salicylamide derivatives was assessed for antibacterial activity against three isolates of vancomycin-resistant Enterococcus faecalis (VRE) and Enterococcus faecalis ATCC 29212 as a quality standard. The minimum inhibitory concentration was determined by the broth microdilution method with subsequent subcultivation of aliquots to assess minimum bactericidal concentration. The growth kinetics was established by the time-kill assay. Ampicillin, ciprofloxacin, tetracycline and vancomycin were used as the reference antibacterial drugs. Three of the investigated compounds showed strong bacteriostatic activity against VRE (0.199-25 µM) comparable to or more potent than ampicillin and ciprofloxacin. In addition, these compounds were tested for synergistic effect with vancomycin, ciprofloxacin and tetracycline, while 5-chloro-2-hydroxy-N-[4-(trifluoromethyl)phenyl]benzamide showed the highest potency as well as synergistic activity with vancomycin against VRE 368. Screening of the cytotoxicity of the most effective compounds was performed using human monocytic leukemia THP-1 cells, and based on LD 50 values, it can be stated that the compounds have insignificant toxicity against human cells. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization of the oral absorption of several aminopenicillins: determination of intrinsic membrane absorption parameters in the rat intestine in situ

NASA Technical Reports Server (NTRS)

Sinko, P. J.; Amidon, G. L.

1992-01-01

The absorption mechanism of several penicillins was characterized using in situ single-pass intestinal perfusion in the rat. The intrinsic membrane parameters were determined using a modified boundary layer model (fitted value +/- S.E.): Jmax* = 11.78 +/- 1.88 mM, Km = 15.80 +/- 2.92 mM, Pm* = 0, Pc* = 0.75 +/- 0.04 for ampicillin; Jmax* = 0.044 +/- 0.018 mM, Km = 0.058 +/- 0.026 mM, Pm* = 0.558 +/- 0.051, Pc* = 0.757 +/- 0.088 for amoxicillin; and Jmax* = 16.30 +/- 3.40 mM, Km = 14.00 +/- 3.30 mM, Pm* = 0, Pc* = 1.14 +/- 0.05 for cyclacillin. All of the aminopenicillins studied demonstrated saturable absorption kinetics as indicated by their concentration-dependent wall permeabilities. Inhibition studies were performed to confirm the existence of a nonpassive absorption mechanism. The intrinsic wall permeability (Pw*) of 0.01 mM ampicillin was significantly lowered by 1 mM amoxicillin and the Pw* of 0.01 mM amoxicillin was reduced by 2 mM cephradine consistent with competitive inhibition.

Utility of surface enhanced Raman spectroscopy (SERS) for elucidation and simultaneous determination of some penicillins and penicilloic acid using hydroxylamine silver nanoparticles.

PubMed

El-Zahry, Marwa R; Refaat, Ibrahim H; Mohamed, Horria A; Rosenberg, Erwin; Lendl, Bernhard

2015-11-01

Elucidation and quantitative determination of some of commonly used penicillins (ampicillin, penicillin G and carbenicillin) in the presence of their main degradation product (penicilloic acid) were developed. Forced acidic and basic degradation processes were applied at different time intervals. The formed degradation products were elucidated and quantified using surface enhanced Raman spectroscopy (SERS). Silver nanoparticles (AgNPs) prepared by reduction of silver nitrate using hydroxylamine-HCl in alkaline medium were used as SERS substrate. The results obtained in SERS were confirmed by the application of LC/MS method. The concentration range was 100-600 ng/ml in case of the studied penicillins and 100-700 ng/ml in case of penicilloic acid. An excellent correlation coefficient was found in case of ampicillin (r=0.9993) and in the case of penicilloic acid (r=0.9997). Validation procedures were carried out including precision, robustness and accuracy by comparing F- and t-values of both the proposed and reported methods. Copyright © 2015 Elsevier B.V. All rights reserved.

Semisynthetic Penicillin 6-[d(—)-α-Carboxy-3-Thienylacetamido] Penicillanic Acid Active Against Pseudomonas In Vitro

PubMed Central

Neu, H. C.; Winshell, E. B.

1971-01-01

The activity of 6-[d(—)-α-carboxy-3-thienylacetamido] penicillanic acid, BRL2288, was determined against Pseudomonas aeruginosa and various gram-negative bacilli. The majority of Pseudomonas strains (89%) were inhibited by 100 μg of the antibiotic per ml. BRL2288 is twofold more active than carbenicillin against Pseudomonas at 100 μg/ml or less. Among Enterobacteriaceae tested, 87% Enterobacter and 87% of Proteus mirabilis strains were inhibited by 25 μg/ml or less. Indole-positive Proteus were inhibited by 10 μg/ml or less. Fifty-five per cent of ampicillin-resistant Escherichia coli were inhibited by 100 μg/ml. Klebsiella were uniformly resistant. BRL2288 is not hydrolyzed by most resistant Pseudomonas, but it is destroyed by the β-lactamases of E. coli and P. mirabilis. The antibiotic shows synergy with gentamicin but not with penicillinase-resistant penicillins such as cloxacillin. Activity of BRL2288 against gram-positive organisms is two- to eightfold less than that of ampicillin or benzylpenicillin G. PMID:4993233

Containing antibiotic resistance: decreased antibiotic-resistant coliform urinary tract infections with reduction in antibiotic prescribing by general practices

PubMed Central

Butler, Chris C; Dunstan, Frank; Heginbothom, Margaret; Mason, Brendan; Roberts, Zoë; Hillier, Sharon; Howe, Robin; Palmer, Stephen; Howard, Anthony

2007-01-01

Background GPs are urged to prescribe antibiotics less frequently, despite lack of evidence linking reduced antibiotic prescribing with reductions in resistance at a local level. Aim To investigate associations between changes in antibiotic dispensing and changes in antibiotic resistance at general-practice level. Design of study Seven-year study of dispensed antibiotics and antibiotic resistance in coliform isolates from urine samples routinely submitted from general practice. Setting General practices in Wales. Method Multilevel modelling of trends in resistance to ampicillin and trimethoprim, and changes in practice total antibiotic dispensing and amoxicillin and trimethoprim dispensing. Results The primary analysis included data on 164 225 coliform isolates from urine samples submitted from 240 general practices over the 7-year study period. These practices served a population of 1.7 million patients. The quartile of practices that had the greatest decrease in total antibiotic dispensing demonstrated a 5.2% reduction in ampicillin resistance over the 7-year period with changes of 0.4%, 2.4%, and −0.3% in the other three quartiles. There was a statistically significant overall decrease in ampicillin resistance of 1.03% (95% confidence interval [CI] = 0.37 to 1.67%) per decrease of 50 amoxicillin items dispensed per 1000 patients per annum. There were also significant reductions in trimethoprim resistance in the two quartiles of practices that reduced total antibiotic dispensing most compared with those that reduced it least, with an overall decrease in trimethoprim resistance of 1.08% (95% CI = 0.065 to 2.10%) per decrease of 20 trimethoprim items dispensed per 1000 patients per annum. Main findings were confirmed by secondary analyses of 256 370 isolates from 527 practices that contributed data at some point during the study period. Conclusion Reducing antibiotic dispensing at general-practice level is associated with reduced local antibiotic resistance. These findings should further encourage clinicians and patients to use antibiotics conservatively. PMID:17925135

In vitro activity of RP 59500, a semisynthetic injectable pristinamycin, against staphylococci, streptococci, and enterococci.

PubMed Central

Fass, R J

1991-01-01

The in vitro activity of RP 59500, a semisynthetic pristinamycin, was compared with the activities of vancomycin, oxacillin, ampicillin, gentamicin, ciprofloxacin, and rifampin against five Staphylococcus species, five Streptococcus species, and four Enterococcus species. For staphylococci, MICs were 0.13 to 1 microgram/ml and the MICs for 90% of the strains tested (MIC90s) were 0.13 to 0.5 microgram/ml; there were no differences between oxacillin-susceptible and -resistant strains. For streptococci, MICs were 0.03 to 4 micrograms/ml and MIC90s were 0.25 to 2 micrograms/ml; viridans group streptococci were the least susceptible streptococci. For enterococci, MICs were 0.25 to 32 micrograms/ml and MIC90s were 2 to 4 micrograms/ml; Enterococcus faecalis was the least susceptible. Vancomycin was the only comparative drug with consistent activity against all species of gram-positive cocci. With RP 59500, raising the inoculum 100-fold, lowering the pH of cation-adjusted Mueller-Hinton broth to 5.5, or omitting cation supplementation had little effect on MICs, but 50% serum increased MICs 2 to 4 dilution steps. The differences between MBCs and MICs were greater for staphylococci and enterococci than for streptococci. Time-kill studies with 24 strains indicated that RP 59500 concentrations 2-, 4-, and 16-fold greater than the MICs usually killed bacteria of each species at similar rates; reductions in CFU per milliliter were less than those observed with oxacillin or vancomycin against staphylococci and less than those observed with ampicillin against enterococci. RP 59500 antagonized the bactericidal activities of oxacillin and gentamicin against Staphylococcus aureus ATCC 29213 and that of ampicillin against E. faecalis ATCC 29212. Against the latter, combination with gentamicin was indifferent. RP 59500 has a broad spectrum of in vitro activity against gram-positive cocci; combining it with other drugs is not advantageous. PMID:1903912

Empiric systemic antibiotics for hospitalized patients with severe odontogenic infections.

PubMed

Zirk, Matthias; Buller, Johannes; Goeddertz, Peter; Rothamel, Daniel; Dreiseidler, Timo; Zöller, Joachim E; Kreppel, Matthias

2016-08-01

Odontogenic infections may lead to severe head and neck infections with potentially great health risk. Age, location of purulent affected sites and beta-lactam allergy are some mentionable factors regarding patients' in-hospital stay and course of disease. Are there new challenges regarding bacteria' antibiotic resistance for empiric treatment and what influences do they have on patients' clinical course? We analyzed in a 4-year retrospective study the medical records of 294 in-hospital patients with severe odontogenic infections. On a routine base bacteria were identified and susceptibility testing was performed. Length of stay in-hospital was evaluated regarding patients' age, beta-lactam allergy profile, affected sites and bacteria susceptibility to empiric antibiotics. Length of stay in-hospital was detected to be associated with affected space and penicillin allergy as well (p < 0.05). Isolates presented large amounts of aerobic gram-positive bacteria (64.2%), followed by facultative anaerobic bacteria (gram+/15.8%, gram-/12.7%). Tested ampicillin in combination with sulbactam (or without) and cephalosporins displayed high susceptibility rates, revealing distinguished results regarding clindamycin (p < 0.05). Co-trimoxazol and moxifloxacin showed high overall susceptibility rates (MOX: 94.7%, COTRIM: 92.6%). This study demonstrates ampicillin/sulbactam in addition to surgical intervention is a good standard in treatment of severe odontogenic neck infections. Cephalosporins seem to be a considerable option as well. If beta-lactam allergy is diagnosed co-trimoxazol and moxifloxacin represent relevant alternatives. Age, allergic profile and bacteria' resistance patterns for empiric antibiotics have an influence on patients in-hospital stay. Ampicillin/sulbactam proves itself to be good for empiric antibiosis in severe odontogenic infections. Furthermore cephalosporins could be considered as another option in treatment. However moxifloxacin and co-trimoxazol deserves further investigation as empiric antibiosis in odontogenic infections if beta-lactam allergy is diagnosed. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Vaginal versus Obstetric Infection Escherichia coli Isolates among Pregnant Women: Antimicrobial Resistance and Genetic Virulence Profile.

PubMed

Sáez-López, Emma; Guiral, Elisabet; Fernández-Orth, Dietmar; Villanueva, Sonia; Goncé, Anna; López, Marta; Teixidó, Irene; Pericot, Anna; Figueras, Francesc; Palacio, Montse; Cobo, Teresa; Bosch, Jordi; Soto, Sara M

2016-01-01

Vaginal Escherichia coli colonization is related to obstetric infections and the consequent development of infections in newborns. Ampicillin resistance among E. coli strains is increasing, which is the main choice for treating empirically many obstetric and neonatal infections. Vaginal E. coli strains are very similar to extraintestinal pathogenic E. coli with regards to the virulence factors and the belonging to phylogroup B2. We studied the antimicrobial resistance and the genetic virulence profile of 82 E. coli isolates from 638 vaginal samples and 63 isolated from endometrial aspirate, placental and amniotic fluid samples from pregnant women with obstetric infections. The prevalence of E. coli in the vaginal samples was 13%, which was significant among women with associated risk factors during pregnancy, especially premature preterm rupture of membranes (p<0.0001). Sixty-five percent of the strains were ampicillin-resistant. The E. coli isolates causing obstetric infections showed higher resistance levels than vaginal isolates, particularly for gentamicin (p = 0.001). The most prevalent virulence factor genes were those related to the iron uptake systems revealing clear targets for interventions. More than 50% of the isolates belonged to the virulent B2 group possessing the highest number of virulence factor genes. The ampicillin-resistant isolates had high number of virulence factors primarily related to pathogenicity islands, and the remarkable gentamicin resistance in E. coli isolates from women presenting obstetric infections, the choice of the most appropriate empiric treatment and clinical management of pregnant women and neonates should be carefully made. Taking into account host-susceptibility, the heterogeneity of E. coli due to evolution over time and the geographical area, characterization of E. coli isolates colonizing the vagina and causing obstetric infections in different regions may help to develop interventions and avoid the aetiological link between maternal carriage and obstetric and subsequent puerperal infections.

Five-year assessment of causative agents and antibiotic resistances in urinary tract infections.

PubMed

Çoban, Bayram; Ülkü, Nesrin; Kaplan, Halit; Topal, Burhan; Erdoğan, Haluk; Baskın, Esra

2014-06-01

To show the distribution and changes of causative agents of urinary tract infections in children and resistance rates by years and select the most appropriate antibiotics. In this study, the Başkent University Alanya Research and Application Hospital automation system microbiology recording book was screened retrospectively. Growth of a single microorganism above 105 colonies (cfu/mL) was included in the assessment. Throughout the study, 10 691 urinary cultures were studies and growth was found in 392 (3.7%). Three hundred and nine (78.8%) of the samples with growth belonged to girls. Growth was found in the neonatal period in 32 patients (8.2%). The most commonly isolated microorganism was Escherichia coli (E. coli) which was found in 68.4% of the patients. Klebsiella spp. were found with a rate of 12.0%; Enterobacter spp. were found with a rate of 10.7% and proteus spp. were found with a rate of 5.1%. Resistance to cefalotin (62.1%), trimethoprim-sulfamethoxasole (43.1%), amoxycillin-clavulanate (34.8%), ampicillin (30.4%), cefixim (26.3%) and nitrofurantoin (3.6%) was found in E. coli species. The antibiotic which had the highest resistance rate was ampicillin with a rate of 93.2% for klebsiella and 83.4% for enterobacter. Klebsiella spp. were the most commonly grown pathogens in newborns (40.6%). In a follow-up period of 5 years, the resistance of E. coli to amoxycillin-clavulanate regressed from 40.3% to 31.3%, while the resistance to trimethoprim-sulfamethoxasole (TMP-SMX) regressed from 45.6% to 34.7%. A high resistance against first-generation cephalosporins, ampicillin, amoxycillin-clavulanate and TMP-SMX which are the first-line antibiotics in childhood urinary tract infections was found. Carbapenem (meropenem, imipenem) resistance was not found in our center. Nitrofurantoin, aminoglycosides and cefixime can be recommended for empirical treatment in our hospital because of low resistance. Antibiotic treatment should be redecided according to in vitro antibiotic sensitivity results.

Nasopharyngeal carriage and antimicrobial susceptibility of Haemophilus influenzae among children younger than 5 years of age in Beijing, China.

PubMed

Zhu, Hongbin; Wang, Aihua; Tong, Jingjing; Yuan, Lin; Gao, Wei; Shi, Wei; Yu, Sangjie; Yao, Kaihu; Yang, Yonghong

2015-02-04

Haemophilus influenzae is one of the main pathogens that cause community-acquired respiratory infections in children. Our previous study showed that H. influenzae is the second most common pathogen causing pneumonia and accounts for 30-50% of bacterial meningitis among Chinese children. H. influenzae carriage in children and its resistance to commonly used antimicrobials varies widely both geographically and over time. Surveys of the nasopharyngeal carriage of H. influenzae in children younger than 5 years of age with acute respiratory tract infection (ARI) were conducted in Beijing Children's Hospital, China in 2000, 2002, 2010, and 2012. The overall annual carriage rates of H. influenzae among children younger than 5 years of age with ARI were 35.5%, 20.6%, 14.4%, and 18.7%, and the percentages of H. influenzae isolates producing β-lactamase were 4%, 13%, 27.1%, and 31%, respectively. The percentages of susceptibility to ampicillin progressively decreased from 96% (2000) to 87% (2002) to 63% (2010) to 61% (2012). All of the ampicillin-resistant isolates were found to be beta-lactamase producers. The susceptibility to tetracycline increased from 54% (2000) to 60% (2002) to 91.5% (2010) to 94.5% (2012). No statistically significant differences were observed in the susceptibility to cefaclor, cefuroxime, sulfamethoxazole, and chloramphenicol. Amoxicillin/clavulanic acid and ceftriaxone were the most effective antimicrobials for the isolates of H. influenzae across the 10-year period. This report on the H. influenzae carriage rates in children and the susceptibility of these bacteria to commonly used antibiotics showed that H. influenzae carriage decreased from 2000 to 2012. Additionally, the percentage of β-lactamase-producing isolates increased while their susceptibility to ampicillin progressively decreased during this time. These results indicate that the appropriate empirical antimicrobial therapy should be changed for pediatric patients in China.

Epidemic and virulence characteristic of Shigella spp. with extended-spectrum cephalosporin resistance in Xiaoshan District, Hangzhou, China

PubMed Central

2014-01-01

Background Shigellae have become increasingly resistant to the extended-spectrum cephalosporin (ESC) worldwide and pose a great challenge to anti-infection treatment options. The purpose of this study was to determine the resistance, cephalosporin resistance mechanisms, virulence characteristic and genotype of ESC-resistant Shigella. Methods From 2008 to 2012, Shigella isolates collected from diarrhea patients were detected for antibiotics sensitivity by disk diffusion, cephalosporin resistance determinants and virulence genes using polymerase chain reaction (PCR) and genotyping through enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR). Results A total of 356 Shigella isolates were gathered, and 198 (55.6%, 58 S. flexneri and 140 S. sonnei) were resistant to ESC. All ESC-resistant isolates were susceptible to imipenem, and only 0.5% isolate was resistant to piperacillin/tazobactam. ESC-resistant S. flexneri showed high degrees of resistance to ampicillin (100%), ampicillin/sulbactam (96.6%), piperacillin (100%), trimethoprim/sulfamethoxazole (74.1%), ciprofloxacin (74.1%), levofloxacin (53.4%), ceftazidime (58.6%) and cefepime (58.6%). ESC-resistant S. sonnei exhibited high resistance rates to ampicillin (100%), piperacillin (100%) and trimethoprim/sulfamethoxazole (96.4%). Cephalosporin resistance genes were confirmed in 184 ESC-resistant isolates. blaCTX-M types (91.8%, mainly blaCTX-M-14, blaCTX-M-15 and blaCTX-M-57) were most prevalent, followed by blaOXA-30 (26.3%). Over 99.0% ESC-resistant isolates harbored virulence genes ial, ipaH, virA and sen. However, set1 were more prevalent in ESC-resistant S. flexneri isolates than in S. sonnei isolates. ERIC-PCR results showed that 2 and 3 main genotypes were detected in ESC-resistant S. flexneri and S. sonnei, respectively. Conclusion Our findings indicated that a high prevalence of ESC-resistant Shigella mediated mainly by blaCTX-M with stronger resistance and virulence, and the existence of specific clones responsible for these Shigella infection in the region studied. PMID:24886028

Epidemic and virulence characteristic of Shigella spp. with extended-spectrum cephalosporin resistance in Xiaoshan District, Hangzhou, China.

PubMed

Zhang, Chuan-Ling; Liu, Qing-Zhong; Wang, Juan; Chu, Xu; Shen, Li-Meng; Guo, Yuan-Yu

2014-05-15

Shigellae have become increasingly resistant to the extended-spectrum cephalosporin (ESC) worldwide and pose a great challenge to anti-infection treatment options. The purpose of this study was to determine the resistance, cephalosporin resistance mechanisms, virulence characteristic and genotype of ESC-resistant Shigella. From 2008 to 2012, Shigella isolates collected from diarrhea patients were detected for antibiotics sensitivity by disk diffusion, cephalosporin resistance determinants and virulence genes using polymerase chain reaction (PCR) and genotyping through enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR). A total of 356 Shigella isolates were gathered, and 198 (55.6%, 58 S. flexneri and 140 S. sonnei) were resistant to ESC. All ESC-resistant isolates were susceptible to imipenem, and only 0.5% isolate was resistant to piperacillin/tazobactam. ESC-resistant S. flexneri showed high degrees of resistance to ampicillin (100%), ampicillin/sulbactam (96.6%), piperacillin (100%), trimethoprim/sulfamethoxazole (74.1%), ciprofloxacin (74.1%), levofloxacin (53.4%), ceftazidime (58.6%) and cefepime (58.6%). ESC-resistant S. sonnei exhibited high resistance rates to ampicillin (100%), piperacillin (100%) and trimethoprim/sulfamethoxazole (96.4%). Cephalosporin resistance genes were confirmed in 184 ESC-resistant isolates. bla(CTX-M) types (91.8%, mainly bla(CTX-M-14), bla(CTX-M-15) and bla(CTX-M-57)) were most prevalent, followed by bla(OXA-30) (26.3%). Over 99.0% ESC-resistant isolates harbored virulence genes ial, ipaH, virA and sen. However, set1 were more prevalent in ESC-resistant S. flexneri isolates than in S. sonnei isolates. ERIC-PCR results showed that 2 and 3 main genotypes were detected in ESC-resistant S. flexneri and S. sonnei, respectively. Our findings indicated that a high prevalence of ESC-resistant Shigella mediated mainly by bla(CTX-M) with stronger resistance and virulence, and the existence of specific clones responsible for these Shigella infection in the region studied.

Epidemiological Features and Antibiotic Resistance Patterns of Haemophilus influenzae Originating from Respiratory Tract and Vaginal Specimens in Pediatric Patients.

PubMed

Li, Jian-Ping; Hua, Chun-Zhen; Sun, Li-Ying; Wang, Hong-Jiao; Chen, Zhi-Min; Shang, Shi-Qiang

2017-12-01

Haemophilus influenzae (H. influenzae) is a common pathogen of respiratory tract infections in children, however, as a possible cause of vulvovaginitis in prepubertal girls, its epidemiological features, antibiotic-resistance patterns, and treatment are seldom noted. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Specimens obtained from patients were inoculated on Haemophilus selective medium; and drug-sensitivities tests were determined using the disk diffusion method. A cefinase disk was used to detect β-lactamase. A total of 610 H. influenzae strains, 81.6% (498/610) from the respiratory tract and 18.0% (110/610) from the vagina, were identified in the Children's Hospital in 2015. The age of the children with respiratory tract strains were significantly younger than those with vaginal strains (P < .001). The H. influenzae isolation rate in May was the highest. The β-lactamase positive rate was 51.5% (314/610), and 52.5% (320/610) were resistant to ampicillin. The susceptibilities rates to cefuroxime, ampicillin/sulbactam, cefotaxime, clarithromycin, and sulfamethoxazole-trimethoprim were 72.1% (440/610), 95.9%, 96.4% (588/610), 81.8% (499/610), and 36.4% (222/610), respectively. Higher resistance to ampicillin, cefuroxime, clarithromycin, and sulfamethoxazole-trimethoprim were found in respiratory tract strains, compared with vaginal strains (P < .05). All of the patients with H. influenzae in the respiratory tract were cured with oral or intravenous β-lactam antibiotics. Of all patients with vaginal strains, 50% (55/110) were cured with topical ofloxacin gel, and 44.5% (49/110) were cured with oral β-lactam antibiotics. The drug-resistance rates of H. influenzae isolated from vagina were lower than those from the respiratory tract. Topical ofloxacin gel or oral β-lactam antibiotics are effective treatments to eliminate the H. influenza causing infection in the vagina. Copyright © 2017 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Feeding bovine milks with low or high IgA levels is associated with altered re-establishment of murine intestinal microbiota after antibiotic treatment

PubMed Central

Young, Wayne; Cakebread, Julie A.; Haigh, Brendan J.

2016-01-01

Antibiotics are a vital and commonly used therapeutic tool, but their use also results in profound changes in the intestinal microbiota that can, in turn, have significant health consequences. Understanding how the microbiota recovers after antibiotic treatment will help to devise strategies for mitigating the adverse effects of antibiotics. Using a mouse model, we have characterized the changes occurring in the intestinal microbiota immediately after five days exposure to ampicillin, and then at three and fourteen days thereafter. During the fourteen day period of antibiotic recovery, groups of mice were fed either water, cows’ milk containing high levels of IgA, or cows’ milk containing low levels of IgA as their sole source of liquid. Effects on microbiota of feeding milks for 14 days were also assessed in groups of mice that had no ampicillin exposure. Changes in microbiota were measured by high throughput sequencing of the V4 to V6 variable regions of the 16S ribosomal RNA gene. As expected, exposure to ampicillin led to profound changes to the types and abundance of bacteria present, along with a loss of diversity. At 14 days following antibiotic exposure, mice fed water had recovered microbiota compositions similar to that prior to antibiotics. However, feeding High-IgA milk to mice that has been exposed to antibiotics was associated with altered microbiota compositions, including increased relative abundance of Lactobacillus and Barnesiella compared to the start of the study. Mice exposed to antibiotics then fed Low-IgA milk also showed increased Barnesiella at day 14. Mice without antibiotic perturbation, showed no change in their microbiota after 14 days of milk feeding. Overall, these findings add to a knowledge platform for optimizing intestinal function after treatment with antibiotics in the human population. PMID:27703861

Use of natural antimicrobials to increase antibiotic susceptibility of drug resistant bacteria.

PubMed

Palaniappan, Kavitha; Holley, Richard A

2010-06-15

Plant-derived antibacterial compounds may be of value as a novel means for controlling antibiotic resistant zoonotic pathogens which contaminate food animals and their products. Individual activity of natural antimicrobials (eugenol, thymol, carvacrol, cinnamaldehyde, allyl isothiocyanate (AIT)) and activity when paired with an antibiotic was studied using broth microdilution and checkerboard methods. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interactions between the inhibitors. Bacteria tested were chosen because of their resistance to at least one antibiotic which had a known genetic basis. Substantial susceptibility of these bacteria toward the natural antimicrobials and a considerable reduction in the minimum inhibitory concentrations (MIC's) of the antibiotics were noted when paired combinations of antimicrobial and antibiotic were used. In the interaction study, thymol and carvacrol were found to be highly effective in reducing the resistance of Salmonella Typhimurium SGI 1 (tet A) to ampicillin, tetracycline, penicillin, bacitracin, erythromycin and novobiocin (FIC<0.4) and resistance of Streptococcus pyogenes ermB to erythromycin (FIC<0.5). With Escherichia coli N00 666, thymol and cinnamaldehyde were found to have a similar effect (FIC<0.4) in reducing the MIC's of ampicillin, tetracycline, penicillin, erythromycin and novobiocin. Carvacrol, thymol (FIC<0.3) and cinnamaldehyde (FIC<0.4) were effective against Staphylococcus aureus blaZ and in reducing the MIC's of ampicillin, penicillin and bacitracin. Allyl isothiocyanate (AIT) was effective in reducing the MIC of erythromycin (FIC<0.3) when tested against S. pyogenes. Fewer combinations were found to be synergistic when the decrease in viable population (log DP) was calculated. Together, fractional inhibitory concentrations < or = 0.5 and log DP<-1 indicated synergistic action between four natural antimicrobials and as many as three antibiotics to which these bacteria were normally resistant. Copyright 2010 Elsevier B.V. All rights reserved.

Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP

NASA Astrophysics Data System (ADS)

Czulak, J.; Guerreiro, A.; Metran, K.; Canfarotta, F.; Goddard, A.; Cowan, R. H.; Trochimczuk, A. W.; Piletsky, S.

2016-05-01

Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates.Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates. Electronic supplementary information (ESI) available: Additional circular dichroism data and nanoparticle tracking analysis trace. See DOI: 10.1039/c6nr02009g

Antimicrobial resistance profile of Enterococcus spp isolated from food in Southern Brazil

PubMed Central

Riboldi, Gustavo Pelicioli; Frazzon, Jeverson; d’Azevedo, Pedro Alves; Frazzon, Ana Paula Guedes

2009-01-01

Fifty-six Enterococcus spp. strains were isolated from foods in Southern Brazil, confirmed by PCR and classified as Enterococcus faecalis (27), Enterococcus faecium (23) and Enterococcus spp (6). Antimicrobial susceptibility tests showed resistance phenotypes to a range of antibiotics widely administrated in humans such as gentamycin, streptomycin, ampicillin and vancomycin. PMID:24031330

Annual Progress Report (SEATO Medical Research Laboratory)

DTIC Science & Technology

1975-03-01

Vibrio porahemolyticus Infection in Thailand . 105 Cholera Study at Samutsongkram . . . . .. 110 Detection of Specific Bacterial Antigen by...clinical picture of the mild form of the disease needs to be described. Dehydration was not as severe as that seen in infection with Vibrio cholera ...co-trimoxazole, neomycin, erythromycin and streptomycin. Only 6 , and 62 % of the vibrios tested were sensitive to ampicillin and colistin

Phytophthora species associated with stem cankers on tanoak in southwestern Oregon

Treesearch

Paul Reeser; Wendy Sutton; Everett Hansen

2008-01-01

In effort to eradicate Phytophthora ramorum from Oregon forests, tanoak over its entire range in southwestern Oregon is surveyed intensively for stem disease. Pieces of bark from the leading edge of tanoak stem cankers were plated on cornmeal agar amended with 10 ppm natamycin, 200 ppm a-ampicillin, and 10 ppm rifamycin SV (CARP) to favor the...

Drug-susceptibility of isolates of Brachyspira hyodysenteriae isolated from colonic mucosal specimens of pigs collected from slaughter houses in Japan in 2009

PubMed Central

KAJIWARA, Keita; KOZAWA, Midori; KANAZAWA, Takuya; UETSUKA, Kouji; NAKAJIMA, Hiromi; ADACHI, Yoshikazu

2015-01-01

Twenty nine isolates identified as Brachyspira hyodysenteriae were most susceptible to carbadox and metronidazole, whereas they were resistant to macrolides. The isolates showed intermediate susceptibility to tiamulin, lincomycin, penicillin G, ampicillin, chloramphenicol, tetracycline, enrofloxacin and valnemulin, with MIC50 values ranging from 0.39 to 3.13. PMID:26596637

Impact of Acinetobacter infection on the Mortality of Burn Patients

DTIC Science & Technology

2006-10-01

associated with in- creased mortality (Table 3). Most of the Acb isolates seen were resistant to a broad range of antimicrobials (Table 4). Imipenem ...infected patients received effec- tive therapy, as defined previously. The majority of these patients (32) received imipenem -cilastatin. Other...Antimicrobial % of isolates susceptible Imipenem 61 Amikacin 36 Ampicillin-sulbactam (n 58) 24 Tobramycin 22 Piperacillin-tazobactam 14

[Microbiological characterization of non-O1 Vibrio cholerae isolated in Cuba].

PubMed

Bravo Fariñas, Laura; Fernández, Anabel; Ramírez, María M; Llop, Alina; Martínez, Gerardo; Hernández, Raquel I; Cabrera, Luis E; Morier, Luis; Fraga, Jorge; Núñez, Fidel A; Aguila, Adalberto

2007-01-01

The study of 422 non-01 Vibrio cholerae strains from nine provinces, 9 of them isolated from a water-borne disease outbreak, was performed. All the strains exhibited antimicrobial susceptibility and virulence factors. The nine strains from the outbreak were subjected to a DNA macrorestriction study based on the pulsed field electrophoresis technique. For the first time in Cuba and the Caribbean. The circulation of atypical non-01 V cholerae strains (resistent to vibriostatic compound 0129 and trimethoprim/sulfamethoxazole). The behavior of antimicrobial susceptibility evinced for the first time the circulation of two different resistence patterns in Cuba (ampicilline, trimethoprim/ sulfamethoxazole, sulfonamide and tetracycline, trimethoprim/ sulfamethoxazole, sulfonamide). The frequency of trimethoprim/ sulfamethoxazole-resistent strains was similar during the whole period of study. However, resistance to ampicilline decreased whereas resistance to tetracycline increased. The main found virulence factors were gelatinase, hemolysine, elastase and adherence to Hep-2 cells. On the other hand, the outbreak strains showed higher percentages than the others due to the presence of heat-liable toxin and fimbriae. The results of the molecular and epidemiological studies allowed giving a speedy and accurate response that explained the etiology of the first food-borne disease outbreak.

Seminal Corynebacterium strains in infertile men with and without leucocytospermia.

PubMed

Mashaly, M; Masallat, D T; Elkholy, A A; Abdel-Hamid, I A; Mostafa, T

2016-04-01

This study aimed to identify seminal Corynebacterium strains in infertile men with and without leucocytospermia. Semen samples from 60 infertile men were allocated into two equal groups: semen samples with leucocytospermia and semen samples without leucocytospermia. Semen culture for Corynebacterium species was carried out on Columbia agar medium confirmed by Gram-stained film and biochemical tests followed by analytical profile index biotyping and antibiotic susceptibility. Bacterial isolates were detected in 20/60 semen cultures (33.3%) as Corynebacteria, Staphylococci, Alpha haemolytic streptococci and E. coli. In all, 12/60 (20%) had Corynebacterium positive semen culture, whereas C. seminal was the major isolated species followed by C. amycolatum, C. jekium and C. urealyticum. There was nonsignificant difference between patients with/without Corynebacterium positive culture regarding sperm concentration and normal sperm morphology; however, in positive cultures sperm motility was significantly lower compared with negative cultures. Antimicrobial sensitivity among Corynebacteria strains was highest for vancomycin, rifampicin then imipenem, ampicillin + sulbactam, ciprofloxacin. It is concluded that positive semen cultures for different Corynebacteria species were demonstrated in infertile men, whereas Corynebacterium seminale was the most common isolated species. Vancomycin, rifampicin then imipenem and ampicillin + sulbactam are recommended as sensitive antibiotics. © 2015 Blackwell Verlag GmbH.

Prebiotics Modulate the Effects of Antibiotics on Gut Microbial Diversity and Functioning in Vitro.

PubMed

Johnson, Laura P; Walton, Gemma E; Psichas, Arianna; Frost, Gary S; Gibson, Glenn R; Barraclough, Timothy G

2015-06-04

Intestinal bacteria carry out many fundamental roles, such as the fermentation of non-digestible dietary carbohydrates to produce short chain fatty acids (SCFAs), which can affect host energy levels and gut hormone regulation. Understanding how to manage this ecosystem to improve human health is an important but challenging goal. Antibiotics are the front line of defence against pathogens, but in turn they have adverse effects on indigenous microbial diversity and function. Here, we have investigated whether dietary supplementation--another method used to modulate gut composition and function--could be used to ameliorate the side effects of antibiotics. We perturbed gut bacterial communities with gentamicin and ampicillin in anaerobic batch cultures in vitro. Cultures were supplemented with either pectin (a non-fermentable fibre), inulin (a commonly used prebiotic that promotes the growth of beneficial bacteria) or neither. Although antibiotics often negated the beneficial effects of dietary supplementation, in some treatment combinations, notably ampicillin and inulin, dietary supplementation ameliorated the effects of antibiotics. There is therefore potential for using supplements to lessen the adverse effects of antibiotics. Further knowledge of such mechanisms could lead to better therapeutic manipulation of the human gut microbiota.

Free radicals properties of gamma-irradiated penicillin-derived antibiotics: piperacillin, ampicillin, and crystalline penicillin.

PubMed

Wilczyński, Sławomir; Pilawa, Barbara; Koprowski, Robert; Wróbel, Zygmunt; Ptaszkiewicz, Marta; Swakoń, Jan; Olko, Paweł

2014-03-01

The aim of this work was to determine the concentrations and properties of free radicals in piperacillin, ampicillin, and crystalline penicillin after gamma irradiation. The radicals were studied by electron paramagnetic resonance (EPR) spectroscopy using an X-band spectrometer (9.3 GHz). Gamma irradiation was performed at a dose of 25 kGy. One- and two-exponential functions were fitted to the experimental data, in order to assess the influence of the antibiotics' storage time on the measured EPR lines. After gamma irradiation, complex EPR lines were recorded confirming the presence of a large number of free radicals formed during the irradiation. For all tested antibiotics, concentrations of free radicals and parameters of EPR spectra changed with storage time. The results obtained demonstrate that concentration of free radicals and other spectroscopic parameters can be used to select the optimal parameters of radiation sterilization of β-lactam antibiotics. The most important parameters are the constants τ (τ (1(A),(I)) and τ (2(A),(I))) and K (K (0(A),(I)), K (1(A),(I)), K (2(A),(I))) of the exponential functions that describe free radicals decay during samples storage.

Antimicrobial Susceptibility of Escherichia coli Isolated from Fresh-Marketed Nile Tilapia (Oreochromis niloticus)

PubMed Central

Rocha, Rafael dos Santos; Leite, Lana Oliveira; de Sousa, Oscarina Viana; Vieira, Regine Helena Silva dos Fernandes

2014-01-01

The contamination of seafood by bacteria of fecal origin, especially Escherichia coli, is a widely documented sanitary problem. The objective of the present study was to isolate E. coli strains from the gills, muscle, and body surface of farmed Nile tilapias (Oreochromis niloticus) fresh-marketed in supermarkets in Fortaleza (Ceará, Brazil), to determine their susceptibility to antibiotics of different families (amikacin, gentamicin, imipenem, cephalothin, cefotaxime, ciprofloxacin, aztreonam, ampicillin, nalidixic acid, tetracycline, and sulfametoxazol-trimetoprim), and to determine the nature of resistance by plasmid curing. Forty-four strains (body surface = 25, gills = 15, muscle = 4) were isolated, all of which were susceptible to amikacin, aztreonam, cefotaxime, ciprofloxacin, gentamicin, and imipenem. Gill and body surface samples yielded 11 isolates resistant to ampicillin, tetracycline, and sulfametoxazol-trimetoprim, 4 of which of plasmidial nature. The multiple antibiotic resistance index was higher for strains isolated from body surface than from gills. The overall high antibiotic susceptibility of E. coli strains isolated from fresh-marketed tilapia was satisfactory, although the occasional finding of plasmidial resistance points to the need for close microbiological surveillance of the farming, handling, and marketing conditions of aquaculture products. PMID:24808957

Astrobiology as a framework for investigating antibiotic susceptibility: a study of Halomonas hydrothermalis

PubMed Central

Cockell, Charles S.

2017-01-01

Physical and chemical boundaries for microbial multiplication on Earth are strongly influenced by interactions between environmental extremes. However, little is known about how interactions between multiple stress parameters affect the sensitivity of microorganisms to antibiotics. Here, we assessed how 12 distinct permutations of salinity, availability of an essential nutrient (iron) and atmospheric composition (aerobic or microaerobic) affect the susceptibility of a polyextremotolerant bacterium, Halomonas hydrothermalis, to ampicillin, kanamycin and ofloxacin. While salinity had a significant impact on sensitivity to all three antibiotics (as shown by turbidimetric analyses), the nature of this impact was modified by iron availability and the ambient gas composition, with differing effects observed for each compound. These two parameters were found to be of particular importance when considered in combination and, in the case of ampicillin, had a stronger combined influence on antibiotic tolerance than salinity. Our data show how investigating microbial responses to multiple extremes, which are more representative of natural habitats than single extremes, can improve our understanding of the effects of antimicrobial compounds and suggest how studies of habitability, motivated by the desire to map the limits of life, can be used to systematically assess the effectiveness of antibiotics. PMID:28123098

Modulation of release kinetics by plasma polymerization of ampicillin-loaded β-TCP ceramics

NASA Astrophysics Data System (ADS)

Labay, C.; Buxadera-Palomero, J.; Avilés, M.; Canal, C.; Ginebra, M. P.

2016-08-01

Beta-tricalcium phosphate (β-TCP) bioceramics are employed in bone repair surgery. Their local implantation in bone defects puts them in the limelight as potential materials for local drug delivery. However, obtaining suitable release patterns fitting the required therapeutics is a challenge. Here, plasma polymerization of ampicillin-loaded β-TCP is studied for the design of a novel antibiotic delivery system. Polyethylene glycol-like (PEG-like) coating of β-TCP by low pressure plasma polymerization was performed using diglyme as precursor, and nanometric PEG-like layers were obtained by simple and double plasma polymerization processes. A significant increase in hydrophobicity, and the presence of plasma polymer was visible on the surface by SEM and quantified by XPS. As a main consequence of the plasma polymerisation, the release kinetics were successfully modified, avoiding burst release, and slowing down the initial rate of release leading to a 4.5 h delay in reaching the same antibiotic release percentage, whilst conservation of the activity of the antibiotic was simultaneously maintained. Thus, plasma polymerisation on the surface of bioceramics may be a good strategy to design controlled drug delivery matrices for local bone therapies.

Astrobiology as a framework for investigating antibiotic susceptibility: a study of Halomonas hydrothermalis.

PubMed

Harrison, Jesse P; Angel, Roey; Cockell, Charles S

2017-01-01

Physical and chemical boundaries for microbial multiplication on Earth are strongly influenced by interactions between environmental extremes. However, little is known about how interactions between multiple stress parameters affect the sensitivity of microorganisms to antibiotics. Here, we assessed how 12 distinct permutations of salinity, availability of an essential nutrient (iron) and atmospheric composition (aerobic or microaerobic) affect the susceptibility of a polyextremotolerant bacterium, Halomonas hydrothermalis, to ampicillin, kanamycin and ofloxacin. While salinity had a significant impact on sensitivity to all three antibiotics (as shown by turbidimetric analyses), the nature of this impact was modified by iron availability and the ambient gas composition, with differing effects observed for each compound. These two parameters were found to be of particular importance when considered in combination and, in the case of ampicillin, had a stronger combined influence on antibiotic tolerance than salinity. Our data show how investigating microbial responses to multiple extremes, which are more representative of natural habitats than single extremes, can improve our understanding of the effects of antimicrobial compounds and suggest how studies of habitability, motivated by the desire to map the limits of life, can be used to systematically assess the effectiveness of antibiotics. © 2017 The Author(s).

Potential enterotoxicity and antimicrobial resistance pattern of Aeromonas species isolated from pet turtles and their environment.

PubMed

Wimalasena, S H M P; Shin, Gee-Wook; Hossain, Sabrina; Heo, Gang-Joon

2017-05-23

To investigate the potential enterotoxicity and antimicrobial resistance of aeromonads from pet turtles as a risk for human infection, one hundred and two Aeromonas spp. were isolated from the feces, skin and rearing environments of pet turtles and identified by biochemical and gyrB sequence analyses. Aeromonas enteropelogenes was the predominant species among the isolates (52.9%) followed by A. hydrophila (32.4%), A. dharkensis (5.9%), A. veronii (4.9%) and A. caviae (3.9%). Their potential enterotoxicities were evaluated by PCR assays for detecting genes encoding cytotoxic enterotoxin (act) and two cytotonic enterotoxins (alt and ast). 75.8% of A. hydrophila isolates exhibited the act + /alt + /ast + genotype, whereas 94.4% of A. enteropelogenes isolates were determined to be act - /alt - /ast - . In an antimicrobial susceptibility test, most isolates were susceptible to all tested antibiotics except amoxicillin, ampicillin, cephalothin, chloramphenicol and tetracycline. Non-susceptible isolates to penicillins (ampicillin and amoxicillin) and fluoroquinolones (ciprofloxacin and norfloxacin) were frequently observed among the A. enteropelogenes isolates. Few isolates were resistant to imipenem, amikacin, ceftriaxone and cefotaxime. Collectively, these results suggest that pet turtles may pose a public health risk of infection by enterotoxigenic and antimicrobial resistant Aeromonas strains.

Microbiology of Urinary Tract Infections in Gaborone, Botswana

PubMed Central

Renuart, Andrew J.; Goldfarb, David M.; Mokomane, Margaret; Tawanana, Ephraim O.; Narasimhamurthy, Mohan; Steenhoff, Andrew P.; Silverman, Jonathan A.

2013-01-01

Objective The microbiology and epidemiology of UTI pathogens are largely unknown in Botswana, a high prevalence HIV setting. Using laboratory data from the largest referral hospital and a private hospital, we describe the major pathogens causing UTI and their antimicrobial resistance patterns. Methods This retrospective study examined antimicrobial susceptibility data for urine samples collected at Princess Marina Hospital (PMH), Bokamoso Private Hospital (BPH), or one of their affiliated outpatient clinics. A urine sample was included in our dataset if it demonstrated pure growth of a single organism and accompanying antimicrobial susceptibility and subject demographic data were available. Results A total of 744 samples were included. Greater than 10% resistance was observed for amoxicillin, co-trimoxazole, amoxicillin-clavulanate, and ciprofloxacin. Resistance of E. coli isolates to ampicillin and co-trimoxazole was greater than 60% in all settings. HIV status did not significantly impact the microbiology of UTIs, but did impact antimicrobial resistance to co-trimoxazole. Conclusions Data suggests that antimicrobial resistance has already emerged to most oral antibiotics, making empiric management of outpatient UTIs challenging. Ampicillin, co-trimoxazole, and ciprofloxacin should not be used as empiric treatment for UTI in this context. Nitrofurantoin could be used for simple cystitis; aminoglycosides for uncomplicated UTI in inpatients. PMID:23469239

Microbiology of urinary tract infections in Gaborone, Botswana.

PubMed

Renuart, Andrew J; Goldfarb, David M; Mokomane, Margaret; Tawanana, Ephraim O; Narasimhamurthy, Mohan; Steenhoff, Andrew P; Silverman, Jonathan A

2013-01-01

The microbiology and epidemiology of UTI pathogens are largely unknown in Botswana, a high prevalence HIV setting. Using laboratory data from the largest referral hospital and a private hospital, we describe the major pathogens causing UTI and their antimicrobial resistance patterns. This retrospective study examined antimicrobial susceptibility data for urine samples collected at Princess Marina Hospital (PMH), Bokamoso Private Hospital (BPH), or one of their affiliated outpatient clinics. A urine sample was included in our dataset if it demonstrated pure growth of a single organism and accompanying antimicrobial susceptibility and subject demographic data were available. A total of 744 samples were included. Greater than 10% resistance was observed for amoxicillin, co-trimoxazole, amoxicillin-clavulanate, and ciprofloxacin. Resistance of E. coli isolates to ampicillin and co-trimoxazole was greater than 60% in all settings. HIV status did not significantly impact the microbiology of UTIs, but did impact antimicrobial resistance to co-trimoxazole. Data suggests that antimicrobial resistance has already emerged to most oral antibiotics, making empiric management of outpatient UTIs challenging. Ampicillin, co-trimoxazole, and ciprofloxacin should not be used as empiric treatment for UTI in this context. Nitrofurantoin could be used for simple cystitis; aminoglycosides for uncomplicated UTI in inpatients.

[Clinical efficacy of flomoxef in neonatal bacterial infection].

PubMed

Sakata, H; Hirano, Y; Maruyama, S

1993-03-01

One hundred and seventy one neonates were treated with flomoxef (FMOX) and the clinical efficacy and safety were evaluated. The ages of the patients ranged from 0 to 28 days, and their body weights from 450 to 4300 g. Dose levels were 12.4 to 24.9 mg/kg every 8 or 12 hours for 1 to 10 days. Fifty two patients who responded to the FMOX treatment included 5 neonates with sepsis, 17 with suspected sepsis, 9 with urinary tract infections, 12 with pneumonia, 8 with intrauterine infections, and 1 with omphalitis. The other neonates could not be retrospectively diagnosed as bacterial infections. Of 52 patients, clinical results were excellent in 15, good in 34, fair in 1, and poor in 2. And the FMOX treatment was effective in 13 out of 14 patients in which causative bacteria were identified. The drug was well tolerated, but 6 neonates out of 33 over 5 days old had diarrhea. From these results, empiric treatment with FMOX against neonatal bacterial infection was as clinically useful as that of combination with ampicillin and gentamicin or cefotaxime and ampicillin in our neonatal intensive care unit. But, as this study did not include neonate with meningitis, efficacy to meningitis was not evaluated.

In Vitro Activity of p-Hydroxybenzyl Penicillin (Penicillin X) and Five Other Penicillins Against Neisseria gonorrhoeae: Comparisons of Strains from Patients with Uncomplicated Infections and from Women with Pelvic Inflammatory Disease

PubMed Central

Sackel, Stephen G.; Alpert, Susan; Rosner, Bernard; McCormack, William M.; Finland, Maxwell

1977-01-01

Minimum inhibitory concentrations (MICs) of six penicillins against 95 strains of Neisseria gonorrhoeae from patients with uncomplicated anogenital infections and 22 strains from women with pelvic inflammatory disease were determined by an agar plate dilution method, using an inocula replicator. Against all 117 strains, the order of activity observed was: BL-P1654 > penicillin X > penicillin G > ampicillin > amoxicillin = carbenicillin. MICs against strains isolated from women with gonococcal pelvic inflammatory disease were significantly higher than those against isolates from uncomplicated infections: BL-P1654, P < 0.001; penicillin X, P < 0.001; penicillin G, P < 0.001; ampicillin, P < 0.001; and amoxicillin, P < 0.05. MICs of penicillin G were ≥0.125 μg/ml against 33 (36%) of the 92 strains from patients with uncomplicated infections, as contrasted with 15 (68%) of the 22 isolates from women with pelvic inflammatory disease (P < 0.01). The means of the MICs of penicillin G were 0.06 μg/ml for the former and 0.14 μg/ml for the latter. PMID:407840

INACTIVATION OF SOME SEMISYNTHETIC PENICILLINS BY GRAM-NEGATIVE BACILLI

PubMed Central

Sabath, Leon; Finland, Maxwell

1963-01-01

Sabath, Leon (Boston City Hospital, Boston, Mass.) and Maxwell Finland. Inactivation of some semisynthetic penicillins by gram-negative bacilli. J. Bacteriol. 85:314–321. 1963.—An agar diffusion method was used to test 55 strains of gram-negative bacilli for their ability to inactivate penicillin G, methicillin, biphenylpenicillin, oxacillin, and ampicillin; 26 strains inactivated one or more of them. All strains of Klebsiella-Aerobacter, nearly all of Escherichia coli, and some of Pseudomonas aeruginosa, but not those of Proteus or Salmonella, were active by this method. Penicillin G was inactivated by the largest number of strains, biphenylpenicillin and ampicillin by somewhat fewer, and oxacillin and methicillin by about half as many. When the five penicillins were incubated with four strains of different bacteria in broth at 37 C, all were inactivated to a considerable extent by all the strains, each penicillin to a different degree, but to about the same extent by all the strains. Adsorption alone did not account for the loss of activity. The results suggest that there are qualitative, as well as quantitative, differences among species or even strains of gram-negative bacilli in their ability to inactivate the various penicillins. Images PMID:13975857

Gold nanostructure-integrated silica-on-silicon waveguide for the detection of antibiotics in milk and milk products

NASA Astrophysics Data System (ADS)

Ozhikandathil, Jayan; Badilescu, Simona; Packirisamy, Muthukumaran

2012-10-01

Antibiotics are extensively used in veterinary medicine for the treatment of infectious diseases. The use of antibiotics for the treatment of animals used for food production raised the concern of the public and a rapid screening method became necessary. A novel approach of detection of antibiotics in milk is reported in this work by using an immunoassay format and the Localized Surface Plasmon Resonance property of gold. An antibiotic from the penicillin family that is, ampicillin is used for testing. Gold nanostructures deposited on a glass substrate by a novel convective assembly method were heat-treated to form a nanoisland morphology. The Au nanostructures were functionalized and the corresponding antibody was absorbed from a solution. Solutions with known concentrations of antigen (antibiotics) were subsequently added and the spectral changes were monitored step by step. The Au LSPR band corresponding to the nano-island structure was found to be suitable for the detection of the antibody antigen interaction. The detection of the ampicillin was successfully demonstrated with the gold nano-islands deposited on glass substrate. This process was subsequently adapted for the integration of gold nanostructures on the silica-on-silicon waveguide for the purpose of detecting antibiotics.

Clustering of antibiotic resistance of E. coli in couples: suggestion for a major role of conjugal transmission.

PubMed

Lietzau, Susanne; Raum, Elke; von Baum, Heike; Marre, Reinhard; Brenner, Hermann

2006-07-18

Spread of antibiotic resistance in hospitals is a well-known problem, but studies investigating the importance of factors potentially related to the spread of resistant bacteria in outpatients are sparse. Stool samples were obtained from 206 healthy couples in a community setting in Southern Germany in 2002-2003. E. coli was cultured and minimal inhibition concentrations were tested. Prevalences of E. coli resistance to commonly prescribed antibiotics according to potential risk factors were ascertained. Prevalences of ampicillin resistance were 15.7% and 19.4% for women and men, respectively. About ten percent and 15% of all isolates were resistant to cotrimoxazole and doxycycline, respectively. A partner carrying resistance was the main risk factor for being colonized with resistant E. coli. Odds ratios (95% CI) for ampicillin and cotrimoxazole resistance given carriage of resistant isolates by the partner were 6.9 (3.1-15.5) and 3.3 (1.5-18.0), respectively. Our data suggest that conjugal transmission may be more important for the spread of antibiotic resistance in the community setting than commonly suspected risk factors such as previous antibiotic intake or hospital contacts.

A gold immunochromatographic assay for the rapid and simultaneous detection of fifteen β-lactams

NASA Astrophysics Data System (ADS)

Chen, Yanni; Wang, Yongwei; Liu, Liqiang; Wu, Xiaoling; Xu, Liguang; Kuang, Hua; Li, Aike; Xu, Chuanlai

2015-10-01

A novel gold immunochromatographic assay (GICA) based on anti-β-lactam receptors was innovatively developed that successfully allowed rapid and simultaneous detection of fifteen β-lactams in milk samples in 5-10 minutes. By replacing the antibodies used in traditional GICA with anti-β-lactam receptors, the difficulty in producing broad specific antibodies against β-lactams was overcome. Conjugates of ampicillin with BSA and goat anti-mouse immunoglobulin (IgG) were immobilized onto the test and control lines on the nitrocellulose membrane, respectively. Since goat anti-mouse IgG does not combine with receptors, negative serum from mice labelled with gold nanoparticles (GNP) was mixed with GNP-labelled receptors. Results were obtained within 20 min using a paper-based sensor. The utility of the assay was confirmed by the analysis of milk samples. The limits of detection (LOD) for amoxicillin, ampicillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, nafcillin, oxacillin, cefaclor, ceftezole, cefotaxime, ceftiofur, cefoperazone, cefathiamidine, and cefepime were 0.25, 0.5, 0.5, 0.5, 1, 5, 5, 10, 25, 10, 100, 10, 5, 5, and 2 ng mL-1, respectively, which satisfies the maximum residue limits (MRL) set by the European Union (EU). In conclusion, our newly developed GICA-based anti-β-lactam receptor assay provides a rapid and effective method for one-site detection of multiple β-lactams in milk samples.A novel gold immunochromatographic assay (GICA) based on anti-β-lactam receptors was innovatively developed that successfully allowed rapid and simultaneous detection of fifteen β-lactams in milk samples in 5-10 minutes. By replacing the antibodies used in traditional GICA with anti-β-lactam receptors, the difficulty in producing broad specific antibodies against β-lactams was overcome. Conjugates of ampicillin with BSA and goat anti-mouse immunoglobulin (IgG) were immobilized onto the test and control lines on the nitrocellulose membrane, respectively. Since goat anti-mouse IgG does not combine with receptors, negative serum from mice labelled with gold nanoparticles (GNP) was mixed with GNP-labelled receptors. Results were obtained within 20 min using a paper-based sensor. The utility of the assay was confirmed by the analysis of milk samples. The limits of detection (LOD) for amoxicillin, ampicillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, nafcillin, oxacillin, cefaclor, ceftezole, cefotaxime, ceftiofur, cefoperazone, cefathiamidine, and cefepime were 0.25, 0.5, 0.5, 0.5, 1, 5, 5, 10, 25, 10, 100, 10, 5, 5, and 2 ng mL-1, respectively, which satisfies the maximum residue limits (MRL) set by the European Union (EU). In conclusion, our newly developed GICA-based anti-β-lactam receptor assay provides a rapid and effective method for one-site detection of multiple β-lactams in milk samples. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04987c

[Bacteremia associated with mycotic aneurysm of the transversal aortic arch and myocarditis caused by Salmonella enteritidis].

PubMed

Martínez-Martínez, L; Mesa, E; Rodríguez, J E; Sánchez, M P; Ugarte, J; Algora Weber, A; Dámaso, D; Daza, R M; Mendaza, P

1989-02-01

A 60-year-old male with diabetes mellitus had Salmonella enteritidis bacteremia associated with mycotic aneurysm of the transverse aortic arc and myocarditis. Antibiotic therapy with ampicillin and chloramphenicol was ineffective despite the fact that the microorganism was sensitive in vitro to those antimicrobials, and the patient had a progressive clinical deterioration which culminated in death.

Antimicrobial Resistance Among Uropathogens That Cause Childhood Community-acquired Urinary Tract Infections in Central Israel.

PubMed

Yakubov, Renata; van den Akker, Machiel; Machamad, Kaba; Hochberg, Amit; Nadir, Erez; Klein, Adi

2017-01-01

In this retrospective study 829 positive urine cultures were analyzed. Escherichia coli bacterium was the leading uropathogen (86%). Almost 60% were resistant to ampicillin and first generation cephalosporins, and about 30% of them resistant to amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole. Almost none of them were resistant to second and third generation cephalosporins, aminoglycosides, ciprofloxacin or nitrofurantoin.

76 FR 17336 - New Animal Drugs; Amikacin Sulfate, Ampicillin Trihydrate, Ceftiofur Hydrochloride, Cephapirin...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

... treat cattle for more than 7 days. Milk from treated cows must not be used for food during treatment or... milk or milk replacer. 0 3. In Sec. 520.905a, revise paragraphs (e)(2)(i), (e)(2)(iii), (e)(3)(i), and... sulfadimethoxine. (iii) Limitations. Do not administer within 7 days of slaughter; milk that has been taken from...

Susceptibility of Escherichia coli isolated from uteri of postpartum dairy cows to antibiotic and environmental bacteriophages. Part II: In vitro antimicrobial activity evaluation of a bacteriophage cocktail and several antibiotics.

PubMed

Santos, T M A; Gilbert, R O; Caixeta, L S; Machado, V S; Teixeira, L M; Bicalho, R C

2010-01-01

The use of pathogenic-specific antimicrobials, as proposed by bacteriophage therapy, is expected to reduce the incidence of resistance development. Eighty Escherichia coli isolated from uteri of Holstein dairy cows were phenotypically characterized for antimicrobial resistance to ampicillin, ceftiofur, chloramphenicol, florfenicol, spectinomycin, streptomycin, and tetracycline by broth microdilution method. The lytic activity of a bacteriophage cocktail against all isolates was performed by a similar method. Additionally, the effect of different concentrations of antimicrobials and multiplicities of infections (MOI) of the bacteriophage cocktail on E. coli growth curve was measured. Isolates exhibited resistance to ampicillin (33.7%), ceftiofur (1.2%), chloramphenicol (100%), and florfenicol (100%). All strains were resistant to at least 2 of the antimicrobial agents tested; multidrug resistance (>or=3 of 7 antimicrobials tested) was observed in 35% of E. coli isolates. The major multidrug resistance profile was found for ampicillin-chloramphenicol-florfenicol, which was observed in more than 96.4% of the multidrug-resistant isolates. The bacteriophage cocktail preparation showed strong antimicrobial activity against multidrug-resistant E. coli. Multiplicity of infection as low as 10(-4) affected the growth of the E. coli isolates. The ratio of 10 bacteriophage particles per bacterial cell (MOI=10(1)) was efficient in inhibiting at least 50% of all isolates. Higher MOI should be tested in future in vitro studies to establish ratios that completely inhibit bacterial growth during longer periods. All isolates resistant to florfenicol were resistant to chloramphenicol and, because florfenicol was recently introduced into veterinary clinics, this finding suggests that the selection pressure of chloramphenicol, as well as other antimicrobials, may still play a relevant role in the emergence and dissemination of florfenicol resistance in E. coli. The bacteriophage cocktail had a notable capacity to inhibit the in vitro growth of E. coli isolates, and it may be an attractive alternative to conventional treatment of metritis by reducing E. coli in uteri of postpartum dairy cows. Copyright 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Short communication: Pharmacokinetics of intramammary hetacillin in dairy cattle milked 3 times per day.

PubMed

Lindquist, Danielle A; Baynes, Ronald E; Smith, Geof W

2015-03-01

Mastitis remains a critical disease in the dairy industry and the use of intramammary antibiotics plays a critical role in mastitis treatment. Hetacillin is currently approved as an intramammary antibiotic that is used to treat mastitis in dairy cows. It is approved for once a day administration and can be used for a total of 3 d. An increasing number of dairy farms are milking 3 times per day (instead of the traditional 2 times per day) and very little pharmacokinetic data exists on the use of intramammary drugs in a 3×system. The primary purpose of this study was to determine if once a day intramammary infusion of hetacillin is sufficient to maintain therapeutic drug concentrations in cattle milked 3 times per day. Eight Holstein cattle milked 3 times per day were used in this study. After collecting a baseline milk sample, each cow received intramammary infusions of hetacillin in the left front and right rear quarters once a day for 3 d. Milk samples from each of the treated quarters were collected at each milking and frozen until analysis. Milk samples were analyzed for ampicillin concentrations using an ultra-performance liquid chromatography method. All treated quarters had antibiotic concentrations well above the minimum inhibitory concentration (MIC) for gram-positive mastitis pathogens at 8 and 16 h postinfusion. Milk concentrations had fallen well below the MIC by the 24-h period (before the next infusion). All 8 cows in this study consistently had individual quarter milk ampicillin concentrations below the FDA tolerance of 0.01 μg/mL (10 ppb) within 48 h of the last infusion. Based on this study, milk ampicillin concentrations exceed the minimum inhibitory concentration required to inhibit the growth of 90% of organisms (MIC90) for at least 65% of the dosing interval, which is sufficient for once-daily dosing with most cases of gram-positive mastitis. Therefore, intramammary hetacillin should be an effective treatment for the vast majority of gram-positive mastitis pathogens when used according to label (once per day) in cows milked 3 times per day. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Comprehensive Evaluation of the MBT STAR-BL Module for Simultaneous Bacterial Identification and β-Lactamase-Mediated Resistance Detection in Gram-Negative Rods from Cultured Isolates and Positive Blood Cultures.

PubMed

Lee, Annie W T; Lam, Johnson K S; Lam, Ricky K W; Ng, Wan H; Lee, Ella N L; Lee, Vicky T Y; Sze, Po P; Rajwani, Rahim; Fung, Kitty S C; To, Wing K; Lee, Rodney A; Tsang, Dominic N C; Siu, Gilman K H

2018-01-01

Objective: This study evaluated the capability of a MALDI Biotyper system equipped with the newly introduced MBT STAR-BL module to simultaneously perform species identification and β-lactamase-mediated resistance detection in bacteremia -causing bacteria isolated from cultured isolates and patient-derived blood cultures (BCs). Methods: Two hundred retrospective cultured isolates and 153 prospective BCs containing Gram-negative rods (GNR) were collected and subjected to direct bacterial identification, followed by the measurement of β-lactamase activities against ampicillin, piperacillin, cefotaxime, ceftazidime, and meropenem using the MBT STAR-BL module. The results and turnaround times were compared with those of routine microbiological processing. All strains were also characterized by beta-lactamase PCR and sequencing. Results: Using the saponin-based extraction method, MALDI-TOF MS correctly identified bacteria in 116/134 (86.6%) monomicrobial BCs. The detection sensitivities for β-lactamase activities against ampicillin, piperacillin, third-generation cephalosporin and meropenem were 91.3, 100, 97.9, and 100% for cultured isolates, and 80.4, 100, 68.8, and 40% for monomicrobial BCs ( n = 134) respectively. The overall specificities ranged from 91.5 to 100%. Furthermore, the MBT STAR-BL and conventional drug susceptibility test results were concordant in 14/19 (73.7%) polymicrobial cultures. Reducing the logRQ cut-off value from 0.4 to 0.2 increased the direct detection sensitivities for β-lactamase activities against ampicillin, cefotaxime and meropenem in BCs to 85.7, 87.5, and 100% respectively. The MBT STAR-BL test enabled the reporting of β-lactamase-producing GNR at 14.16 and 47.64 h before the interim and final reports of routine BCs processing, respectively, were available. Conclusion: The MALDI Biotyper system equipped with the MBT STAR-BL module enables the simultaneous rapid identification of bacterial species and β-lactamase-mediated resistance from BCs and cultured isolates. Adjustment of the logRQ cut-off value to 0.2 significantly increased the detection sensitivities for clinically important drug-resistant pathogens.

Haemophilus influenzae type-b and non-b-type invasive diseases in urban children (<5years) of Bangladesh: implications for therapy and vaccination.

PubMed

Rahman, Mahbubur; Hossain, Shahadat; Baqui, Abdullah Hel; Shoma, Shereen; Rashid, Harunur; Nahar, Nazmun; Zaman, Mohammed Khalequ; Khatun, Farida

2008-03-01

To prospectively study the epidemiology and antibiotic resistance of Haemophilus infuenzae isolates from invasive infections in children. Children (<5years) with pneumonia, meningitis and septicemia from three hospitals in Dhaka, Bangladesh were enrolled (1999-2003); clinical and laboratory data, and blood for cultures were collected. Cerebrospinal fluid (CSF) of meningitis cases was analyzed (Gram stain, culture and biochemical tests). Hib antigen was detected by latex agglutination (LA) in culture-negative pyogenic CSF and PCR was done for bexA gene in culture- and LA-negative pyogenic CSF. Antibiotic susceptibility was determined by E-Tests and beta-lactamase by nitrocefin stick. Seventy-three cases of H. influenzae infections (46 of 293 meningitis cases, 25 of 1493 pneumonia cases, 2 of 48 septicemia cases) were detected; 63%, 34% and 3% of them had meningitis, pneumonia and septicemia respectively. H. influenzae type b (Hib) caused infections in 80.8% of cases (60.3% meningitis, 20.5% pneumonia). Most (86%) infections clustered in 4-12month infants. The case-fatality in pneumonia was 8% compared to 19% in meningitis. H. influenzae isolates from pneumonia and meningitis children were equally resistant to antibiotics (46% vs 43%). Of 10 drugs tested, isolates were resistant to ampicillin (31%), chloramphenicol (42%), trimethoprim-sulfamethoxazole (44%) and azithromycin (1.4%). Multidrug-resistant (MDR) strains were equally prevalent in Hib (31%) and non-b-type (29%) isolates, and in pneumonia (31%) and meningitis (34%) cases. None was resistant to amoxicillin-clavulanate, ceftriaxone, ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin. Of all H. influenzae infections, 40%, 4.4% and 100% of pneumonia, meningitis and septicemia cases were caused by other serotypes or non-typeable strains. All ampicillin-resistant-strains produced beta-lactamase without detection of beta-lactamase-negative-ampicillin-resistant (BLNAR) strains. Hib is a leading cause of invasive bacterial infections in infants. Multidrug-resistant H. influenzae is common and requires amoxicillin-clavulanate, ceftriaxone or azithromycin as empirical therapy with specific recommendation for use of ceftriaxone for treatment of meningitis particularly MDR cases. New fluoroquinolines has potential utility. An effective national Hib vaccination programme is essential in Bangladesh although non-Hib infections will remain an issue.

Effect of recombinant human gamma interferon on intracellular activities of antibiotics against Listeria monocytogenes in the human macrophage cell line THP-1.

PubMed Central

Scorneaux, B; Ouadrhiri, Y; Anzalone, G; Tulkens, P M

1996-01-01

Listeria monocytogenes is a facultative intracellular pathogen which enters cells by endocytosis and reaches phagolysosomes from where it escapes and multiplies in the cytosol of untreated cells. Exposure of macrophages to gamma interferon (IFN-gamma) restricts L. monocytogenes to phagosomes and prevents its intracellular multiplication. We have tested whether IFN-gamma also modulates the susceptibility of L. monocytogenes to antibiotics. We selected drugs from three different classes displaying marked properties concerning their cellular accumulation and subcellular distribution, namely, ampicillin (not accumulated by cells but present in cytosol), azithromycin (largely accumulated by cells but mostly restricted to lysosomes), and sparfloxacin (accumulated to a fair extent but detected only in cytosol). We used a continuous line of myelomonocytic cells (THP-1 macrophages), which display specific surface receptors for IFN-gamma, and examined the activity of these antibiotics against L. monocytogenes Hly+ (virulent variant) and L. monocytogenes Hly- (a nonvirulent variant defective in hemolysin production). Untreated THP-1 and phorbol myristate acetate-differentiated THP-1 were permissive for infection and multiplication of intracellular L. monocytogenes Hly+ (virulent variant). All three antibiotics tested were bactericidal against this Listeria strain when added to an extracellular concentration of 10x their MIC. After preexposure of THP-1 to IFN-gamma, L. monocytogenes Hly+ was still phagocytosed but no longer grew intracellularly. The activity of ampicillin became almost undetectable (antagonistic effect), and that of azithromycin was unchanged (additive effect with that of IFN-gamma), whereas that of sparfloxacin was markedly enhanced (synergy). A similar behavior (lack of bacterial growth, associated with a loss of activity of ampicillin, an enhanced activity of sparfloxacin, and unchanged activity of azithromycin) was observed in cells infected with L. monocytogenes Hly-. This modulation of antibiotic activity, which we ascribe to the change of subcellular localization of L. monocytogenes caused by IFN-gamma or by the lack of virulence factor, could result from a change in bacterial responsiveness to antibiotics, a modification of the drug activity, or differences in drug bioavailabilities between cytosol and phagosomes. PMID:8723471

Modeling solubility, acid-base properties and activity coefficients of amoxicillin, ampicillin and (+)6-aminopenicillanic acid, in NaCl(aq) at different ionic strengths and temperatures.

PubMed

Crea, Francesco; Cucinotta, Daniela; De Stefano, Concetta; Milea, Demetrio; Sammartano, Silvio; Vianelli, Giuseppina

2012-11-20

The total solubility of three penicillin derivatives was determined, in pure water and NaCl aqueous solutions at different salt concentrations (from ∼0.15 to 1.0 mol L(-1) for ampicillin and amoxicillin, and from ∼0.05 to 2.0 mol L(-1) for (+)6-aminopenicillanic acid), using the shake-flask method for generating the saturated solutions, followed by potentiometric analysis. The knowledge of the pH of solubilization and of the protonation constants determined in the same experimental conditions, allowed us to calculate, by means of the mass balance equations, the solubility of the neutral species at different ionic strength values, to model its dependence on the salt concentration and to determine the corresponding values at infinite dilution. The salting parameter and the activity coefficients of the neutral species were calculated by the Setschenow equation. The protonation constants of ampicillin and amoxicillin, determined at different temperatures (from T=288.15 to 318.15K), from potentiometric and spectrophotometric measurements, were used to calculate, by means of the Van't Hoff equation, the temperature coefficients at different ionic strength values and the corresponding protonation entropies. The protonation enthalpies of the (+)6-aminopenicillanic acid were determined by isoperibol calorimetric titrations at T=298.15K and up to I=2.0 mol L(-1). The dependence of the protonation constants on ionic strength was modeled by means of the Debye-Hückel and SIT (Specific ion Interaction Theory) approaches, and the specific interaction parameters of the ionic species were determined. The hydrolysis of the β-lactam ring was studied by spectrophotometric and H NMR investigations as a function of pH, ionic strength and time. Potentiometric measurements carried out on the hydrolyzed (+)6-aminopenicillanic acid allowed us to highlight that the opened and the closed β-lactam forms of the (+)6-aminopenicillanic acid have quite different acid-base properties. An analysis of literature solubility, protonation constants, enthalpies and activity coefficients is reported too. Copyright © 2012 Elsevier B.V. All rights reserved.

Comprehensive Evaluation of the MBT STAR-BL Module for Simultaneous Bacterial Identification and β-Lactamase-Mediated Resistance Detection in Gram-Negative Rods from Cultured Isolates and Positive Blood Cultures

PubMed Central

Lee, Annie W. T.; Lam, Johnson K. S.; Lam, Ricky K. W.; Ng, Wan H.; Lee, Ella N. L.; Lee, Vicky T. Y.; Sze, Po P.; Rajwani, Rahim; Fung, Kitty S. C.; To, Wing K.; Lee, Rodney A.; Tsang, Dominic N. C.; Siu, Gilman K. H.

2018-01-01

Objective: This study evaluated the capability of a MALDI Biotyper system equipped with the newly introduced MBT STAR-BL module to simultaneously perform species identification and β-lactamase-mediated resistance detection in bacteremia -causing bacteria isolated from cultured isolates and patient-derived blood cultures (BCs). Methods: Two hundred retrospective cultured isolates and 153 prospective BCs containing Gram-negative rods (GNR) were collected and subjected to direct bacterial identification, followed by the measurement of β-lactamase activities against ampicillin, piperacillin, cefotaxime, ceftazidime, and meropenem using the MBT STAR-BL module. The results and turnaround times were compared with those of routine microbiological processing. All strains were also characterized by beta-lactamase PCR and sequencing. Results: Using the saponin-based extraction method, MALDI-TOF MS correctly identified bacteria in 116/134 (86.6%) monomicrobial BCs. The detection sensitivities for β-lactamase activities against ampicillin, piperacillin, third-generation cephalosporin and meropenem were 91.3, 100, 97.9, and 100% for cultured isolates, and 80.4, 100, 68.8, and 40% for monomicrobial BCs (n = 134) respectively. The overall specificities ranged from 91.5 to 100%. Furthermore, the MBT STAR-BL and conventional drug susceptibility test results were concordant in 14/19 (73.7%) polymicrobial cultures. Reducing the logRQ cut-off value from 0.4 to 0.2 increased the direct detection sensitivities for β-lactamase activities against ampicillin, cefotaxime and meropenem in BCs to 85.7, 87.5, and 100% respectively. The MBT STAR-BL test enabled the reporting of β-lactamase-producing GNR at 14.16 and 47.64 h before the interim and final reports of routine BCs processing, respectively, were available. Conclusion: The MALDI Biotyper system equipped with the MBT STAR-BL module enables the simultaneous rapid identification of bacterial species and β-lactamase-mediated resistance from BCs and cultured isolates. Adjustment of the logRQ cut-off value to 0.2 significantly increased the detection sensitivities for clinically important drug-resistant pathogens. PMID:29527202

The effect of urea and ammonia treatments on the survival of Salmonella spp. and Yersinia enterocolitica in pig slurry.

PubMed

Bolton, D J; Ivory, C; McDowell, D A

2013-01-01

The objective of this study was to investigate the survival of Salmonella and Yersinia enterocolitica strains in pig slurry and evaluate urea and ammonia as disinfection strategies. Salmonella Anatum, Salmonella Derby, Salmonella Typhimurium DT19 and Y. enterocolitica bioserotypes 4, O:3, 2, O:5,27 and 1A, O:6,30 were selectively marked by insertion of the plasmid, pGLO encoding for green fluorescent protein and for ampicillin resistance. Strain cocktails were inoculated into fresh pig slurry (control), slurry treated with urea [final concentration 2% w/w, (0.33 mol l(-1) )] and slurry treated with ammonia [final concentration 0.5% w/w, (0.3 mol l(-1) )] and stored at 4, 14 and 25°C. Bacterial counts were determined at regular intervals on xylose lysine deoxycholate agar (XLD), and XLD supplemented with ampicillin (0.1 mg ml(-1) ) and arabinose (0.6 mg ml(-1) ) for Salmonella and cefsulodin-irgasan-novobiocin agar (CIN) and CIN supplemented with ampicillin and arabinose for Y. enterocolitica. The pH of the control-, urea- and ammonia-treated samples ranged from 7.1 to 7.7, 8.8 to 8.9 and 8.0 to 8.3, respectively. Salmonella D(4) values ranged from 2.71 to 21.29 days, D(14) values from 2.72 to 11.62 days and D(25) values from 1.76 to 6.85 days. The equivalent D values ranges for the Y. enterocolitica strains were 3.7-19.23, 1.8-16.67 and 1.63-7.09 days, respectively. Treatment significantly (P < 0.01) affected D values with control > ammonia > urea, as did incubation temperature; 4 > 14 > 25°C. Urea and to a lesser extent ammonia may be used to disinfect Salmonella- and/or Y. enterocolitica-contaminated pig slurry, decreasing the storage time required while increasing its fertilizer value. This study presents data supporting the treatment of pig slurry to kill important zoonotic agents, thereby reducing environmental contamination, cross-infection of other animals and decreasing zoonotic disease in the food chain. © 2012 The Society for Applied Microbiology.

Cefepime shows good efficacy and no antibiotic resistance in pneumonia caused by Serratia marcescens and Proteus mirabilis - an observational study.

PubMed

Yayan, Josef; Ghebremedhin, Beniam; Rasche, Kurt

2016-03-23

Many antibiotics have no effect on Gram-positive and Gram-negative microbes, which necessitates the prescription of broad-spectrum antimicrobial agents that can lead to increased risk of antibiotic resistance. These pathogens constitute a further threat because they are also resistant to numerous beta-lactam antibiotics, as well as other antibiotic groups. This study retrospectively investigates antimicrobial resistance in hospitalized patients suffering from pneumonia triggered by Gram-negative Serratia marcescens or Proteus mirabilis. The demographic and clinical data analyzed in this study were obtained from the clinical databank of the HELIOS Clinic, Witten/Herdecke University, Wuppertal, Germany, for inpatients presenting with pneumonia triggered by S. marcescens or P. mirabilis from 2004 to 2014. An antibiogram was conducted for the antibiotics utilized as part of the management of patients with pneumonia triggered by these two pathogens. Pneumonia was caused by Gram-negative bacteria in 115 patients during the study period from January 1, 2004, to August 12, 2014. Of these, 43 (37.4 %) hospitalized patients [26 males (60.5 %, 95 % CI 45.9 %-75.1 %) and 17 females (39.5 %, 95 % CI 24.9 %-54.1 %)] with mean age of 66.2 ± 13.4 years had pneumonia triggered by S. marcescens, while 20 (17.4 %) patients [14 males (70 %, 95 % CI 49.9 %-90.1 %) and 6 females (30 %, 95 % CI 9.9 %-50.1 %)] with a mean age of 64.6 ± 12.8 years had pneumonia caused by P. mirabilis. S. marcescens showed an increased antibiotic resistance to ampicillin (100 %), ampicillin-sulbactam (100 %), and cefuroxime (100 %). P. mirabilis had a high resistance to tetracycline (100 %) and ampicillin (55 %). S. marcescens (P < 0.0001) and P. mirabilis (P = 0.0003) demonstrated no resistance to cefepime in these patients with pneumonia. S. marcescens and P. mirabilis were resistant to several commonly used antimicrobial agents, but showed no resistance to cefepime.

[Considerations on the antibiotic activity (M.I.C.) revealed in 247 serotypes of Salmonella].

PubMed

Pitzus, E; Peretti, P; Ghinelli, P; Bisicchia, R; Turano, A

1975-01-01

247 strains of Salmonella, isolated in Brescia province duriing 1973-1974 have been typed by serological methods. The MIC has been determined, using the following antibiotics: chloramphenicol, tetracycline HCL, ampicillin, doxycycline, rifampicin, cephazolin, carbenicillin, nifuratel, gentamicin, aminosidine, trimetho-prim-sulphamethoazole, nalidixic acid. The pattern of resistence of the various serotypes is quite constant. The relationship between diffusion and epidermiological factors are discussed.

Antimicrobial Susceptibility Survey of Streptococcus pyogenes Isolated in Japan from Patients with Severe Invasive Group A Streptococcal Infections

PubMed Central

Ikebe, Tadayoshi; Hirasawa, Kyoko; Suzuki, Rieko; Isobe, Junko; Tanaka, Daisuke; Katsukawa, Chihiro; Kawahara, Ryuji; Tomita, Masaaki; Ogata, Kikuyo; Endoh, Miyoko; Okuno, Rumi; Watanabe, Haruo

2005-01-01

We assessed antimicrobial susceptibility against 211 Streptococcus pyogenes strains isolated from patients with severe invasive group A streptococcal infections. Overall, 3.8, 1.4, 1.4, and 0.5% of the isolates were resistant to erythromycin, clindamycin, telithromycin, and ciprofloxacin, respectively, and 10.4% had intermediate resistance to ciprofloxacin. All isolates were susceptible to ampicillin and cefotaxime. PMID:15673769

Reconsidering the Current Preterm Premature Rupture of Membranes Antibiotic Prophylactic Protocol.

PubMed

Wolf, Maya Frank; Miron, Dan; Peleg, David; Rechnitzer, Hagai; Portnov, Igor; Salim, Raed; Keness, Yoram; Reich, Dan; Ami, Moshe Ben; Peretz, Avi; Koshnir, Amir; Shachar, Inbar Ben

2015-11-01

The purpose of our study was to determine whether the current antibiotic regimen for preterm premature rupture of membranes (PPROM) is adequate for covering the current causative agents and sensitivities of chorioamnionitis and early-onset neonatal sepsis. During a 3-year period, we retrieved the results from placental and amniotic membrane cultures obtained at delivery in cases of maternal fever, chorioamnionitis, and PPROM, and from blood cultures obtained from neonates with early-onset sepsis (EOS) in three participating hospitals. Sensitivity of pathogens to antimicrobial agents was performed using routine microbiologic techniques. There were 1,133 positive placental or amniotic cultures, 740 (65.3%) were from gram-negative Enterobacteriaceae. There were 27 neonates diagnosed with EOS with positive blood cultures. Aerobic Enterobacteriaceae accounted for 14 cases (52%) and group B streptococcus for 7 cases (26%). Of the Escherichia coli and Klebsiella sp., only 38% were sensitive to ampicillin. Local pathogens and their antibiotic sensitivity profiles should be explored every few years and an effective antibiotic protocol chosen to cover the main pathogens causing chorioamnionitis and EOS. Consideration should be made for changing ampicillin in women with PPROM to a regimen with better coverage of gram-negative Enterobacteriaceae. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Antibacterial properties of parasitic mistletoe - Scurrula ferruginea (Jack) Danser of Brunei Darussalam

NASA Astrophysics Data System (ADS)

David, Sheba R.; Amni Adam, Amira; Rajabalaya, Rajan

2017-12-01

Natural products especially from plants have become subject of much interest in drug discovery. Scurrula ferruginea is parasitic mistletoe used traditionally to treat various illnesses. The aim of this study is to investigate the potential antibacterial effect of Scurrula ferruginea native to Brunei Darussalam. The plants were collected from Brunei-Muara district air-dried, pulverized into powder, extracted by water maceration and freeze dried. Later, the extract was screened by disc-diffusion assay for two bacterial strains. The positive controls were Gentamycin and Ampicillin for Staphylococcus aureus while Sulphamethoxazole was used for Escherichia coli. Dimethyl sulfoxide was the negative control for both strains. 100, 200 and 500 mg/ml of the extract were used for the assays. The extracts did not show any inhibition activity against Escherichia coli, while sulphamethoxazole, showed inhibition of 24 mm. Ampicillin, Gentamycin, 100 and 500 mg/ml extract exhibited 29, 20, 8.3 and 10.7 mm inhibition zone, respectively against Staphylococcus aureus. There was an increase in zone of inhibition on Staphylococcus aureus strain with increase in extract concentration. Further investigations including Minimum Inhibition Concentration and Minimum Bactericidal Concentration methods as well as investigation on additional bacterial strains will be conducted for confirmation of antibacterial effect of the extract.

Antimicrobial resistance 1979-2009 at Karolinska hospital, Sweden: normalized resistance interpretation during a 30-year follow-up on Staphylococcus aureus and Escherichia coli resistance development.

PubMed

Kronvall, Göran

2010-09-01

To utilize a material of inhibition zone diameter measurements from disc diffusion susceptibility tests between 1979 and 2009, an objective setting of epidemiological breakpoints was necessary because of methodological changes. Normalized resistance interpretation (NRI) met this need and was applied to zone diameter histograms for Staphylococcus aureus and Escherichia coli isolates. The results confirmed a slow resistance development as seen in Northern countries. The S. aureus resistance levels for erythromycin, clindamycin and fusidic acid in 2009 were 3.2%, 1.8% and 1.4% with denominator correction. A rise in resistance to four antimicrobials in 1983 was probably because of a spread of resistant Methicillin Susceptible Staphylococcus Aureus (MSSA). For E. coli, the denominator-corrected resistance levels in 2009 were 27% for ampicillin, around 3% for third-generation cephalosporins, 0.1% for imipenem, 2.5% for gentamicin, 19% for trimethoprim, 4.5% for co-trimoxazole, 1.2% for nitrofurantoin and 9% for ciprofloxacin. The temporal trends showed a rise in fluoroquinolone resistance from 1993, a parallel increase in gentamicin resistance, a substantial increase in trimethoprim and sulphonamide resistance in spite of decreased consumption, and a steady rise in ampicillin resistance from a constant level before 1989. A short review of global resistance surveillance studies is included.

Antibiotic Resistance of Bacteria Involved in Urinary Infections in Brazil: A Cross-Sectional and Retrospective Study

PubMed Central

Rodrigues, Wellington Francisco; Miguel, Camila Botelho; Nogueira, Ana Paula Oliveira; Ueira-Vieira, Carlos; Paulino, Tony De Paiva; Soares, Siomar De Castro; De Resende, Elisabete Aparecida Mantovani Rodrigues; Lazo-Chica, Javier Emilio; Araújo, Marcelo Costa; Oliveira, Carlo José

2016-01-01

Empirical and prolonged antimicrobial treatment of urinary tract infections caused by Escherichia coli is associated with the emergence of bacterial resistance, and not all countries have strict policies against the indiscriminate use of drugs in order to prevent resistance. This cross-sectional and retrospective study (2010–2015) aimed to evaluate the sensitivity and resistance of patient-derived E. coli to different drugs broadly used to treat urinary infections in Brazil: ampicillin + sulbactam, cephalothin, ciprofloxacin, norfloxacin, and nitrofurantoin. We obtained 1654 E. coli samples from ambulatory patients with disease symptoms of the urinary tract from a Brazilian public hospital. While all antibiotics were effective in killing E. coli to a large degree, nitrofurantoin was the most effective, with fewer samples exhibiting antibiotic resistance. We assessed the costs of generic and brand name versions of each antibiotic. Nitrofurantoin, the most effective antibiotic, was the cheapest, followed by the fluoroquinolones (ciprofloxacin and norfloxacin), ampicillin + sulbactam and, lastly, cephalothin. Finally, assessment of antibiotic resistance to fluoroquinolones over the study period and extrapolation of the data led to the conclusion that these antibiotics could no longer be effective against E. coli-based urinary infections in approximately 20 years if their indiscriminate use in empirical treatment continues. PMID:27649224

Antibiotic-resistant bacteria in the Hudson River Estuary linked to wet weather sewage contamination.

PubMed

Young, Suzanne; Juhl, Andrew; O'Mullan, Gregory D

2013-06-01

Heterotrophic bacteria resistant to tetracycline and ampicillin were assessed in waterways of the New York City metropolitan area using culture-dependent approaches and 16S rRNA gene sequence analysis of resultant isolates. Resistant microbes were detected at all 10 sampling sites in monthly research cruises on the lower Hudson River Estuary (HRE), with highest concentrations detected at nearshore sites. Higher frequency sampling was conducted in Flushing Bay, to enumerate resistant microbes under both dry and wet weather conditions. Concentrations of ampicillin- and tetracycline-resistant bacteria, in paired samples, were positively correlated with one another and increased following precipitation. Counts of the fecal indicator, Enterococcus, were positively correlated with levels of resistant bacteria, suggesting a shared sewage-associated source. Analysis of 16S rRNA from isolates identified a phylogenetically diverse group of resistant bacteria, including genera containing opportunistic pathogens. The occurrence of Enterobacteriaceae, a family of enteric bacteria, was found to be significantly higher in resistant isolates compared to total heterotrophic bacteria and increased following precipitation. This study is the first to document the widespread distribution of antibiotic-resistant bacteria in the HRE and to demonstrate clearly a link between the abundance of antibiotic-resistant bacteria and levels of sewage-associated bacteria in an estuary.

Salmonella, including antibiotic-resistant Salmonella, from flies captured from cattle farms in Georgia, U.S.A.

PubMed

Xu, Yumin; Tao, Sha; Hinkle, Nancy; Harrison, Mark; Chen, Jinru

2018-03-01

Flies can be transmission vehicles of Salmonella from cattle to humans. This study determined the prevalence of Salmonella in/on flies captured from 33 cattle farms, including 5 beef and 28 dairy farms, in Georgia, USA, and characterized antibiotic resistance profiles of the isolated Salmonella. Twenty-six out of the 33 cattle farms (79%) and 185 out of the 1650 flies (11%) tested positive for Salmonella in the study. The incidence of Salmonella-positive flies varied from farm to farm, ranging from 0 to 78%. Among the 185 Salmonella isolated from flies, 29% were resistant to ampicillin, 28% to tetracycline, 21% to amoxicillin/clavulanic acid, 20% to cefoxitin, and 12% to streptomycin. Incidences of resistance against other tested antibiotics were low, ranging from 0 to 3%. Furthermore, 28% of the Salmonella isolates were multidrug resistant, demonstrating resistance to 3 or more antibiotics. The minimal inhibitory concentrations of ampicillin, cefoxitin, streptomycin, and tetracycline against the Salmonella isolates ranged from 32 to >2048, 64 to 2048, 128 to 1024, and 32 to 1024μg/mL, respectively. These data suggest that flies could be effective vehicles of transmitting antibiotic resistant Salmonella and disseminating antibiotic resistance genes on cattle farms, posing risks to human and animal health. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalence and Antimicrobial Resistance of Salmonella Isolated from Animal-Origin Food Items in Gondar, Ethiopia

PubMed Central

Garedew, Legesse; Alebachew, Zabishwork; Worku, Walelgn

2016-01-01

Salmonella has been found to be the major cause of foodborne diseases and a serious public health problem in the world, with an increasing concern for the emergence and spread of antimicrobial-resistant strains. A cross-sectional study was conducted between February 2014 and December 2015 on food items of animal origin to assess the prevalence and antimicrobial resistance profiles of Salmonella isolates using standard bacteriological methods. The overall prevalence rate of 5.5% was recorded from the total analyzed food items of animal origin. Salmonella isolates were detected from 12% of raw meat, 8% of minced meat, 2.9% of burger samples, 18% of raw eggs, and 6% of raw milk. Furthermore, antimicrobial susceptibility test identified 47.6% resistant Salmonella isolates, 28.6% intermediately sensitive isolates, and 23.8% susceptible isolates. Among Salmonella isolates tested, 42.6%, 28.6%, and 14.3% were found to be relatively resistant to tetracycline, sulfamethoxazole-trimethoprim, and ampicillin, respectively, while 9.5%–19% were intermediately resistant to tetracycline, amoxicillin, ampicillin, cephalothin, and nitrofurantoin. Therefore, our findings provide the prevalence and drug resistance of Salmonella from foods of animal origin and contribute information to scientists as well as public health researchers to minimize the prevalent and resistant foodborne Salmonella species in Ethiopia. PMID:28074185

Early-Onset Neonatal Sepsis

PubMed Central

Simonsen, Kari A.; Anderson-Berry, Ann L.; Delair, Shirley F.

2014-01-01

SUMMARY Early-onset sepsis remains a common and serious problem for neonates, especially preterm infants. Group B streptococcus (GBS) is the most common etiologic agent, while Escherichia coli is the most common cause of mortality. Current efforts toward maternal intrapartum antimicrobial prophylaxis have significantly reduced the rates of GBS disease but have been associated with increased rates of Gram-negative infections, especially among very-low-birth-weight infants. The diagnosis of neonatal sepsis is based on a combination of clinical presentation; the use of nonspecific markers, including C-reactive protein and procalcitonin (where available); blood cultures; and the use of molecular methods, including PCR. Cytokines, including interleukin 6 (IL-6), interleukin 8 (IL-8), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α), and cell surface antigens, including soluble intercellular adhesion molecule (sICAM) and CD64, are also being increasingly examined for use as nonspecific screening measures for neonatal sepsis. Viruses, in particular enteroviruses, parechoviruses, and herpes simplex virus (HSV), should be considered in the differential diagnosis. Empirical treatment should be based on local patterns of antimicrobial resistance but typically consists of the use of ampicillin and gentamicin, or ampicillin and cefotaxime if meningitis is suspected, until the etiologic agent has been identified. Current research is focused primarily on development of vaccines against GBS. PMID:24396135

Antibiotic Resistance of Salmonella spp. Isolated from Shrimp Farming Freshwater Environment in Northeast Region of Brazil

PubMed Central

Carvalho, Fátima C. T.; Sousa, Oscarina V.; Carvalho, Edirsana M. R.; Hofer, Ernesto; Vieira, Regine H. S. F.

2013-01-01

This study investigated the presence and antibiotic resistance of Salmonella spp. in a shrimp farming environment in Northeast Region of Brazil. Samples of water and sediments from two farms rearing freshwater-acclimated Litopenaeus vannamei were examined for the presence of Salmonella. Afterwards, Salmonella isolates were serotyped, the antimicrobial resistance was determined by a disk diffusion method, and the plasmid curing was performed for resistant isolates. A total of 30 (16.12%) of the 186 isolates were confirmed to be Salmonella spp., belonging to five serovars: S. serovar Saintpaul, S. serovar Infantis, S. serovar Panama, S. serovar Madelia, and S. serovar Braenderup, along with 2 subspecies: S. enterica serovar houtenae and S. enterica serovar enterica. About twenty-three percent of the isolates were resistant to at least one antibiotic, and twenty percent were resistant to at least two antibiotics. Three strains isolated from water samples (pond and inlet canal) exhibited multiresistance to ampicillin, tetracycline, oxytetracycline, and nitrofurantoin. One of them had a plasmid with genes conferring resistance to nitrofurantoin and ampicillin. The incidence of bacteria pathogenic to humans in a shrimp farming environment, as well as their drug-resistance pattern revealed in this study, emphasizes the need for a more rigorous attention to this area. PMID:24455280

Fecal contamination of drinking water in Kericho District, Western Kenya: role of source and household water handling and hygiene practices.

PubMed

Too, Johana Kiplagat; Kipkemboi Sang, Willy; Ng'ang'a, Zipporah; Ngayo, Musa Otieno

2016-08-01

Inadequate protection of water sources, and poor household hygienic and handling practices have exacerbated fecal water contamination in Kenya. This study evaluated the rate and correlates of thermotolerant coliform (TTC) household water contamination in Kericho District, Western Kenya. Culture and multiplex polymerase chain reaction (PCR) techniques were used to characterize TTCs. The disk diffusion method was used for antibiotic susceptibility profiling of pathogenic Escherichia coli. Out of the 103 households surveyed, 48 (46.6%) had TTC contaminated drinking water (TTC levels of >10 cfu/100 mL). Five of these households were contaminated with pathogenic E. coli, including 40% enteroaggregative E. coli, 40% enterotoxigenic E. coli, and 20% enteropathogenic E. coli. All these pathogenic E. coli strains were multidrug resistant to sulfamethoxazole/trimethoprim, ampicillin, tetracycline and ampicillin/sulbactam. Rural household locality, drinking water hand contact, water storage container cleaning practice, hand washing before water withdrawal, water source total coliforms <10 cfu/100 mL, temperature, and free chlorine levels were associated with TTC contamination of household drinking water. Significant proportions of household drinking water in Kericho District are contaminated with TTCs including with pathogenic multidrug-resistant E. coli. Source and household hygiene and practices contribute significantly to drinking water contamination.

Antimicrobial Resistance Patterns in Women with Positive Urine Culture: Does Menopausal Status Make a Significant Difference?

PubMed

Miotla, Pawel; Romanek-Piva, Katarzyna; Bogusiewicz, Michal; Markut-Miotla, Ewa; Adamiak, Aneta; Wróbel, Andrzej; Zebrowska, Małgorzata; Wawrysiuk, Sara; Mendyk, Katarzyna; Rechberger, Ewa; Jakubczak, Agata; Rechberger, Tomasz

2017-01-01

Aim . Urinary tract infection (UTI) is considered one of the most common bacterial infections in women. The aim of this study was to investigate the types of uropathogens present, as well as the degree of antimicrobial drug resistance seen among premenopausal ( n = 2748) and postmenopausal ( n = 1705) women with uncomplicated UTI. Methods . Urinary samples ( n = 4453) collected from women with UTI were analyzed in terms of uropathogens present. These were considered as positive if bacterial growth was ≥10 5 colony forming units (CFUs)/mL. Susceptibility and resistance testing for commonly used antibiotics was subsequently assessed. Results . The most common uropathogens cultured from urine samples were Escherichia coli (65.5%), followed by Enterococcus faecalis (12.2%), Klebsiella pneumoniae (4.7%), and Proteus mirabilis (4.2%). The resistance to ampicillin exceeded 40%, independently of menopausal status. Of note, resistance to ciprofloxacin exceeded 25% among postmenopausal patients. Moreover, resistance of all uropathogens to commonly used antimicrobials was significantly higher in postmenopausal women. Conclusion . Due to the high resistance rate, ampicillin, ciprofloxacin, and the trimethoprim/sulfamethoxazole combination should be avoided in treating postmenopausal women affected by UTI without being indicated by initial urine culture report. Finally, cephalexin and cefuroxime are promising alternatives as initial treatment in postmenopausal women.

Screening for Salmonella in backyard chickens.

PubMed

Manning, Johanna; Gole, Vaibhav; Chousalkar, Kapil

2015-06-15

Salmonellosis is a significant zoonotic disease which has a considerable economic impact on the egg layer industry. There is limited information about the prevalence of Salmonella spp. in backyard chickens. The current study was conducted to determine the prevalence of Salmonella in backyard chickens, and the associated virulence of any serovars identified. Hundred and fifteen pooled samples from 30 backyard flocks in South Australia were screened. Four flocks tested positive for Salmonella spp. The overall Salmonella isolation rate in the current study was 10.4%. The estimated prevalence at individual bird level was 0.02% (95% CI 0.025-0.975). The serovars isolated were Salmonella Agona, Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) and Salmonella Bovismorbificans. All Salmonella isolates tested positive for the prgH, orfL and spiC genes. The Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) had the most antibiotic resistance, being resistant to ampicillin and cephalothin and having intermediate resistance to florphenicol. All of the Salmonella Agona had intermediate resistance to the ampicillin, while the Salmonella Bovismorbificans were susceptible to all antibiotics tested. With the increased interest of keeping backyard chickens, the current study highlights the zoonotic risk from Salmonella spp. associated with home flocks. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Changing Epidemiology of Serious Bacterial Infections in Febrile Infants without Localizing Signs

PubMed Central

Watt, Kevin; Waddle, Erica; Jhaveri, Ravi

2010-01-01

Objective Historically, management of infants with fever without localizing signs (FWLS) has generated much controversy, with attempts to risk stratify based on several criteria. Advances in medical practice may have altered the epidemiology of serious bacterial infections (SBIs) in this population. We conducted this study to test the hypothesis that the rate of SBIs in this patient population has changed over time. Patients and Methods We performed a retrospective review of all infants meeting FWLS criteria at our institution from 1997–2006. We examined all clinical and outcome data and performed statistical analysis of SBI rates and ampicillin resistance rates. Results 668 infants met criteria for FWLS. The overall rate of SBIs was 10.8%, with a significant increase from 2002–2006 (52/361, 14.4%) compared to 1997–2001 (20/307, 6.5%) (p = 0.001). This increase was driven by an increase in E. coli urinary tract infections (UTI), particularly in older infants (31–90 days). Conclusions We observed a significant increase in E. coli UTI among FWLS infants with high rates of ampicillin resistance. The reasons are likely to be multifactorial, but the results themselves emphasize the need to examine urine in all febrile infants <90days and consider local resistance patterns when choosing empiric antibiotics. PMID:20805983

In vitro sensitivity of Hungarian Actinobaculum suis strains to selected antimicrobials.

PubMed

Biksi, I; Major, Andrea; Fodor, L; Szenci, O; Vetési, F

2003-01-01

In vitro antimicrobial sensitivity of 12 Hungarian isolates and the type strain ATCC 33144 of Actinobaculum suis to different antimicrobial compounds was determined both by the agar dilution and by the disc diffusion method. By agar dilution, MIC50 values in the range of 0.05-3.125 micrograms/ml were determined for penicillin, ampicillin, ceftiofur, doxycycline, tylosin, pleuromutilins, chloramphenicol, florfenicol, enrofloxacin and lincomycin. The MIC50 value of oxytetracycline and spectinomycin was 6.25 and 12.5 micrograms/ml, respectively. For ofloxacin, flumequine, neomycin, streptomycin, gentamicin, nalidixic acid, nitrofurantoin and sulphamethoxazole + trimethoprim MIC50 values were in the range of 25-100 micrograms/ml. With the disc diffusion method, all strains were sensitive to penicillin, cephalosporins examined, chloramphenicol and florfenicol, tetracyclines examined, pleuromutilins, lincomycin and tylosin. Variable sensitivity was observed for fluoroquinolones (flumequine, enrofloxacin, ofloxacin), most of the strains were susceptible to marbofloxacin. Almost all strains were resistant to aminoglycosides but most of them were sensitive to spectinomycin. A strong correlation was determined for disc diffusion and MIC results (Spearman's rho 0.789, p < 0001). MIC values of the type strain and MIC50 values of other tested strains did not differ significantly. Few strains showed a partially distinct resistance pattern for erythromycin, lincomycin and ampicillin in both methods.

Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP.

PubMed

Czulak, J; Guerreiro, A; Metran, K; Canfarotta, F; Goddard, A; Cowan, R H; Trochimczuk, A W; Piletsky, S

2016-06-07

Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates.

Efficacy of trimethoprim/sulfamethoxazole in experimental Escherichia coli bacteremia and meningitis.

PubMed

Kim, K S; Anthony, B F

1983-01-01

We evaluated the activity of trimethoprim/sulfamethoxazole (TMP/SMZ) against a K1 Escherichia coli strain. Minimal inhibitory and bactericidal concentrations were 0.06/1.14 and 0.25/4.75 micrograms/ml, respectively. In vivo studies using an infant rat model of bacteremia and meningitis revealed that TMP/SMZ penetrated well into the cerebrospinal fluid (CSF) and that 37% of serum levels were achieved. The efficacy of TMP/SMZ was compared with that of ampicillin, chloramphenicol, cefotaxime and lamoxactam. Bacterial clearance from blood and CSF was significantly greater with TMP/SMZ than with ampicillin or chloramphenicol and mortality was significantly less than with chloramphenicol (p less than 0.01). However, 3 of 21 (14%) and 2 of 8 animals (25%) still had positive blood and CSF cultures after 3 days of treatment with TMP/SMZ. None of the survivors in the cefotaxime and lamoxactam groups were bacteremic after 1 day of therapy. Furthermore, 5 of 13 animals (38%) treated with TMP/SMZ developed meningitis during therapy, in contrast with none in the cefotaxime and lamoxactam groups. These findings indicate that although the activity of TMP/SMZ is bactericidal in vitro and in vivo against E. coli, TMP/SMZ may not provide optimal therapy for gram-negative bacillary meningitis in this model.

Regulation by commensal bacteria of neurogenesis in the subventricular zone of adult mouse brain.

PubMed

Sawada, Naoki; Kotani, Takenori; Konno, Tasuku; Setiawan, Jajar; Nishigaito, Yuka; Saito, Yasuyuki; Murata, Yoji; Nibu, Ken-Ichi; Matozaki, Takashi

2018-04-15

In the mouse olfactory bulb (OB), interneurons such as granule cells and periglomerular cells are continuously replaced by adult-born neurons, which are generated in the subventricular zone (SVZ) of the brain. We have now investigated the role of commensal bacteria in regulation of such neuronal cell turnover in the adult mouse brain. Administration of mixture of antibiotics to specific pathogen-free (SPF) mice markedly attenuated the incorporation of bromodeoxyuridine (BrdU) into the SVZ cells. The treatment with antibiotics also reduced newly generated BrdU-positive neurons in the mouse OB. In addition, the incorporation of BrdU into the SVZ cells of germ-free (GF) mice was markedly reduced compared to that apparent for SPF mice. In contrast, the reduced incorporation of BrdU into the SVZ cells of GF mice was recovered by their co-housing with SPF mice, suggesting that commensal bacteria promote the incorporation of BrdU into the SVZ cells. Finally, we found that administration of ampicillin markedly attenuated the incorporation of BrdU into the SVZ cells of SPF mice. Our results thus suggest that ampicillin-sensitive commensal bacteria regulate the neurogenesis in the SVZ of adult mouse brain. Copyright © 2018 Elsevier Inc. All rights reserved.

Antibiotic resistance and biofilm formation of some bacteria isolated from sediment, water and fish farms in Malaysia

NASA Astrophysics Data System (ADS)

Faja, Orooba Meteab; Usup, Gires; Ahmad, Asmat

2018-04-01

A total of 90 isolates of bacteria were isolated, from sediment (10) samples, water (10) samples and fish (12) samples (Sea bass, Snapper, Grouper and Tilapia). These include 22 isolates of bacteria from sediment, 28 isolates from water and 40 isolates from fish. All the isolates were tested for sensitivity to 13 antibiotics using disc diffusion method. The isolates showed high resistance to some antibiotics based on samples source. Isolates from sediment showed highest resistance toward novobiocin, kanamycin, ampicillin and streptomycin while isolates from water showed highest resistance against vancomycin, penicillin, streptomycin and tetracycline, in contrast, in fish sample showed highest resistance toward vancomycin, ampicillin, streptomycin and tetracycline. Most of the isolates showed biofilm formation ability with different degrees. Out of 22 bacteria isolates from water, two isolates were weak biofilm formers, six isolates moderate biofilm formers and fourteen isolates strong biofilm formers. While, out of 28 bacteria isolates from water one isolate was weak biofilm former, five isolates moderate biofilm formers and 22 strong biofilm formers Fish isolate showed three isolates (8%) moderate biofilm formers and 27 isolates strong biofilm formers. Biofilm formation was one of the factors that lead to antibiotic resistance of the bacterial isolates from these samples.

Demographic features and antibiotic resistance among children hospitalized for urinary tract infection in northwest Iran.

PubMed

Ghorashi, Ziaaedin; Ghorashi, Sona; Soltani-Ahari, Hassan; Nezami, Nariman

2011-01-01

Urinary tract infection (UTI) is the most common serious bacterial infection during infancy. The aim of the present study was to evaluate demographic characteristics, clinical presentations and findings, and antimicrobial resistance among infants and children hospitalized in Tabriz Children's Hospital, Tabriz, Iran. In this descriptive observational study, 100 children who had been admitted with UTI diagnosis to Tabriz Children's Hospital from March 2003 to March 2008 were studied. Demographic characteristics, chief complaints, clinical presentations and findings, urine analysis and cultures, antimicrobial resistance, and sonographic and voiding cystourethrographic reports were evaluated. The mean age of patients was 35.77 ± 39.86 months. The male to female ratio was 0.26. The mean white blood cell count was 12,900 ± 5226/mm(3). Sixty-two percent of patients had leukocytosis. The most common isolated pathogen was Escherichia coli spp (77%) followed by Klebsiella spp (10%), Enterobacter spp (9%), and Enterococcus spp (4%). Isolated pathogens were highly resistant to ampicillin, cotrimoxazole, and cephalexin (71%-96%), intermediate sensitivity to third-generation cephalosporins, and highly sensitive to ciprofloxacin (84.4%), amikacin (83.8%), and nitrofurantoin (82.8%). The most common pathogen of UTI in the hospitalized children was E. coli spp. The isolated pathogens were extremely resistant to ampicillin, and highly sensitive to ciprofloxacin and amikacin.

Antibiotics for community-acquired pneumonia in children.

PubMed

Lodha, Rakesh; Kabra, Sushil K; Pandey, Ravindra M

2013-06-04

Pneumonia caused by bacterial pathogens is the leading cause of mortality in children in low-income countries. Early administration of antibiotics improves outcomes. To identify effective antibiotic drug therapies for community-acquired pneumonia (CAP) of varying severity in children by comparing various antibiotics. We searched CENTRAL 2012, Issue 10; MEDLINE (1966 to October week 4, 2012); EMBASE (1990 to November 2012); CINAHL (2009 to November 2012); Web of Science (2009 to November 2012) and LILACS (2009 to November 2012). Randomised controlled trials (RCTs) in children of either sex, comparing at least two antibiotics for CAP within hospital or ambulatory (outpatient) settings. Two review authors independently extracted data from the full articles of selected studies. We included 29 trials, which enrolled 14,188 children, comparing multiple antibiotics. None compared antibiotics with placebo.Assessment of quality of study revealed that 5 out of 29 studies were double-blind and allocation concealment was adequate. Another 12 studies were unblinded but had adequate allocation concealment, classifying them as good quality studies. There was more than one study comparing co-trimoxazole with amoxycillin, oral amoxycillin with injectable penicillin/ampicillin and chloramphenicol with ampicillin/penicillin and studies were of good quality, suggesting the evidence for these comparisons was of high quality compared to other comparisons.In ambulatory settings, for treatment of World Health Organization (WHO) defined non-severe CAP, amoxycillin compared with co-trimoxazole had similar failure rates (odds ratio (OR) 1.18, 95% confidence interval (CI) 0.91 to 1.51) and cure rates (OR 1.03, 95% CI 0.56 to 1.89). Three studies involved 3952 children.In children with severe pneumonia without hypoxaemia, oral antibiotics (amoxycillin/co-trimoxazole) compared with injectable penicillin had similar failure rates (OR 0.84, 95% CI 0.56 to 1.24), hospitalisation rates (OR 1.13, 95% CI 0.38 to 3.34) and relapse rates (OR 1.28, 95% CI 0.34 to 4.82). Six studies involved 4331 children below 18 years of age.In very severe CAP, death rates were higher in children receiving chloramphenicol compared to those receiving penicillin/ampicillin plus gentamicin (OR 1.25, 95% CI 0.76 to 2.07). One study involved 1116 children. For treatment of patients with CAP in ambulatory settings, amoxycillin is an alternative to co-trimoxazole. With limited data on other antibiotics, co-amoxyclavulanic acid and cefpodoxime may be alternative second-line drugs. Children with severe pneumonia without hypoxaemia can be treated with oral amoxycillin in an ambulatory setting. For children hospitalised with severe and very severe CAP, penicillin/ampicillin plus gentamycin is superior to chloramphenicol. The other alternative drugs for such patients are co-amoxyclavulanic acid and cefuroxime. Until more studies are available, these can be used as second-line therapies.There is a need for more studies with radiographically confirmed pneumonia in larger patient populations and similar methodologies to compare newer antibiotics. Recommendations in this review are applicable to countries with high case fatalities due to pneumonia in children without underlying morbidities and where point of care tests for identification of aetiological agents for pneumonia are not available.

Vaginitis. Reducing the number of refractory cases.

PubMed

Josey, W E

1977-09-01

Therapeutic failure in vaginitis can be minimized if all cases are properly diagnosed and specific therapy is given. Use of wet mounts combined with liberal use of cultures, especially for Corynebacterium vaginale, should result in an accurate diagnosis in over 90% of cases. Treatment of choice for candidiasis is nystatin or miconazole nitrate applied topically. For trichomoniasis, metronidazole should be given orally to both sexual partners. Ampicillin, cephalexin, or cephradine are recommended for C vaginale infection.

[Dynamics of the population structure of the Escherichia coli recombinant strain during continuous culture].

PubMed

Popova, L Iu; Lutskaia, N I; Bogucharov, A A; Bril'kov, A V; Pechurkin, N S

1992-01-01

The populational structure of the Escherichia coli strain Z905 containing the recombinant plasmid with the phenotype AprLux+ was studied in chemostat. It was shown that the stability of the ratio of plasmid containing cells and cells without plasmids depends in the first place on the presence of the selective factor (ampicillin) in the medium and on the sources of carbon and energy limiting growth.

Antibacterial resistances in uncomplicated urinary tract infections in women: ECO·SENS II data from primary health care in Austria

PubMed Central

2012-01-01

Background Uncomplicated urinary tract infections (UTI) are a frequent reason for consultation of women in primary health care. To avoid therapy failure and development of resistances, the choice of an antibiotic should be based on the knowledge of recent local resistance data but these data are scarce for the Austrian primary health care sector. Within the context of the ECO·SENS II study it was the aim to obtain appropriate and relevant local resistance data and describe the changes in the resistance pattern in comparison to the ECO·SENS study. Methods 23 GPs from different parts of Austria participated in the study between July 2007 and November 2008. According to the defined inclusion- and exclusion criteria female patients with symptoms of an uncomplicated UTI were included and a midstream urine sample was collected. In case of significant bacteriuria susceptibility testing of E. coli against 14 antibiotics was performed. Descriptive statistical methods were used. Results In 313 patients included in the study, a total of 147 E. coli isolates (47%) were detected and tested. The resistance rates were in %: Mecillinam (0.0), nitrofurantoin (0.7), fosfomycin trometamol (0.7), gentamycin (1.4), cefotaxime (2.7), ceftazidime (2.7), Cephadroxil (4.1) and ciprofloxacin (4.1). Higher resistance rates were found in amoxicillin/clavulanic acid (8.9), nalidixic acid (9.6), trimethoprim/sulphamethoxazole (14.4), trimethoprim (15.8), sulphamethoxazole (21.2) and ampicillin (28.8). Additionally, the comparison of these results with the results of the ECO·SENS study demonstrated an increase in resistance rates of ampicillin, amoxicillin/clavulanic acid, nalidixic acid and ciprofloxacin. Conclusions The resistance data for E. coli in uncomplicated UTIs in women gained by this study are the most recent data for this disease in Austria at the moment. The increased resistance rates of amoxicillin/clavulanic acid, ciprofloxacin and nalidixic acid should be respected when choosing an appropriate antibiotic for uncomplicated UTIs. The use of ampicillin, sulphamethoxazole, trimethoprim and trimethoprim/sulphametoxazole in uncomplicated UTIs in women should be questioned at all. The findings of this study should result in a regular surveillance system of resistances emerging in the ambulatory sector designed after the model of the EARS-Net. PMID:22989349

Management of listeriosis.

PubMed Central

Hof, H; Nichterlein, T; Kretschmar, M

1997-01-01

Determination of the MIC in vitro is often used as the basis for predicting the clinical efficacy of antibiotics. Listeriae are uniformly susceptible in vitro to most common antibiotics except cephalosporins and fosfomycin. However, the clinical outcome is poor. This is partially because listeriae are refractory to the bactericidal mechanisms of many antibiotics, especially to ampicillin-amoxicillin, which still is regarded as the drug of choice. A true synergism can be achieved by adding gentamicin. Another point is that listeriae are able to reside and multiply within host cells, e.g., macrophages, hepatocytes, and neurons, where they are protected from antibiotics in the extracellular fluid. Only a few agents penetrate, accumulate, and reach the cytosol of host cells, where the listeriae are found. Furthermore, certain host cells may exclude antibiotics from any intracellular compartment. Thus, determination of the antibacterial efficacy of a drug against listeriae in cell cultures may be a better approximation of potential therapeutic value. Certain host cells may have acquired the property of excluding certain antibiotics, for example macrolides, from intracellular spaces, which might explain therapeutic failures of antibiotic therapy in spite of low MICs. Animal models do not completely imitate human listeriosis, which is characterized by meningitis, encephalitis, soft tissue and parenchymal infections, and bacteremia. Meningitis produced in rabbits is a hyperacute disease, whereby most listeriae lie extracellularly, fairly accessible to antibiotics that can cross the blood-cerebrospinal fluid barrier. In the murine model of systemic infection, Listeria monocytogenes is located mainly within macrophages and parenchymal cells of the spleen and liver, hardly accessible to certain drugs, such as ampicillin and gentimicin. The therapeutic efficacy of drugs clearly depends on the model used. Thus, for example, the combination of ampicillin with gentamicin acts synergistically in the rabbit meningitis model but not in the mouse model. Since conventional antimicrobial therapy with antibiotics is not satisfactory, particularly in the immunocompromised host (about 30% of patients with listeriosis die in spite of a rational choice of antibiotics), other possibilities must be considered for therapy as well as prevention. Indeed, listeriae are highly susceptible to several endogenous antibiotics, such as defensins. Bacteriocins produced by related bacterial species, e.g., lactobacilli and enterococci, are rapidly bactericidal. However, unfortunately, the use of such alternative measures along with immunization and immunmodulation is not yet feasible. PMID:9105758

Laboratory aspects of asymptomatic bacteriuria in pregnancy.

PubMed

Mohammad, Marlyn; Mahdy, Zaleha A; Omar, Jamil; Maan, Noorashikin; Jamil, M A

2002-09-01

A total of 1,661 pregnant women aged between 13 and 45 years were screened for bacteriuria by urine culture. Of the 1,661 culture results, 615 (37%) yielded no growth; 728 (43.8%) yielded no significant growth (presence of <10(5) organisms/ml urine of one or more types of bacteria); 286 (17.2%) yielded mixed growth (presence of >10(5) organisms/ml urine of more than one type of bacteria) and only 32 (1.9%) showed significant growth (presence of >10(5) organisms/ml urine of a single bacterium). Urine microscopy was also conducted. Two hundred and twenty-four (13.5%) specimens had >10 white blood cells/ml urine, of which 66 had >100 white blood cells; 13 were from the significant growth group. Three hundred and seventy-four (22.5%) specimens showed the presence of bacteria, 42 (2.5%) had red blood cells, 370 (22.3%) had epithelial cells, 58 (3.5%) had crystals, and 14 (0.8%) had yeasts. The most common bacterium isolated was Escherichia coli (12; 40%); the others included group B Streptococcus (5; 15%), Klebsiella spp (5; 15%), Diphtheroids (2), and Candida albicans (2). Fifty-two percent of tested strains were sensitive to ampicillin; 24 of 28 strains (85.7%) were sensitive to ciprofloxacin; all 7 strains tested were sensitive to nitrofurantoin and all 20 strains tested were sensitive to cotrimoxazole; 14/20 (70%) and 16/17 (94.1%) were sensitive to cephalexin and cefuroxime respectively. This study shows that asymptomatic bacteriuria does occur in pregnant women, albeit at a very low rate in an urban setting like Cheras. Urine microscopy is not specific and only serves as a guide to bacteriuria. The commonest causative organisms are those from the gastrointestinal tract and vagina. The antibiogram showed that cefuroxime and cephalexin are likely to be effective in treating bacteriuria: ampicillin must be reserved for Gram-negative organisms. For Gram-positive organisms, of which Group B Streptococcus is important, ampicillin is still effective in vitro. Nitrofurantion and cotrimoxazole have excellent activity in vitro and should be considered for therapy. 17.2% of the urine culture yielded mixed growth: likely to indicate that contamination of urine specimens still happens despite the strict instructions given to patients about the collection of a midstream urine specimen. Proper collection, appropriate transport, and the early processing of urine specimens remain essential.

Extrachromosomal DNA length and antibiograms of Staphylococcus aureus and Pseudomonas aeruginosa isolated from tears of HIV/AIDS patients after curing with sodium dodecyl sulphate.

PubMed

Ajayi, B O; Otajevwo, F D

2012-01-01

Staphylococcus aureus and Pseudomonas aeruginosa strains were isolated from eye swab samples randomly obtained from 100 seropositive HIV/AIDS patients who reported to various anti-retroviral treatment clinics at the University of Benin Teaching Hospital and Central Hospital both based in Benin City, Nigeria. Invitro antibiotic sensitivity patterns of strains before curing were determined by the Kirby-Bauer disc diffusion technique. Resistance plasmid DNA of multidrug resistant strains was cured with 0.1% sodium dodecyl sulphate and cured strains were again subjected to in vitro antibiotic sensitivity testing. EcoRI and Hind III restriction endonuclease enzymes were used to make cuts on extracted plasmid DNA whose length sizes were then determined. A total of 36 (36.0%) strains made up of 27 (75.0%) Staphylococcus. aureus and 9 (25.0%) Pseudomonas aeruginosa were isolated of which 7 (19.4%) strains showed multidrug resistance to ciprofloxacin, pefloxacin, ofloxacine, gentamycin, tetracycline, ampicillin, chloramphenicol, nitrofurantoin and erythromycin. All seven multidrug resistant strains before curing, recorded 85.7%, 42.9%, 14.3% and 14.3% sensitivity in that decreasing order to ciprofloxacin, pefloxacin, ofloxacin and gentamycin respectively. There was 0.0% sensitivity each to tetracycline and ampicillin. After curing, there was enhanced sensitivity of 100.0%, 85.7%, 28.6% and 71.4% respectively. There was also 28.6% and 57.1% improved sensitivity to tetracycline and ampicillin after curing. Before curing, there was 76.2% average resistance to all used antibiotics and this reduced to 47.6% after curing Staph. aureus plasmid DNA. In the case of Pseudomonas aeruginosa, there was an average resistance of 76.3% before curing which fell to 42.5% after curing. EcoRI restriction enzyme gave the plasmid DNA length of Staphylococcus aureus strain 04 as 4.0Kb and this size depended upon the distance between recognition sites. Isolation of 36 (36.0%) strains of both isolates from 100 eye swabs shows the danger these organisms portend to all categories of opticians. The cheapness and high sensitivity of gentamycin justifies its use as eye drops for treatment of some eye infections. Curing of plasmid DNA is an indication that if SDS is administered to the organisms in sublethal doses, it can lead to the elimination of plasmid DNA without adverse effect on the genomic DNA of the bacterial strains.

Purification and synergistic antibacterial activity of arginine derived cyclic dipeptides, from Achromobacter sp. associated with a rhabditid entomopathogenic nematode against major clinically relevant biofilm forming wound bacteria

PubMed Central

Deepa, Indira; Kumar, Sasidharan N.; Sreerag, Ravikumar S.; Nath, Vishnu S.; Mohandas, Chellapan

2015-01-01

Skin and chronic wound infections caused by various pathogenic bacteria are an increasing and urgent health problem worldwide. In the present investigation ethyl acetate extract of an Achromobacter sp. associated with a Rhabditis entomopathogenic nematode (EPN), displayed promising antibacterial property and was further purified by silica gel column chromatography to get three different cyclic dipeptides (CDPs). Based on the spectral data and Marfey's analyses, the CDPs were identified as cyclo(D-Leu-D-Arg) (1), cyclo(L-Trp-L-Arg) (2), and cyclo(D-Trp-D-Arg) (3), respectively. Three CDPs were active against all the 10 wound associated bacteria tested. The significant antibacterial activity was recorded by CDP 3, and highest activity of 0.5 μg/ml was recorded against Staphylococcus aureus and Pseudomonas aeruginosa. The synergistic antibacterial activities of CDPs and ampicillin were assessed using the checkerboard microdilution method. The results of the current study recorded that the combined effects of CDPs and ampicillin principally recorded synergistic activity. Interestingly, the combination of CDPs and ampicillin also recorded enhanced inhibition of biofilm formation by bacteria. Moreover, CDPs significantly stimulate the production of IL-10 and IL-4 (anti-inflammatory cytokines) by human peripheral blood mononuclear cells. CDPs do not make any significant effect on the production of pro-inflammatory cytokines like TNF-α. The three CDPs have been studied for their effect on intracellular S. aureus in murine macrophages (J774) using 24 h exposure to 0.5X, 1X, and 2X MIC concentrations. Significant decrease in intracellular S. aureus burden was recorded by CDPs. CDPs also recorded no cytotoxicity toward FS normal fibroblast, VERO, and L231 normal lung epithelial cell lines. Antimicrobial activity of the arginine containing CDPs against the wound associated bacteria is reported here for the first. Moreover, this is also the first report on the production of CDPs by Achromobacter sp. Finally, we conclude that the Achromobacter sp. is an incredibly promising source of natural bioactive secondary metabolites especially against wound pathogenic bacteria that may receive significant benefit in the field of human medicine in near future as topical agents. PMID:26379651

Extrachromosomal DNA Length and Antibiograms of Staphylococcus aureus and Pseudomonas aeruginosa Isolated from Tears of HIV/AIDS Patients after Curing with Sodium Dodecyl Sulphate

PubMed Central

B. O., Ajayi; F. D., Otajevwo

2012-01-01

Staphylococcus aureus and Pseudomonas aeruginosa strains were isolated from eye swab samples randomly obtained from 100 seropositive HIV/AIDS patients who reported to various anti-retroviral treatment clinics at the University of Benin Teaching Hospital and Central Hospital both based in Benin City, Nigeria. Invitro antibiotic sensitivity patterns of strains before curing were determined by the Kirby-Bauer disc diffusion technique. Resistance plasmid DNA of multidrug resistant strains was cured with 0.1% sodium dodecyl sulphate and cured strains were again subjected to invitro antibiotic sensitivity testing. EcoRI and Hind III restriction endonuclease enzymes were used to make cuts on extracted plasmid DNA whose length sizes were then determined. A total of 36 (36.0%) strains made up of 27 (75.0%) Staphylococcus. aureus and 9 (25.0%) Pseudomonas aeruginosa were isolated of which 7 (19.4%) strains showed multidrug resistance to ciprofloxacin, pefloxacin, ofloxacine, gentamycin, tetracycline, ampicillin, chloramphenicol, nitrofurantoin and erythromycin. All seven multidrug resistant strains before curing, recorded 85.7%, 42.9%, 14.3% and 14.3% sensitivity in that decreasing order to ciprofloxacin, pefloxacin, ofloxacin and gentamycin respectively. There was 0.0% sensitivity each to tetracycline and ampicillin. After curing, there was enhanced sensitivity of 100.0%, 85.7%, 28.6% and 71.4% respectively. There was also 28.6% and 57.1% improved sensitivity to tetracycline and ampicillin after curing. Before curing, there was 76.2% average resistance to all used antibiotics and this reduced to 47.6% after curing Staph. aureus plasmid DNA. In the case of Pseudomonas aeruginosa, there was an average resistance of 76.3% before curing which fell to 42.5% after curing. EcoRI restriction enzyme gave the plasmid DNA length of Staphylococcus aureus strain 04 as 4.0Kb and this size depended upon the distance between recognition sites. Isolation of 36 (36.0%) strains of both isolates from 100 eye swabs shows the danger these organisms portend to all categories of opticians. The cheapness and high sensitivity of gentamycin justifies its use as eye drops for treatment of some eye infections. Curing of plasmid DNA is an indication that if SDS is administered to the organisms in sublethal doses, it can lead to the elimination of plasmid DNA without adverse effect on the genomic DNA of the bacterial strains. PMID:22980121

[Susceptibility to antimicrobial agents of 2,060 strains of different bacteria isolated in infectious processes in children].

PubMed

Filloy, L; Borjas, E; Sierra, A

1981-01-01

Susceptibility to antibiotics of 2060 strains of the following bacteria was studied: Escherichia coli, Klebsiella pneumoniae, Salmonella, Shigella, Proteus, Staphylococcus aureus that were isolated in 1978-79 from different infections in children hospitalized at the Hospital Infantil de Mexico. The antimicrobials submitted to the test of susceptibility were: ampicillin, amikacin, carbenicillin, cephalothin, cefoxitin, chloramphenicol, gentamicin, kanamycin, neomycin and sulfamethoxazole-trimethoprim. Present results are compared with previous studies.

[Achromobacter xylosoxidans bacteremia in a patient with community-acquired pneumonia].

PubMed

de Fernández, M I; Bugarín, G; Arévalo, C E

2001-01-01

Achromobacter xylosoxidans is a rare cause of bacteremia, and little information on treatment is available. The majority of patients who have developed Achromobacter bacteremia have presented predisposing causes to the infection. A case of community-acquired pneumonia and bacteremia due to A. xylosoxidans in a previously healthy patient is reported. Achromobacter is usually resistant to ampicillin, cephalosporins (1st, 2nd, and 3rd generation), aminoglycosides, and fluoroquinolones. Piperacillin, piperacillin-tazobactam, and trimethoprim-sulfamethoxazole inhibit most isolates.

Work Plan for Determining the Occurrence of Glyphosate, Its Transformation Product AMPA, Other Herbicide Compounds, and Antibiotics in Midwestern United States Streams, 2002

DTIC Science & Technology

2003-01-01

LCAA 0.05 µg/L propachlor OXA LCAA 0.05 µg/L Antibiotics Beta lactams amoxicillin LCAN 0.20 µg/L ampicillin LCAN 0.10 µg/L cefotaxime LCAN 0.10 µg/L... tylosin LCAN 0.10 µg/L virginiamycin LCAN 0.10 µg/L Quinolines ciprofloxacin LCAN 0.05 µg/L clinafloxacin LCAN 0.05 µg/L flumequine LCAN 0.05 µg/L

Effect of cooking and cold storage on biologically active antibiotic residues in meat.

PubMed Central

O'Brien, J. J.; Campbell, N.; Conaghan, T.

1981-01-01

An investigation was undertaken to see if cooking or cold storage would destroy or decrease the level of biologically active antibiotic in tissues from animals given therapeutic doses of antibiotic on three occasions prior to slaughter. The effects of cooking and cold storage on the biological activity of the residues of ampicillin, chloramphenicol, oxytetracycline, streptomycin and sulphadimidine were varied; in some instances the effects were minimal, in others nil. PMID:7310129

Chemical Communications

DTIC Science & Technology

2012-04-27

TOTAL: Patents Submitted Submitted: "Systems and Methods for Amplification and Phage Display", Derda, R., Tang, S.K.Y., Whitesides, G.M. PCT/US11...College 60 Oxford Street Cambridge MA 02138 5a: 5f-1a: 5f-c: Systems and Methods for Amplification and Phage Display Patent Filed in US? (5d-1) Y NPatent...the bacteriophage- T7 promoter (See S.I. for details). This series of FP encoding vectors contain the ampicillin-resistant gene as a selective marker

beta-Lactam resistance of motile Aeromonas isolates from clinical and environmental sources.

PubMed Central

Morita, K; Watanabe, N; Kurata, S; Kanamori, M

1994-01-01

The MICs of various beta-lactams for 182 isolates of Aeromonas species, i.e., A. hydrophila (n = 101), A. sobria (n = 69), and A. caviae (n = 12), from clinical and environmental sources were determined by an agar dilution technique. All strains were resistant to ampicillin and susceptible to aztreonam. A. sobria and A. caviae demonstrated lower resistance rates than A. hydrophila. Penicillin-hydrolyzing beta-lactamases were detected in all strains. PMID:8192463

Simultaneous delivery of antibiotics neomycin and ampicillin in drinking water inhibits fermentation of resistant starch in rats.

PubMed

Carvajal-Aldaz, Diana G; Guice, Justin L; Page, Ryan C; Raggio, Anne M; Martin, Roy J; Husseneder, Claudia; Durham, Holiday A; Geaghan, James; Janes, Marlene; Gauthier, Ted; Coulon, Diana; Keenan, Michael J

2017-03-01

Antibiotics ampicillin 1 g/L and neomycin 0.5 g/L were added to drinking water before or during feeding of resistant starch (RS) to rats to inhibit fermentation. In a preliminary study, antibiotics and no RS were given prior to rats receiving a transplant of cecal contents via gavage from donor rats fed RS (without antibiotics) or a water gavage before feeding resistant starch to both groups. Antibiotics given prior to feeding RS did not prevent later fermentation of RS regardless of either type of gavage. In the second study, antibiotics were given simultaneously with feeding of RS. This resulted in inhibition of fermentation of RS with cecal contents pH >8 and low amounts of acetate and butyrate. Rats treated with antibiotics had reduced Bifidobacteria spp., but similar Bacteroides spp. to control groups to reduce acetate and butyrate and preserve the production of propionate. Despite reduced fermentation, rats given antibiotics had increased glucagon-like peptide 1 (GLP-1) and cecum size, measures that are usually associated with fermentation. A simultaneous delivery of antibiotics inhibited fermentation of RS. However, increased GLP-1 and cecum size would be confounding effects in assessing the mechanism for beneficial effects of dietary RS by knocking out fermentation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performance evaluation of reverse osmosis technology for selected antibiotics removal from synthetic pharmaceutical wastewater

PubMed Central

2012-01-01

This study addresses the possibility for low pressure reverse osmosis membrane (RE 2521, CSM) process to serve as an alternative to remove selected antibiotics (ampicillin and amoxicillin) from synthetic wastewater by changing operating conditions such as pH = 3, 6.5 and 10; Pressure = 9, 11 and13 (bar); antibiotic concentration = 10, 255 and 500(mg/L), and temperature = 20, 30 and 40°C. The experiment was designed based on Box-benken, which is a Response Surface methodology design (RSM), using Design Expert software. The concentration of antibiotics was measured by applying a UV-spectrophotometer (Cecil), at the wavelength of 254 nm. Results showed a range of rejection percentage from 73.52% to 99.36% and 75.1% to 98.8%, for amoxicillin and ampicillin, respectively. Considering the solute rejections and the membrane porosity show that the prevailing rejection mechanism of the examined antibiotics by the membrane was the size exclusion effect. The permeate flux for both of the antibiotics was 12–18.73 L/m2.h. Although the permeate flux and antibiotic rejection are influenced by operating pressure, pH, and temperature individually, the interaction between operating parameters did not have noticeable effects. According to the results obtained in this study, the application of RO membrane is recommended for the selected antibiotics to be removed to a considerable degree (up to 95%). PMID:23369431

Efflux pump-deficient mutants as a platform to search for microbes that produce antibiotics

PubMed Central

Molina-Santiago, Carlos; Udaondo, Zulema; Daddaoua, Abdelali; Roca, Amalia; Martín, Jesús; Pérez-Victoria, Ignacio; Reyes, Fernando; Ramos, Juan-Luis

2015-01-01

Pseudomonas putida DOT-T1E-18 is a strain deficient in the major antibiotic efflux pump (TtgABC) that exhibits an overall increased susceptibility to a wide range of drugs when compared with the wild-type strain. We used this strain as a platform to search for microbes able to produce antibiotics that inhibit growth. A collection of 2400 isolates from soil, sediments and water was generated and a drop assay developed to identify, via growth inhibition halos, strains that prevent the growth of DOT-T1E-18 on solid Luria–Bertani plates. In this study, 35 different isolates that produced known and unknown antibiotics were identified. The most potent inhibitor of DOT-T1E-18 growth was an isolate named 250J that, through multi-locus sequence analysis, was identified as a Pseudomonas sp. strain. Culture supernatants of 250J contain four different xantholysins that prevent growth of Gram-positive bacteria, Gram-negative and fungi. Two of the xantholysins were produced in higher concentrations and purified. Xantholysin A was effective against Bacillus, Lysinibacillus and Rhodococcus strains, and the effect against these microbes was enhanced when used in combination with other antibiotics such as ampicillin, gentamicin and kanamycin. Xantholysin C was also efficient against Gram-positive bacteria and showed an interesting antimicrobial effect against Pseudomonas strains, and a synergistic inhibitory effect with ampicillin, chloramphenicol and gentamicin. PMID:26059350

Effect of different antibiotics on biofilm produced by uropathogenic Escherichia coli isolated from children with urinary tract infection.

PubMed

González, María José; Robino, Luciana; Iribarnegaray, Victoria; Zunino, Pablo; Scavone, Paola

2017-06-01

Recurrent urinary tract infections (UTIs) occur frequently in children and women. Intracellular bacterial communities (IBCs) and biofilm formation by Escherichia coli are risk factors for recurrence. The aim of this study was to evaluate the effect of different antibiotics on biofilms by E. coli strains isolated from children with UTI and to correlate virulence factors and IBCs with biofilm formation. A total of 116 E. coli strains were tested for biofilm formation using the crystal violet microplate technique. 58.6% of the strains did not produce biofilm, while 16.4%, 18.1% and 6.8% formed weak, moderate and strong biofilms, respectively. No correlation was found between the ability to form biofilms and the presence of IBCs. Biofilm formation was significantly associated with pili P codifying genes, whereas other virulence factors were not statistically associated. Antibiotics, including ampicillin, cephalothin, ceftriaxone, ceftazidime, amikacin and ciprofloxacin, were evaluated at different concentrations after 48 h of biofilm formation. Except ampicillin, the other antibiotics tested induced a significant reduction of biofilm biomass. In the case of recurrent UTIs potentially associated with the presence of biofilm, the use of third-generation cephalosporin, fluoroquinolones and aminoglycosides could be recommended. These antibiotics demonstrated to reduce biofilm biomass produced even by resistant strains. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The prevalence of antimicrobial-resistant Escherichia coli in two species of invasive alien mammals in Japan.

PubMed

Nakamura, Ichiro; Obi, Takeshi; Sakemi, Yoko; Nakayama, Ayano; Miyazaki, Kei; Ogura, Go; Tamaki, Masanobu; Oka, Tatsuzo; Takase, Kozo; Miyamoto, Atsushi; Kawamoto, Yasuhiro

2011-08-01

The prevalence of antimicrobial resistance in 128 Escherichia coli isolates was investigated in two species of invasive alien mammals (IAMs): the small Asian mongoose (SAM) and Japanese weasel (JW). The SAM is found on the main island of Okinawa, Japan, where a large number of livestock is available, and the JW is present on a small island, where is isolated from the main island, and have a small number of livestock. We focused on the two IAMs, inhabiting under the different environments, and compared their prevalence of antimicrobial-resistant E. coli. In the comparison of the frequencies of antimicrobial-resistant E. coli isolates between the SAM and JW, JW showed significantly higher prevalence of resistance against three drugs, ampicillin, chlortetracycline and nalidixic acid, compared with SAM's test results (P<0.05). The bla(TEM) gene and the aph1 gene were detected in 35 subjects (91%) of ampicillin-resistant isolates and 6 subjects (100%) of kanamycin-resistant isolates, respectively. The tet (A) gene was detected in 62 subjects (46%) of CTC-resistant isolates, and the tet (B) gene was detected in 25 subjects (8%) of those in IAM. The present results suggest that some IAMs were the carrier of antimicrobial-resistant bacteria and their genes, and the frequencies of these resistances were different between two IAM species.

Multidrug-Resistance and Toxic Metal Tolerance of Medically Important Bacteria Isolated from an Aquaculture System

PubMed Central

Resende, Juliana Alves; Silva, Vânia L.; Fontes, Cláudia Oliveira; Souza-Filho, Job Alves; de Oliveira, Tamara Lopes Rocha; Coelho, Cíntia Marques; César, Dionéia Evangelista; Diniz, Cláudio Galuppo

2012-01-01

The use of antimicrobials and toxic metals should be considered carefully in aquaculture and surrounding environments. We aimed to evaluate medically relevant bacteria in an aquaculture system and their susceptibility to antimicrobials and toxic metals. Selective cultures for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC) were obtained from water samples collected in two different year seasons. The isolated bacteria were biochemically identified and antimicrobial and toxic metal susceptibility patterns were determined. Overall, 407 representative strains were recovered. In general, bacteria isolated from fish ponds showed higher multiple antibiotic resistance indices when compared to those isolated from a water-fed canal. Resistance to penicillin and azithromycin was observed more frequently in the GPC group, whereas resistance to ampicillin and ampicillin/sulbactam or gentamicin was observed more frequently in the ENT and NFR groups, respectively. All the isolated bacteria were tolerant to nickel, zinc, chromium and copper at high levels (≥1,024 μg mL−1), whereas tolerance to cadmium and mercury varied among the isolated bacteria (2–1,024 μg mL−1). Multidrug-resistant bacteria were more frequent and diverse in fish ponds than in the water-fed canal. A positive correlation was observed between antimicrobial resistance and metal tolerance. The data point out the need for water treatment associated with the aquaculture system. PMID:22972388

In vitro effect of subminimal inhibitory concentrations of antibiotics on the biofilm formation ability of Acinetobacter baumannii clinical isolates.

PubMed

Bogdan, Maja; Drenjancevic, Domagoj; Harsanji Drenjancevic, Ivana; Bedenic, Branka; Zujic Atalic, Vlasta; Talapko, Jasminka; Vukovic, Dubravka

2018-02-01

The ability of A cinetobacter baumannii strains to form biofilm is one of the most important virulence factor which enables bacterial survival in a harsh environment and decreases antibiotic concentration as well. Subminimal inhibitory concentrations (subMICs) of antibiotics may change bacterial ultrastructure or have an influence on some different molecular mechanisms resulting in morphological or physiological changes in bacteria itself. The aim of this study was to determine effects of 1/2, 1/4, 1/8 and 1/16 minimal inhibitory concentrationsof imipenem, ampicillin-sulbactam, azithromycin, rifampicin and colistin on biofilm formation ability of 22 biofilm non-producing and 46 biofilm producing A. baumannii strains (30 weak producing strains and 16 moderate producing strains). Results of this study indicate that 1/2-1/16 MICs of imipenem, azithromycin, and rifampicin can reduce bacterial biofilm formation ability in moderate producing strains (p < 0.05), whereas 1/16 MIC of imipenem and 1/4-1/8 MICs of rifampicin reduce the biofilm formation in weak producing strains (p < 0.05). Statisticaly significant effect was detected among biofilm non-producing strains after their exposure to 1/16 MIC of azithromycin (p = 0.039). SubMICs of ampicillin-sulbactam and colistin did not have any significant effect on biofilm formation among tested A. baumannii strains.

Application of Nanoparticle Technology to Reduce the Anti-Microbial Resistance through β-Lactam Antibiotic-Polymer Inclusion Nano-Complex.

PubMed

Salamanca, Constain H; Yarce, Cristhian J; Roman, Yony; Davalos, Andrés F; Rivera, Gustavo R

2018-02-10

Biocompatible polymeric materials with potential to form functional structures in association with different therapeutic molecules have a high potential for biological, medical and pharmaceutical applications. Therefore, the capability of the inclusion of nano-Complex formed between the sodium salt of poly(maleic acid- alt -octadecene) and a β-lactam drug (ampicillin trihydrate) to avoid the chemical and enzymatic degradation and enhance the biological activity were evaluated. PAM-18Na was produced and characterized, as reported previously. The formation of polymeric hydrophobic aggregates in aqueous solution was determined, using pyrene as a fluorescent probe. Furthermore, the formation of polymer-drug nano-complexes was characterized by Differential Scanning Calorimetry-DSC, viscometric, ultrafiltration/centrifugation assays, zeta potential and size measurements were determined by dynamic light scattering-DLS. The PAM-18Na capacity to avoid the chemical degradation was studied through stress stability tests. The enzymatic degradation was evaluated from a pure β-lactamase, while the biological degradation was determined by different β-lactamase producing Staphylococcus aureus strains. When ampicillin was associated with PAM-18Na, the half-life time in acidic conditions increased, whereas both the enzymatic degradation and the minimum inhibitory concentration decreased to a 90 and 75%, respectively. These results suggest a promissory capability of this polymer to protect the β-lactam drugs against chemical, enzymatic and biological degradation.

Celecoxib Enhances the Efficacy of Low-Dose Antibiotic Treatment against Polymicrobial Sepsis in Mice and Clinical Isolates of ESKAPE Pathogens

PubMed Central

Annamanedi, Madhavi; Varma, Gajapati Y. N.; Anuradha, K.; Kalle, Arunasree M.

2017-01-01

Treatment of multidrug resistant bacterial infections has been a great challenge globally. Previous studies including our study have highlighted the use of celecoxib, a non-steroidal anti-inflammatory drug in combination with antibiotic has decreased the minimal inhibitory concentration to limit Staphylococcus aureus infection. However, the efficacy of this combinatorial treatment against various pathogenic bacteria is not determined. Therefore, we have evaluated the potential use of celecoxib in combination with low doses of antibiotic in limiting Gram-positive and Gram-negative bacteria in vivo in murine polymicrobial sepsis developed by cecum ligation and puncture (CLP) method and against clinically isolated human ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). The in vivo results clearly demonstrated a significant reduction in the bacterial load in different organs and in the inflammatory markers such as COX-2 and NF-κB via activation of SIRT1 in mice treated with imipenem, a choice of antibiotic for polymicrobial sepsis treatment. Combinatorial treatment of ampicillin and celecoxib was effective on clinical isolates of ESKAPE pathogens, 45% of tested clinical isolates showed more than 50% reduction in the colony forming units when compared to ampicillin alone. In conclusion, this non-traditional treatment strategy might be effective in clinic to reduce the dose of antibiotic to treat drug-resistant bacterial infections. PMID:28533769

Celecoxib Enhances the Efficacy of Low-Dose Antibiotic Treatment against Polymicrobial Sepsis in Mice and Clinical Isolates of ESKAPE Pathogens.

PubMed

Annamanedi, Madhavi; Varma, Gajapati Y N; Anuradha, K; Kalle, Arunasree M

2017-01-01

Treatment of multidrug resistant bacterial infections has been a great challenge globally. Previous studies including our study have highlighted the use of celecoxib, a non-steroidal anti-inflammatory drug in combination with antibiotic has decreased the minimal inhibitory concentration to limit Staphylococcus aureus infection. However, the efficacy of this combinatorial treatment against various pathogenic bacteria is not determined. Therefore, we have evaluated the potential use of celecoxib in combination with low doses of antibiotic in limiting Gram-positive and Gram-negative bacteria in vivo in murine polymicrobial sepsis developed by cecum ligation and puncture (CLP) method and against clinically isolated human ESKAPE pathogens ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa , and Enterobacter species). The in vivo results clearly demonstrated a significant reduction in the bacterial load in different organs and in the inflammatory markers such as COX-2 and NF-κB via activation of SIRT1 in mice treated with imipenem, a choice of antibiotic for polymicrobial sepsis treatment. Combinatorial treatment of ampicillin and celecoxib was effective on clinical isolates of ESKAPE pathogens, 45% of tested clinical isolates showed more than 50% reduction in the colony forming units when compared to ampicillin alone. In conclusion, this non-traditional treatment strategy might be effective in clinic to reduce the dose of antibiotic to treat drug-resistant bacterial infections.

Flow cytometric evaluation of antibiotic effects on viability and mitochondrial function of refrigerated spermatozoa of Nile tilapia

USGS Publications Warehouse

Segovia, M.; Jenkins, J.A.; Paniagua-Chavez, C.; Tiersch, T.R.

2000-01-01

Improved techniques for storage and evaluation of fish sperm would enhance breeding programs around the world. The goal of this study was to test the effect of antibiotics on refrigerated sperm from Nile tilapia (Oreochromis niloticus) by use of flow cytometry with 2 dual-staining protocols for objective assessment of sperm quality. Concentrations of 1 x 109 sperm/mL were suspended in Ringer's buffer at 318 mOsmol/kg (pH 8.0). The fluorescent stains Sybr 14 (10 ??M), propidium iodide (2.4 mM), and rhodamine 123 (0.13 ??M) were used to assess cell viability and mitochondrial function. Three concentrations of ampicillin, gentamicin, and an antibiotic/antimycotic solution were added to fresh spermatozoa. Motility estimates and flow cytometry measurements were made daily during 7 d of refrigerated storage (4 ??C). The highest concentrations of gentamicin and antibiotic/antimycotic and all 3 concentrations of ampicillin significantly reduced sperm viability. The highest of each of the 3 antibiotic concentrations significantly reduced mitochondrial function. This study demonstrates that objective sperm quality assessments can be made using flow cytometry and that addition of antibiotics at appropriate concentrations can lengthen refrigerated storage time for tilapia spermatozoa. With minor modifications, these protocols can be adapted for use with sperm from other species and with other tissue types.

Application of Nanoparticle Technology to Reduce the Anti-Microbial Resistance through β-Lactam Antibiotic-Polymer Inclusion Nano-Complex

PubMed Central

Yarce, Cristhian J.; Roman, Yony; Davalos, Andrés F.; Rivera, Gustavo R.

2018-01-01

Biocompatible polymeric materials with potential to form functional structures in association with different therapeutic molecules have a high potential for biological, medical and pharmaceutical applications. Therefore, the capability of the inclusion of nano-Complex formed between the sodium salt of poly(maleic acid-alt-octadecene) and a β-lactam drug (ampicillin trihydrate) to avoid the chemical and enzymatic degradation and enhance the biological activity were evaluated. PAM-18Na was produced and characterized, as reported previously. The formation of polymeric hydrophobic aggregates in aqueous solution was determined, using pyrene as a fluorescent probe. Furthermore, the formation of polymer-drug nano-complexes was characterized by Differential Scanning Calorimetry-DSC, viscometric, ultrafiltration/centrifugation assays, zeta potential and size measurements were determined by dynamic light scattering-DLS. The PAM-18Na capacity to avoid the chemical degradation was studied through stress stability tests. The enzymatic degradation was evaluated from a pure β-lactamase, while the biological degradation was determined by different β-lactamase producing Staphylococcus aureus strains. When ampicillin was associated with PAM-18Na, the half-life time in acidic conditions increased, whereas both the enzymatic degradation and the minimum inhibitory concentration decreased to a 90 and 75%, respectively. These results suggest a promissory capability of this polymer to protect the β-lactam drugs against chemical, enzymatic and biological degradation. PMID:29439391

D-alanine carboxypeptidase activity of Micrococcus lysodeikticus released into the protoplasting medium.

PubMed

Linder, R; Salton, M R

1975-06-16

Conversion of whole cells of Micrococcus lysodeikticus to protoplasts allowed the release of a soluble form of a D-alanine carboxypeptidase into the protoplasting medium. The enzyme cleaves the terminal D-alanine from the radioactively labelled UDP-N-acetylmuramyl-pentapeptide containing L-lysine as the diamino acid. However, the enzyme is only minimally active in this fraction so that it had to be enriched and partially purified before its properties could be studied. Chromatography on carboxymethyl-Sephadex removed the lysozyme used in the protoplasting of the cells. The material which was unadsorbed to the column was applied to an affinity chromatography column of Ampicillin-Sepharose. Most of the contaminating protein was washed from the column while the D-alanine carboxypeptidase adhered to the resin and could be eluted with 0.5 M Tris-HCl buffer pH 8.6. Some of the properties of the enzymic activity were studied using this preparation. The enzyme was activated by Mg2+ ions with a broad optimum from 15--35 mM. It was maximally active when NaCl at a concentrations of 0.06--0.08 M was added to the assay, and the pH curve was biphasic with an alkaline optimum. The Km for substrate was found to be 0.118 mM. Enzymic activity was completely inhibited by low concentrations of Ampicillin and penicillin G.

Analysis of Haemophilus influenzae serotype f isolated from three Japanese children with invasive H. influenzae infection.

PubMed

Hoshino, Tadashi; Hachisu, Yushi; Kikuchi, Takashi; Tokutake, Shoko; Okui, Hideyuki; Kutsuna, Satoru; Fukasawa, Chie; Murayama, Kei; Oohara, Asami; Shimizu, Hiroyuki; Ito, Midori; Takahashi, Yoshiko; Ishiwada, Naruhiko

2015-04-01

In Japan, publicly subsidized Haemophilus influenzae serotype b vaccines became available in 2011; consequently, the incidence of invasive H. influenzae infection in paediatric patients of less than 5 years of age decreased dramatically. In 2013, the first case of H. influenzae serotype f (Hif) meningitis in a Japanese infant was reported, and another case of Hif meningitis in a Japanese infant was observed in 2013. We experienced a fatal paediatric case of Hif bacteraemia in 2004; therefore, we conducted an analysis of the three Hif strains isolated from these three Japanese children with invasive Hif infections. All three strains were β-lactamase-non-producing, ampicillin-sensitive strains, with MICs of 1 µg ml(-1) or less. However, one of the three strains showed slightly elevated MICs for ampicillin (1 µg ml(-1)), cefotaxime (0.25 µg ml(-1)) and meropenem (0.13 µg ml(-1)). A molecular analysis by multilocus sequence typing identified all three strains as sequence type (ST) 124, which is a predominant invasive Hif strain in many countries. SmaI-digested PFGE showed variable DNA fragmentation patterns among the strains, suggesting that some highly virulent strains have originated from a single ST124 clone and caused invasive Hif infections in Japan. Additional studies are needed to determine the factors that have led to the clonal expansion of virulent ST124 strains. © 2015 The Authors.

A single-center experience of antimicrobial resistance patterns in pediatric urinary tract infection.

PubMed

Senel, Saliha; Karacan, Candemir; Erkek, Nilgun; Gol, Nese

2010-01-01

To assess the prevalence of urinary tract pathogens and their resistance patterns against antimicrobial agents in a single center. In children <16 years of age admitted for urinary tract infection (UTI) to the Dr. Sami Ulus Teaching and Training Hospital from January 2004 to December 2008, positive urine cultures were reviewed. A total of 3,485 positive urine cultures were identified, of which 2,379 (68%) were from females and 106 (32%) from males. Their mean age was 63.5 +/- 40.7 months. Escherichia coli was the most common causative agent both in total and among different age groups. Ampicillin had the highest resistance rate from all the pathogens isolated (63.8%), followed by piperacillin (51.8%) and trimethoprim-sulfamethoxazole (TMP-SMX; 48.6%). Cephalotin also had a high resistance rate (32.7%). The least resistance was for imipenem, amikacin, netilmicin and ciprofloxacin (0.13, 1.7, 2.4 and 7.5%, respectively). None of the Klebsiella and Pseudomonas isolates were resistant to imipenem. None of the Staphylococcus aureus isolates were resistant to teicoplanin and vancomycin. Vancomycin-resistant Enterococcus spp. were isolated from two cultures. E. coli was the most common causative agent of UTI in children. Ampicillin, TMP-SMX or cephalothin and piperacillin had the highest resistance rates against urinary tract pathogens in our center. Copyright 2010 S. Karger AG, Basel.

Infants under two months of age with urinary tract infections are showing increasing resistance to empirical and oral antibiotics.

PubMed

Segal, Zvi; Cohen, Matan J; Engelhard, Dan; Tenenbaum, Ariel; Simckes, Ari M; Benenson, Shmuel; Stepensky, Polina; Averbuch, Diana

2016-04-01

Data on antimicrobial resistance in uropathogens in infants up to the age of three months are limited. This study characterised resistance patterns in Gram-negative uropathogens in infants up to the age of two months. Previously healthy young infants with urinary tract infections (UTIs) were studied retrospectively. Antimicrobial susceptibility was evaluated. Multidrug resistance (MDR) was defined as resistance to at least three antibiotic classes. Clinical, laboratory and outcome data were compared between infants with UTIs caused by bacteria sensitive and resistant to empirical and to oral therapy. We evaluated 306 UTI episodes with 314 pathogens. The following resistance rates were observed: ampicillin 73.7%, cefazoline 22.1%, ampicillin/clavulanate 21.8%, cefuroxime 7.8%, gentamicin 7%; MDR 11.8%; resistant to empirical treatment 7.3% and resistant to available oral antibiotics 8.6%. Our study showed that pathogens resistant to empirical and oral therapy were more frequently isolated in non-Jewish (Arab) infants and in those of ≥30 days of age. Resistance to empirical treatment and oral antibiotics also resulted in longer mean hospital stays. Resistance to antibiotics challenges empirical therapy and compromises oral treatment options in young infants with UTIs. Antimicrobial resistance patterns should be monitored in infants to determine appropriate empirical antibiotic therapy protocols. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Investigation and Treatment of Fusidic Acid Resistance Among Methicillin-Resistant Staphylococcal Isolates from Egypt.

PubMed

Abouelfetouh, Alaa; Kassem, Mervat; Naguib, Marwa; El-Nakeeb, Moustafa

2017-01-01

Methicillin resistance among staphylococci isolated from patients in northern Egypt has escalated alarmingly in the past decade. Data about the prevalence of fusidic acid (FA) resistance in Egyptian clinical isolates are limited. This work investigates the prevalence and mechanism of FA resistance among 81 methicillin-resistant staphylococcal isolates from major hospitals of Alexandria, Egypt. Some combinations for treating infections due to resistant isolates were studied. Twenty-six isolates (32.1%) were FA resistant (minimum inhibitory concentrations [MICs] = 2-1,024 μg/ml), and fusB and fusC genes coding for FA resistance were detected in 30.77% and 34.62% of the FA-resistant strains, respectively. One highly resistant isolate, S502 (MIC = 1,024 μg/ml), possessed both genes. Plasmid curing resulted in fusB loss and MIC decrease by 16-64 folds. Conjugation caused acquisition of FA resistance among susceptible isolates. Serial passages in subinhibitory FA concentrations produced mutants with increased MIC by 4-32 folds. The combination of FA with rifampin, gentamicin, or ampicillin/sulbactam, in a subinhibitory concentration, was synergistic against the isolates, including serial passage mutants, decreasing number of survivors by an average of 2-4 logs. A relatively moderate rate of FA resistance was detected in Alexandria hospitals. Combination therapy with gentamicin, rifampin, or ampicillin/sulbactam is crucial to preserve the effectiveness of FA.

R-plasmid transfer in a wastewater treatment plant.

PubMed Central

Mach, P A; Grimes, D J

1982-01-01

Enteric bacteria have been examined for their ability to transfer antibiotic resistance in a wastewater treatment plant. Resistant Salmonella enteritidis, Proteus mirabilis, and Escherichia coli were isolated from clinical specimens and primary sewage effluent. Resistance to ampicillin, chloramphenicol, streptomycin, sulfadiazine, and tetracycline was demonstrated by spread plate and tube dilution techniques. Plasmid mediation of resistance was shown by ethidium bromide curing, agarose gel electrophoresis, and direct cell transfer. Each donor was mated with susceptible E. coli and Shigella sonnei. Mating pairs (and recipient controls) were suspended in unchlorinated primary effluent that had been filtered and autoclaved. Suspensions were added to membrane diffusion chambers which were then placed in the primary and secondary setting tanks of the wastewater treatment plant. Resistant recombinants were detected by replica plating nutrient agar master plates onto xylose lysine desoxycholate agar plates that contained per milliliter of medium 10 micrograms of ampicillin, 30 micrograms of chloramphenicol, 10 micrograms of streptomycin, 100 micrograms of sulfadiazine, or 30 micrograms of tetracycline. Mean transfer frequencies for laboratory matings were 2.1 X 10(-3). In situ matings for primary and secondary settling resulted in frequencies of 4.9 X 10(-5) and 7.5 X 10(-5), respectively. These values suggest that a significant level of resistance transfer occurs in wastewater treatment plants in the absence of antibiotics as selective agents. Images PMID:6760813

Antimicrobial resistance in Shigella spp. causing traveller's diarrhoea (1995-2010): a retrospective analysis.

PubMed

Pons, M J; Gomes, C; Martínez-Puchol, S; Ruiz, L; Mensa, L; Vila, J; Gascón, J; Ruiz, J

2013-01-01

Shigellosis is a global human health problem causing an important morbidity among travellers returning from tropical areas. This study was aimed to describe the evolution of antimicrobial resistance profile in Shigella spp. isolated between the years 1995-2010 in patients with traveller's diarrhoea (TD) returning from tropical areas. The levels of antimicrobial resistance were tested in a total of 191 Shigella spp. isolated during the period from 1995 to 2010. A decrease of cases of diarrhoea caused by Shigella has been observed in recent years. A wide spectrum of antibiotic resistance was observed among Shigella spp. These isolates showed high levels of resistance to tetracycline (84%), co-trimoxazole (75.5%), and ampicillin (45.5%). The resistance was low to ciprofloxacin (2.1%), azithromycin (3.9%) and furazolidone (8.4%). According to the period, in the case of ampicillin, amoxicillin plus clavulanic acid, chloramphenicol, values of resistance were significantly decreasing from 1995-2000 to 2001-2010, (62.5% vs. 28.4%, 19.8% vs. 6.6%, 23.4 vs. 10.4%, respectively). Meanwhile in nalidixic acid and tetracycline the evolution of resistance has increased over time. A decrease in the isolation number of Shigella spp. causing TD has been observed. Differential trends in the evolution of the levels of resistance to the tested antibacterial agents have been observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Changes of resistant phenotype and CRISPR/Cas system of four Shigella strains passaged for 90 times without antibiotics].

PubMed

Zhang, B; Hong, L J; Duan, G C; Liang, W J; Yang, H Y; Xi, Y L

2017-02-10

Objective: To explore the stability of resistant phenotypes and changes of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) gene system on four Shigella strains in the absence of antibiotics. Methods: Four clinical isolated Shigella strains that resistant to different antibiotics were consecutive passaged for 90 times without antibiotics. Agar dilution method was used to determine the minimum inhibitory concentration of Shigella strains. After sequence analysis with PCR, CRISPR Finder and Clustal X 2.1 were applied to identify the changes of CRISPR loci in the Shigella strains. Results: After the consecutive transfer of 90 generations, sensitivity to certain antibiotics of four Shigella strains with different drug resistant spectrums increased. Mel-sf1998024/zz resistance to ampicillin, cephalexin, cefotaxime, chloramphenicol decreased, mel-s2014026/sx resistance to norfloxacin, trimethoprim decreased, mel-sf2004004/sx drug resistance to ampicillin, cefuroxime, cefotaxime, chloramphenicol, trimethoprim decreased and mel-sf2013004/bj resistance to chloramphenicol decreased. The spacer of which matched gene codes Cas and its upstream repeat in 3'end of CRISPR3 got lost in mel-sf1998024/zz and mel-sf2013004/bj. Conclusions: Shigella strains could reduce or lose their resistance to some antibiotics after consecutive transfers, without the interference of antibiotics. CRISPR3 locus had dynamic spacers in Shigella strains while CRISPR3 locus and cas genes might have been co-evolved.

Dichromatic and monochromatic laser radiation effects on antibiotic resistance, biofilm formation, and division rate of Pantoea agglomerans

NASA Astrophysics Data System (ADS)

Thomé, A. M. C.; Souza, B. P.; Mendes, J. P. M.; Cardoso, A. F. R.; Soares, L. C.; Trajano, E. T. L.; Fonseca, A. S.

2018-06-01

Since infection is a common cause of delayed wound healing, it is important to understand the effect of low-level laser therapy (LLLT) in bacterial mechanisms. In this study we evaluated the effects of LLLT on antibiotic resistance, division rate, and biofilm formation of Pantoea agglomerans. P. agglomerans samples were isolated from human pressure injuries in humans and cultures were exposed to low-level monochromatic and simultaneous dichromatic laser radiation to study the susceptibility of an antimicrobial to ampicillin and piperacillin  +  tazobactam, quantification of areas of bacterial colonies, and biofilm formation of bacterial cells. Fluence, wavelength, and emission mode were used in the therapeutic protocols for wound healing. The data showed no changes in the areas of the colonies, but dichromatic laser radiation decreased biofilm formation, while a monochromatic red laser at low dose increased biofilm formation and infrared at high dose decreased antibiotic resistance to ampicillin. LLLT modulates antibiotic resistance and biofilm formation of P. agglomerans, but these depend on the laser irradiation parameters, since dichromatic laser radiation induces biological effects that differ from those induced by monochromatic laser radiation. Thus, simultaneous dichromatic low-level red and infrared lasers could be a new option for the treatment of infected wounds, reducing biofilm formation, without altering antibiotic resistance and the division rate of P. agglomerans cultures.

Functional and structural characterization of a novel putative cysteine protease cell wall-modifying multi-domain enzyme selected from a microbial metagenome.

PubMed

Faheem, Muhammad; Martins-de-Sa, Diogo; Vidal, Julia F D; Álvares, Alice C M; Brandão-Neto, José; Bird, Louise E; Tully, Mark D; von Delft, Frank; Souto, Betulia M; Quirino, Betania F; Freitas, Sonia M; Barbosa, João Alexandre R G

2016-12-09

A current metagenomics focus is to interpret and transform collected genomic data into biological information. By combining structural, functional and genomic data we have assessed a novel bacterial protein selected from a carbohydrate-related activity screen in a microbial metagenomic library from Capra hircus (domestic goat) gut. This uncharacterized protein was predicted as a bacterial cell wall-modifying enzyme (CWME) and shown to contain four domains: an N-terminal, a cysteine protease, a peptidoglycan-binding and an SH3 bacterial domain. We successfully cloned, expressed and purified this putative cysteine protease (PCP), which presented autoproteolytic activity and inhibition by protease inhibitors. We observed cell wall hydrolytic activity and ampicillin binding capacity, a characteristic of most bacterial CWME. Fluorimetric binding analysis yielded a K b of 1.8 × 10 5  M -1 for ampicillin. Small-angle X-ray scattering (SAXS) showed a maximum particle dimension of 95 Å with a real-space R g of 28.35 Å. The elongated molecular envelope corroborates the dynamic light scattering (DLS) estimated size. Furthermore, homology modeling and SAXS allowed the construction of a model that explains the stability and secondary structural changes observed by circular dichroism (CD). In short, we report a novel cell wall-modifying autoproteolytic PCP with insight into its biochemical, biophysical and structural features.

Occurrence and Distribution of Antibiotic-resistant Bacteria and Transfer of Resistance Genes in Lake Taihu

PubMed Central

Yin, Qian; Yue, Dongmei; Peng, Yuke; Liu, Ying; Xiao, Lin

2013-01-01

The overuse of antibiotics has accelerated antibiotic resistance in the natural environment, especially fresh water, generating a potential risk for public health around the world. In this study, antibiotic resistance in Lake Taihu was investigated and this was the first thorough data obtained through culture-dependent methods. High percentages of resistance to streptomycin and ampicillin among bacterial isolates were detected, followed by tetracycline and chloramphenicol. Especially high levels of ampicillin resistance in the western and northern regions were illustrated. Bacterial identification of the isolates selected for further study indicated the prevalence of some opportunistic pathogens and 62.0% of the 78 isolates exhibited multiple antibiotic resistance. The presence of ESBLs genes was in the following sequence: blaTEM > blaSHV > blaCTMX and 38.5% of the isolates had a class I integrase gene. Of all tested strains, 80.8% were able to transfer antibiotic resistance through conjugation. We also concluded that some new families of human-associated ESBLs and AmpC genes can be found in natural environmental isolates. The prevalence of antibiotic resistance and the dissemination of transferable antibiotic resistance in bacterial isolates (especially in opportunistic pathogens) was alarming and clearly indicated the urgency of realizing the health risks of antibiotic resistance to human and animal populations who are dependent on Lake Taihu for water consumption. PMID:24240317

Gut microbiota of Tenebrio molitor and their response to environmental change.

PubMed

Jung, Jaejoon; Heo, Aram; Park, Yong Woo; Kim, Ye Ji; Koh, Hyelim; Park, Woojun

2014-07-01

A bacterial community analysis of the gut of Tenebrio molitor larvae was performed using pyrosequencing of the 16S rRNA gene. A predominance of genus Spiroplasma species in phylum Tenericutes was observed in the gut samples, but there was variation found in the community composition between T. molitor individuals. The gut bacteria community structure was not significantly affected by the presence of antibiotics or by the exposure of T. molitor larvae to a highly diverse soil bacteria community. A negative relationship was identified between bacterial diversity and ampicillin concentration; however, no negative relationship was identified with the addition of kanamycin. Ampicillin treatment resulted in a reduction in the bacterial community size, estimated using the 16S rRNA gene copy number. A detailed phylogenetic analysis indicated that the Spiroplasma-associated sequences originating from the T. molitor larvae were distinct from previously identified Spiroplasma type species, implying the presence of novel Spiroplasma species. Some Spiroplasma species are known to be insect pathogens; however, the T. molitor larvae did not experience any harmful effects arising from the presence of Spiroplasma species, indicating that Spiroplasma in the gut of T. molitor larvae do not act as a pathogen to the host. A comparison with the bacterial communities found in other insects (Apis and Solenopsis) showed that the Spiroplasma species found in this study were specific to T. molitor.

Dimethyl Sulfoxide Protects Escherichia coli from Rapid Antimicrobial-Mediated Killing

PubMed Central

Mi, Hongfei; Wang, Dai; Xue, Yunxin; Zhang, Zhi; Hong, Yuzhi; Drlica, Karl

2016-01-01

The contribution of reactive oxygen species (ROS) to antimicrobial lethality was examined by treating Escherichia coli with dimethyl sulfoxide (DMSO), an antioxidant solvent frequently used in antimicrobial studies. DMSO inhibited killing by ampicillin, kanamycin, and two quinolones and had little effect on MICs. DMSO-mediated protection correlated with decreased ROS accumulation and provided evidence for ROS-mediated programmed cell death. These data support the contribution of ROS to antimicrobial lethality and suggest caution when using DMSO-dissolved antimicrobials for short-time killing assays. PMID:27246776

Inhibition of bacterial multidrug resistance by celecoxib, a cyclooxygenase-2 inhibitor.

PubMed

Kalle, Arunasree M; Rizvi, Arshad

2011-01-01

Multidrug resistance (MDR) is a major problem in the treatment of infectious diseases and cancer. Accumulating evidence suggests that the cyclooxygenase-2 (COX-2)-specific inhibitor celecoxib would not only inhibit COX-2 but also help in the reversal of drug resistance in cancers by inhibiting the MDR1 efflux pump. Here, we demonstrate that celecoxib increases the sensitivity of bacteria to the antibiotics ampicillin, kanamycin, chloramphenicol, and ciprofloxacin by accumulating the drugs inside the cell, thus reversing MDR in bacteria.

Listeriosis: Is It a Rare Disease in Thailand?

PubMed

Lawtongkum, Weerasak; Thisyakorn, Usa

2016-02-01

The prevalence of Listeria monocytogenes infection has been characterized as rare in Thailand. Within one month, 3 cases of listeriosis were seen at Vachira Phuket Hospital in Phuket, Thailand. Two cases were neonates with septicemia, of which one made an uneventful recovery and the other expired. The third case was an eleven-year-old boy with meningitis who also succumbed to his illness. All isolated L. monocytogenes were sensitive to ampicillin. An outbreak investigation revealed no L. monocytogenes contamination in tested food sources in Phuket.

Development of Effective Aerobic Cometabolic Systems for the In Situ Transformation of Problematic Chlorinated Solvent Mixtures

DTIC Science & Technology

2005-02-01

vector contained the ampicillin resistance gene , only transformed colonies should grow on the plates and since the inserted DNA should have knocked...flava 340 209 203 69 2422 Nitrogen-fixing bacterium MI753 340 209 203 69 2571 Pseudomonas spinosa 340 209 203 217 2458 Xylophilus ampelinus 340 209...277 203 198 2767 Unidentified bacterium 340 277 203 198 2674 Type 0803 filamentous bacterium 340 277 203 198 2581 Xylophilus ampelinus 340 209 203 217

Subdural abscess secondary to covert dental sepsis

PubMed Central

Sprott, Mae S.; Hall, K.; Newman, P. K.; Welbury, R. R.; Ingham, H. R.

1981-01-01

The bacterial flora of a subdural abscess in a 17-year-old male, with radiological evidence of unilateral infection of the maxillary and frontal air sinuses, was typical of that encountered in the dental sulcus. Extensive examination revealed no primary focus of infection other than apical infection in the 2 upper first molar teeth, which were extracted. Treatment with ampicillin, gentamicin and metronidazole rapidly controlled the subdural infection, and resolution, as evidenced by computerized tomography, was complete at 10 months. PMID:7335566

Chemotherapy of Bacterial Plasmids

DTIC Science & Technology

1979-01-29

of drug resistance is interrupted 1960 Fukasawa. Watanabe by blender treatment of mixed cultures The term " R-factor" is introduced for the 1960 M ...bacterial . -.co DNA biosynthesis (rev. in [53]). At a concentration oI I!319- M tl:2 -,- O Oil of 6.25x 106 ,l1which did not inhibit the growth A of...sensitized 96 15;! .,\\litsuhdshi. S . I~ohe. S.. Inoue. M :bi, _"). 131 (1976, those bacteria to inhibitions by ampicillin and cepha- -. ~ J.. et al .J

Biochemical Characterization of VIM-39, a VIM-1-Like Metallo-β-Lactamase Variant from a Multidrug-Resistant Klebsiella pneumoniae Isolate from Greece.

PubMed

Papagiannitsis, Costas C; Pollini, Simona; De Luca, Filomena; Rossolini, Gian Maria; Docquier, Jean-Denis; Hrabák, Jaroslav

2015-12-01

VIM-39, a VIM-1-like metallo-β-lactamase variant (VIM-1 Thr33Ala His224Leu) was identified in a clinical isolate of Klebsiella pneumoniae belonging to sequence type 147. VIM-39 hydrolyzed ampicillin, cephalothin, and imipenem more efficiently than did VIM-1 and VIM-26 (a VIM-1 variant with the His224Leu substitution) because of higher turnover rates. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

High-pressure liquid chromatography analysis of antibiotic susceptibility disks.

PubMed Central

Hagel, R B; Waysek, E H; Cort, W M

1979-01-01

The analysis of antibiotic susceptibility disks by high-pressure liquid chromatography (HPLC) was investigated. Methods are presented for the potency determination of mecillinam, ampicillin, carbenicillin, and cephalothin alone and in various combinations. Good agreement between HPLC and microbiological data is observed for potency determinations with recoveries of greater than 95%. Relative standard deviations of lower than 2% are recorded for each HPLC method. HPLC methods offer improved accuracy and greater precision when compared to the standard microbiological methods of analysis for susceptibility disks. PMID:507793

Genomic Approaches for Detection and Treatment of Breast Cancer

DTIC Science & Technology

2007-07-01

The T7Select 10-3b system of lytic phage display is a mid-copy vector that displays between 5-15 copies on the surface of the T7 capsid. The natural... Phage are amplified on a bacterial host that carries an ampicillin-resistant plasmid expressing additional 10A capsid protein from a T7 promoter. We... phage display library of coding fragments encompassing all open reading frames of the human genome. We designed approximately 467,000 overlapping

Beta-lactam antibiotics modulate T-cell functions and gene expression via covalent binding to cellular albumin.

PubMed

Mor, Felix; Cohen, Irun R

2013-02-19

Recent work has suggested that beta-lactam antibiotics might directly affect eukaryotic cellular functions. Here, we studied the effects of commonly used beta-lactam antibiotics on rodent and human T cells in vitro and in vivo on T-cell-mediated experimental autoimmune diseases. We now report that experimental autoimmune encephalomyelitis and adjuvant arthritis were significantly more severe in rats treated with cefuroxime and other beta-lactams. T cells appeared to mediate the effect: an anti-myelin basic protein T-cell line treated with cefuroxime or penicillin was more encephalitogenic in adoptive transfer experiments. The beta-lactam ampicillin, in contrast to cefuroxime and penicillin, did not enhance encephalomyelitis, but did inhibit the autoimmune diabetes developing spontaneously in nonobese diabetic mice. Gene expression analysis of human peripheral blood T cells showed that numerous genes associated with T helper 2 (Th2) and T regulatory (Treg) differentiation were down-regulated in T cells stimulated in the presence of cefuroxime; these genes were up-regulated in the presence of ampicillin. The T-cell protein that covalently bound beta-lactam antibiotics was found to be albumin. Human and rodent T cells expressed albumin mRNA and protein, and penicillin-modified albumin was taken up by rat T cells, leading to enhanced encephalitogenicity. Thus, beta-lactam antibiotics in wide clinical use have marked effects on T-cell behavior; beta-lactam antibiotics can function as immunomodulators, apparently through covalent binding to albumin.

Comparative analysis of antimicrobial resistance in enterotoxigenic Escherichia coli isolates from two paediatric cohort studies in Lima, Peru

PubMed Central

Medina, Anicia M.; Rivera, Fulton P.; Pons, Maria J.; Riveros, Maribel; Gomes, Cláudia; Bernal, María; Meza, Rina; Maves, Ryan C.; Huicho, Luis; Chea-Woo, Elsa; Lanata, Claudio F.; Gil, Ana I.; Ochoa, Theresa J.; Ruiz, Joaquim

2015-01-01

Background Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children <24 months in Lima, Peru. Methods ETEC were identified by an in-house multiplex real-time PCR. Susceptibility to 13 antimicrobial agents was tested by disk diffusion; mechanisms of resistance were evaluated by PCR. Results ETEC isolates were resistant to ampicillin (64%), cotrimoxazole (52%), tetracycline (37%); 39% of the isolates were multidrug-resistant. Heat-stable toxin producing (ETEC-st) (48%) and heat-labile toxin producing ETEC (ETEC-lt) (40%) had higher rates of multidrug resistance than isolates producing both toxins (ETEC-lt-st) (21%), p<0.05. Only 10% of isolates were resistant to nalidixic acid and none to ciprofloxacin or cefotaxime. Ampicillin and sulfamethoxazole resistance were most often associated with blaTEM (69%) and sul2 genes (68%), respectively. Tetracycline resistance was associated with tet(A) (49%) and tet(B) (39%) genes. Azithromycin inhibitory diameters were ≤15 mm in 36% of isolates, with 5% of those presenting the mph(A) gene. Conclusions ETEC from Peruvian children are often resistant to older, inexpensive antibiotics, while remaining susceptible to ciprofloxacin, cephalosporins and furazolidone. Fluoroquinolones and azithromycin remain the drugs of choice for ETEC infections in Peru. However, further development of resistance should be closely monitored. PMID:26175267

Comparison of Disk Diffusion, VITEK 2, and Broth Microdilution Antimicrobial Susceptibility Test Results for Unusual Species of Enterobacteriaceae▿

PubMed Central

Stone, Nimalie D.; O'Hara, Caroline M.; Williams, Portia P.; McGowan, John E.; Tenover, Fred C.

2007-01-01

We compared the antimicrobial susceptibility testing results generated by disk diffusion and the VITEK 2 automated system with the results of the Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) reference method for 61 isolates of unusual species of Enterobacteriaceae. The isolates represented 15 genera and 26 different species, including Buttiauxella, Cedecea, Kluyvera, Leminorella, and Yokenella. Antimicrobial agents included aminoglycosides, carbapenems, cephalosporins, fluoroquinolones, penicillins, and trimethoprim-sulfamethoxazole. CLSI interpretative criteria for Enterobacteriaceae were used. Of the 12 drugs tested by BMD and disk diffusion, 10 showed >95% categorical agreement (CA). CA was lower for ampicillin (80.3%) and cefazolin (77.0%). There were 3 very major errors (all with cefazolin), 1 major error (also with cefazolin), and 26 minor errors. Of the 40 isolates (representing 12 species) that could be identified with the VITEK 2 database, 36 were identified correctly to species level, 1 was identified to genus level only, and 3 were reported as unidentified. VITEK 2 generated MIC results for 42 (68.8%) of 61 isolates, but categorical interpretations (susceptible, intermediate, and resistant) were provided for only 22. For the 17 drugs tested by both BMD and VITEK 2, essential agreement ranged from 80.9 to 100% and CA ranged from 68.2% (ampicillin) to 100%; thirteen drugs exhibited 100% CA. In summary, disk diffusion provides a reliable alternative to BMD for testing of unusual Enterobacteriaceae, some of which cannot be tested, or produce incorrect results, by automated methods. PMID:17135429

Oral antibiotics enhance antibody responses to keyhole limpet hemocyanin in orally but not muscularly immunized chickens.

PubMed

Murai, Atsushi; Kitahara, Kazuki; Okumura, Shouta; Kobayashi, Misato; Horio, Fumihiko

2016-02-01

Recent studies have emphasized the crucial role of gut microbiota in triggering and modulating immune response. We aimed to determine whether the modification of gut microbiota by oral co-administration of two antibiotics, ampicillin and neomycin, would lead to changes in the antibody response to antigens in chickens. Neonatal chickens were given or not given ampicillin and neomycin (0.25 and 0.5 g/L, respectively) in drinking water. At 2 weeks of age, the chicks were muscularly or orally immunized with antigenic keyhole limpet hemocyanin (KLH), and then serum anti-KLH antibody levels were examined by ELISA. In orally immunized chicks, oral antibiotics treatment enhanced antibody responses (IgM, IgA, IgY) by 2-3-fold compared with the antibiotics-free control, while the antibiotics did not enhance antibody responses in the muscularly immunized chicks. Concomitant with their enhancement of antibody responses, the oral antibiotics also lowered the Lactobacillus species in feces. Low doses of antibiotics (10-fold and 100-fold lower than the initial trial), which failed to change the fecal Lactobacillus population, did not modify any antibody responses when chicks were orally immunized with KLH. In conclusion, oral antibiotics treatment enhanced the antibody response to orally exposed antigens in chickens. This enhancement of antibody response was associated with a modification of the fecal Lactobacillus content, suggesting a possible link between gut microbiota and antibody response in chickens. © 2015 Japanese Society of Animal Science.

A probabilistic approach to assess antibiotic resistance development risks in environmental compartments and its application to an intensive aquaculture production scenario.

PubMed

Rico, Andreu; Jacobs, Rianne; Van den Brink, Paul J; Tello, Alfredo

2017-12-01

Estimating antibiotic pollution and antibiotic resistance development risks in environmental compartments is important to design management strategies that advance our stewardship of antibiotics. In this study we propose a modelling approach to estimate the risk of antibiotic resistance development in environmental compartments and demonstrate its application in aquaculture production systems. We modelled exposure concentrations for 12 antibiotics used in Vietnamese Pangasius catfish production using the ERA-AQUA model. Minimum selective concentration (MSC) distributions that characterize the selective pressure of antibiotics on bacterial communities were derived from the European Committee on Antimicrobial Susceptibility Testing (EUCAST) Minimum Inhibitory Concentration dataset. The antibiotic resistance development risk (RDR) for each antibiotic was calculated as the probability that the antibiotic exposure distribution exceeds the MSC distribution representing the bacterial community. RDRs in pond sediments were nearly 100% for all antibiotics. Median RDR values in pond water were high for the majority of the antibiotics, with rifampicin, levofloxacin and ampicillin having highest values. In the effluent mixing area, RDRs were low for most antibiotics, with the exception of amoxicillin, ampicillin and trimethoprim, which presented moderate risks, and rifampicin and levofloxacin, which presented high risks. The RDR provides an efficient means to benchmark multiple antibiotics and treatment regimes in the initial phase of a risk assessment with regards to their potential to develop resistance in different environmental compartments, and can be used to derive resistance threshold concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Detection of molecular changes induced by antibiotics in Escherichia coli using vibrational spectroscopy

NASA Astrophysics Data System (ADS)

Xuan Nguyen, N. T.; Sarter, Samira; Hai Nguyen, N.; Daniel, Philippe

2017-08-01

This study aimed to test Raman (400-1800 cm- 1) and Infra-red (1900-500 cm- 1) spectroscopies followed by statistical analysis (principal component analysis) to detect molecular changes induced by antibiotics (ampicillin, cefotaxime - cell wall synthesis inhibitors, tetracycline - protein synthesis inhibitor, ciprofloxacin - DNA synthesis inhibitor) against Escherichia coli TOP10. In case of ampicillin and cefotaxime, a decrease in protein bands in both Raman (1240, 1660 cm- 1), and IR spectra (1230, 1530, 1630 cm- 1), and an increase in carbohydrate bands (1150, 1020 cm- 1) in IR spectra were observed. Tetracycline addition caused an increase in nucleic acid bands (775, 1478, 1578 cm- 1), a sharp decrease in phenylalanine (995 cm- 1) in Raman spectra and the amide I and amide II bands (1630, 1530 cm- 1) in IR spectra, an increase in DNA in both Raman (1083 cm- 1) and IR spectra (1080 cm- 1). Regarding ciprofloxacin, an increase in nucleic acids (775, 1478, 1578 cm- 1) in Raman spectra and in protein bands (1230, 1520, 1630 cm- 1), in DNA (1080 cm- 1) in IR spectra were detected. Clear discrimination of antibiotic-treated samples compared to the control was recorded, showing that Raman and IR spectroscopies, coupled to principal component analysis for data, could be used to detect molecular modifications in bacteria exposed to different classes of antibiotics. These findings contribute to the understanding of the mechanisms of action of antibiotics in bacteria.

Efflux pump-deficient mutants as a platform to search for microbes that produce antibiotics.

PubMed

Molina-Santiago, Carlos; Udaondo, Zulema; Daddaoua, Abdelali; Roca, Amalia; Martín, Jesús; Pérez-Victoria, Ignacio; Reyes, Fernando; Ramos, Juan-Luis

2015-07-01

Pseudomonas putida DOT-T1E-18 is a strain deficient in the major antibiotic efflux pump (TtgABC) that exhibits an overall increased susceptibility to a wide range of drugs when compared with the wild-type strain. We used this strain as a platform to search for microbes able to produce antibiotics that inhibit growth. A collection of 2400 isolates from soil, sediments and water was generated and a drop assay developed to identify, via growth inhibition halos, strains that prevent the growth of DOT-T1E-18 on solid Luria-Bertani plates. In this study, 35 different isolates that produced known and unknown antibiotics were identified. The most potent inhibitor of DOT-T1E-18 growth was an isolate named 250J that, through multi-locus sequence analysis, was identified as a Pseudomonas sp. strain. Culture supernatants of 250J contain four different xantholysins that prevent growth of Gram-positive bacteria, Gram-negative and fungi. Two of the xantholysins were produced in higher concentrations and purified. Xantholysin A was effective against Bacillus, Lysinibacillus and Rhodococcus strains, and the effect against these microbes was enhanced when used in combination with other antibiotics such as ampicillin, gentamicin and kanamycin. Xantholysin C was also efficient against Gram-positive bacteria and showed an interesting antimicrobial effect against Pseudomonas strains, and a synergistic inhibitory effect with ampicillin, chloramphenicol and gentamicin. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Incidence and transferability of antibiotic resistance in the enteric bacteria isolated from hospital wastewater

PubMed Central

Alam, Mohammad Zubair; Aqil, Farrukh; Ahmad, Iqbal; Ahmad, Shamim

2013-01-01

This study reports the occurrence of antibiotic resistance and production of β-lactamases including extended spectrum beta-lactamases (ESβL) in enteric bacteria isolated from hospital wastewater. Among sixty-nine isolates, tested for antibiotic sensitivity, 73.9% strains were resistant to ampicillin followed by nalidixic acid (72.5%), penicillin (63.8%), co-trimoxazole (55.1%), norfloxacin (53.6%), methicillin (52.7%), cefuroxime (39.1%), cefotaxime (23.2%) and cefixime (20.3%). Resistance to streptomycin, chloramphenicol, nitrofurantoin, tetracycline, and doxycycline was recorded in less than 13% of the strains. The minimum inhibitory concentration (MIC) showed a high level of resistance (800–1600 μg/mL) to one or more antibiotics. Sixty three (91%) isolates produced β-lactamases as determined by rapid iodometric test. Multiple antibiotic resistances were noted in both among ESβL and non-ESβL producers. The β-lactamases hydrolyzed multiple substrates including penicillin (78.8% isolates), ampicillin (62.3%), cefodroxil (52.2%), cefotoxime (21.7%) and cefuroxime (18.8%). Fifteen isolates producing ESβLs were found multidrug resistant. Four ESβL producing isolates could transfer their R-plasmid to the recipient strain E. coli K-12 with conjugation frequency ranging from 7.0 × 10−3 to 8.8 × 10−4. The findings indicated that ESβL producing enteric bacteria are common in the waste water. Such isolates may disseminate the multiple antibiotic resistance traits among bacterial community through genetic exchange mechanisms and thus requires immediate attention. PMID:24516448

Evaluation of different conditions and culture media for the recovery of Aeromonas spp. from water and shellfish samples.

PubMed

Latif-Eugenín, F; Beaz-Hidalgo, R; Figueras, M J

2016-09-01

To perform a comparative study for determining the optimum culture method (direct plating or enrichment) and medium (ampicillin dextrin agar (ADA), starch ampicillin agar (SAA), bile salts irgasan brilliant green modified (BIBG-m)) for recovering Aeromonas species from water and shellfish samples. By direct culture, Aeromonas was detected in 65% (13/20) of the water samples and in 54·5% (6/11) of the shellfish samples. However, when a pre-enrichment step was included, the number of positive water samples increased to 75% (15/20) and the ones of shellfish to 90·1% (10/11). The enriched culture significantly favoured (P < 0·05) the isolation of Aeromonas allosaccharophila from water, Aeromonas salmonicida from shellfish and Aeromonas caviae from both types of samples. The most specific (P < 0·05) culture medium for detecting Aeromonas from water was ADA. However, no differences were observed in the case of shellfish samples (P > 0·05). Isolation of Aeromonas media from water was favoured (P < 0·05) in the ADA medium, while SAA enhanced (P < 0·05) the isolation of Aer. salmonicida from shellfish. The culture method and medium used influenced the recovery of some Aeromonas species from water and shellfish samples. This fact should be considered in future prevalence studies to avoid overestimating the above mentioned Aeromonas species. © 2016 The Society for Applied Microbiology.

Validation of the BetaStar® Advanced for Beta-lactams Test Kit for the Screening of Bulk Tank and Tanker Truck Milks for the Presence of Beta-lactam Drug Residues.

PubMed

Denhartigh, Andrew; Reynolds, Lindsay; Palmer, Katherine; Klein, Frank; Rice, Jennifer; Rejman, John J

2018-05-18

A validation study was conducted for an immunochromatographic method (BetaStar ® Advanced for Beta-lactams) for the detection of beta-lactam residues in raw, commingled bovine milk. The assay detected amoxicillin, ampicillin, cloxacillin, penicillin, cephapirin, and ceftiofur below the U.S. Food and Drug Administration tolerance levels but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments. The results of internal and independent laboratory dose-response studies employing spiked samples were in agreement. The test detected all six drugs at the approximate 90/95% sensitivity levels in milk from cows treated with each drug. Selectivity of the assay was 100%, as no false-positive results were obtained in testing 1148 control milk samples. Testing the estimated 90/95% sensitivity level for amoxicillin (8.5 ppb), ampicillin (6.9 ppb), cloxacillin (8.9 ppb), penicillin (4.2 ppb), and cephapirin (17.6 ppb), and at 100 ppb for each antibiotic, resulted in 94-100% positive tests for each of the beta-lactam drugs. The results of ruggedness experiments established the operating parameter tolerances for the assay. Cross-reactivity testing established that the assay detects other certain beta-lactam drugs, but it does not cross-react with any of 30 drugs belonging to seven different drug classes. Abnormally high bacterial or somatic cell counts in raw milk produced no assay interference.

Rate of preterm births in pregnant women with common lower genital tract infection: a population-based study based on the clinical practice.

PubMed

Bánhidy, Ferenc; Acs, Nándor; Puho, Erzsébet H; Czeizel, Andrew E

2009-05-01

To estimate the rate of preterm births in pregnant women with lower genital tract infection, i.e. vulvovaginitis-bacterial vaginosis and to check their prevention by drug treatments in the usual clinical practice. The rate of preterm birth of pregnant women with or without lower genital tract infection was evaluated in the population-based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities. Only prospectively and medically recorded diagnoses of vulvovaginitis-bacterial vaginosis were evaluated. Of 38,151 newborn infants, 2698 (7.1%) had mothers with vulvovaginitis-bacterial vaginosis diagnosed in early pregnancy and the rate of preterm births was 7.5% among them, while this figure was 9.3% in babies born to mothers without these recognized genital infections. After early diagnosis and treatment of vulvovaginitis-bacterial vaginosis, clotrimazole and ampicillin seemed to be most effective to reduce the preterm birth during the study period. However, the rate of preterm births was lower in babies born to mothers without recorded vulvovaginitis-bacterial vaginosis but treated by clotrimazole and ampicillin (7.2-7.8%) as well. The lower rate of preterm births in babies born to mothers with vulvovaginitis-bacterial vaginosis may be explained by their effective treatment. However, the high rate of preterm births in pregnant women without genital tract infection and antimicrobial treatment may be connected with asymptomatic or unrecognized symptomatic and untreated vaginal infections.

Combination Therapy Strategies Against Multiple-Resistant Streptococcus Suis.

PubMed

Yu, Yang; Fang, Jin-Tao; Zheng, Mei; Zhang, Qing; Walsh, Timothy R; Liao, Xiao-Ping; Sun, Jian; Liu, Ya-Hong

2018-01-01

Streptococcus suis is a major swine pathogen, an emerging zoonotic agent responsible for meningitis, endocarditis and septicaemia followed by deafness in humans. The development of antimicrobial resistance in S. suis increases the risk for therapeutic failure in both animals and humans. In this study, we report the synergism of combination therapy against multi-resistant S. suis isolates from swine. Twelve antibiotic profiles were determined against 11 S. suis strains. To investigate their synergistic/antagonistic activity, checkerboard assay was performed for all the possible combinations. In-vitro killing curves and in-vivo treatment trials were used to confirm the synergistic activity of special combinations against S. suis dominant clones. In this study, 11 S. suis isolates were highly resistant to erythromycin, clindamycin, trimethoprim/sulfamethoxazole, and tetracycline with ratios of 80-100%, and the resistance percentages to enrofloxacin, florfenicol, and spectinomycin were ~50%. The checkerboard data identified two combination regimens, ampicillin plus apramycin and tiamulin plus spectinomycin which gave the greatest level of synergism against the S. suis strains. In-vitro kill-curves showed a bacterial reduction of over 3-logCFU with the use of combination treatments, whilst the application of mono-therapies achieve less than a 2-logCFU cell killing. In-vivo models confirm that administration of these two combinations significantly reduced the number of bacterial cells after 24 h of treatment. In conclusions, the combinations of ampicillin plus apramycin and tiamulin plus spectinomycin showed the greatest synergism and may be potential strategies for treatment of multi-resistant S. suis in animal.

Indole-Induced Activities of β-Lactamase and Efflux Pump Confer Ampicillin Resistance in Pseudomonas putida KT2440

PubMed Central

Kim, Jisun; Shin, Bora; Park, Chulwoo; Park, Woojun

2017-01-01

Indole, which is widespread in microbial communities, has received attention because of its effects on bacterial physiology. Pseudomonas putida and Pseudomonas aeruginosa can acquire ampicillin (Amp) resistance during growth on indole-Amp agar. Transcriptome, mutant, and inhibitor studies have suggested that Amp resistance induced by indole can be attributed to increased gene expression of ttgAB encoding two genes of RND-type multidrug efflux operons and an ampC encoding β-lactamase. Expression, enzyme activities, and mutational analyses indicated that AmpC β-lactamase is important for acquiring Amp resistance of P. putida in the presence of indole. Here, we show, for the first time, that volatile indole increased Amp-resistant cells. Consistent with results of the volatile indole assay, a low concentration of indole in liquid culture promoted growth initially, but led to mutagenesis after indole was depleted, which could not be observed at high indole concentrations. Interestingly, ttgAB and ampC gene expression levels correlate with the concentration of indole, which might explain the low number of Amp-mutated cells in high indole concentrations. The expression levels of genes involved in mutagenesis, namely rpoS, recA, and mutS, were also modulated by indole. Our data indicates that indole reduces Amp-induced heterogeneity by promoting expression of TtgABC or MexAB-OprM efflux pumps and the indole-induced β-lactamase in P. putida and P. aeruginosa. PMID:28352264

Performances of antibiotic screening tests in determining the persistence of penicillin residues in ewe's milk.

PubMed

Berruga, M I; Yamaki, M; Althaus, R L; Molina, M P; Molina, A

2003-11-01

Milk collected at 12-h intervals throughout 6 days from three groups of Manchega ewes (n = 12 per group), treated intramuscularly with beta-lactams (benzyl penicillin procaine, ampicillin, and amoxicillin, respectively), was evaluated for antibiotic residue persistence with four microbial inhibitor tests (BRT MRL, CH ATK P&S, Delvotest SP, and Eclipse 100ov) and one enzymatic test (Penzym 100). Antibiotic depletion time was established using a logistic regression model. A clear effect (P < 0.0001) of milking order on the response of all tests was observed with the three antibiotics, but no significant effects were found for milk yield. Except with Eclipse 100ov, positive tests were observed after the recommended withdrawal period of benzyl penicillin procaine (five milkings) from 2% (Delvotest SP) to 11% (CH ATK P&S). There were almost no positive responses beyond the withdrawal period (six milkings) of ampicillin, except for the Penzym 100 test (7%). Residues of amoxicillin were found to persist beyond the six milkings established as the withdrawal period, from 2.8% (Eclipse 100ov) to 72.4% (CH ATK P&S) of positive cases. Higher frequencies of doubtful cases were found with BRT MRL and Delvotest SP assays with the three beta-lactams. Positive and doubtful results could be obtained when milk samples from individual ewes were analyzed using BRT MRL, CH ATK P&S, Delvotest SP, and Penzym 100 tests, even if farmers follow the antibiotic withdrawal periods.

Prevalence and antimicrobial sensitivity pattern of urinary tract infection among children with cerebral palsy, Moshi, Tanzania

PubMed Central

Ryakitimbo, Amon; Philemon, Rune; Mazuguni, Festo; Msuya, Levina

2018-01-01

Background Urinary tract infection (UTI) in children with cerebral palsy (CP) is a challenging yet common clinical condition. Children with CP bare the greatest risk of contracting UTI because of their difficulties in neuromotor control which lead to delay of bladder control, causing incomplete bladder emptying and urine retention. Method This was an analytical cross-sectional study that was conducted from September 2016 to March 2017 at Comprehensive Community Based Rehabilitation in Tanzania – Moshi and Kilimanjaro Christian Medical Centre Neurological Pediatrics Outpatient Clinic. All children who met the inclusion criteria were studied. Urine samples were collected at one point by catheterization, and urine dipstick and urine culture were done. Data were analyzed using SPSS version 20. Results A total of 99 children were enrolled in the study. The median age was 4 years (3–8 years); 53.5% were aged between 2 and 4 years. More than half were male. UTI was detected in 13.1% (n=13) of the children. Five causative agents of UTI were isolated, namely Escherichia coli, Proteus mirabilis, Klebsiella pneumonia, Staphylococcus aureus, and Enterococcus faecalis. The two most common organisms, E. coli and P. mirabilis, both had low sensitivity to ampicillin and co-trimoxazole while they were sensitive to ciprofloxacin and ceftriaxone. Conclusion UTI is a common finding among children with CP. E. coli and P. mirabilis are the commonest causative agents and are sensitive to ciprofloxacin and ceftriaxone but have low sensitivity to ampicillin and co-trimoxazole. PMID:29774893

Diarrheagenic Escherichia coli strains recovered from urban pigeons (Columba livia) in Brazil and their antimicrobial susceptibility patterns.

PubMed

Silva, Vânia L; Nicoli, Jacques R; Nascimento, Thiago C; Diniz, Cláudio G

2009-09-01

Urban pigeons (Columba livia) come into close contact with humans and animals, and may contribute to the spread of infectious agents. These may include human pathogens such as diarrheagenic Escherichia coli strains, which are able to survive in pigeon feces, thus creating potential for human exposure and infection. Our objectives were to determine the occurrence of diarrheagenic E. coli strains in fresh feces from urban pigeons and their drug susceptibility patterns. E. coli strains were isolated from 100 fresh feces samples and presumptive phenotypic species identification was carried out, confirmed by amplification of specific 16S ribosomal RNA encoding DNA. Multiplex PCR was performed to characterize pathogenic strains. Drug susceptibility patterns were determined by the agar dilution method. Enteroinvasive E. coli, Shiga toxin-producing E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli were detected at an overall rate of 12.1%. Among the isolated E. coli strains, 62.1% were susceptible to all tested drugs, whereas 37.9% were resistant to at least one of the antimicrobials tested. Amikacin was the less effective drug (36.8% resistance), followed by ampicillin (7.8%). No resistance was detected to gentamicin, ceftriaxone, and ceftazidime and almost all the isolates were susceptible to ampicillin-sulbactam (98.4%), levofloxacin (97.8%), and trimethoprim-sulfamethoxazole (96.1%). Since these pigeons may harbor multidrug-resistant pathogens, their presence in an urban environment could be an important component of infection spread, with impact on public health.

Frequency of resistance in obligate anaerobic bacteria isolated from dogs, cats, and horses to antimicrobial agents.

PubMed

Lawhon, S D; Taylor, A; Fajt, V R

2013-11-01

Clinical specimens from dogs, cats, and horses were examined for the presence of obligate anaerobic bacteria. Of 4,018 specimens cultured, 368 yielded 606 isolates of obligate anaerobic bacteria (248 from dogs, 50 from cats, and 308 from horses). There were 100 specimens from 94 animals from which only anaerobes were isolated (25 dogs, 8 cats, and 61 horses). The most common sites tested were abdominal fluid (dogs and cats) and intestinal contents (horses). The most common microorganism isolated from dogs, cats, and horses was Clostridium perfringens (75, 13, and101 isolates, respectively). The MICs of amoxicillin with clavulanate, ampicillin, chloramphenicol, metronidazole, and penicillin were determined using a gradient endpoint method for anaerobes. Isolates collected at necropsy were not tested for antimicrobial susceptibility unless so requested by the clinician. There were 1/145 isolates tested that were resistant to amoxicillin-clavulanate (resistance breakpoint ≥ 16/8 μg/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ≥ 2 μg/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ≥ 32 μg/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ≥ 8 μg/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ≥ 32 μg/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ≥ 2 μg/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugs in vitro.

Heavy-Metal and Antibiotic Resistance in the Bacterial Flora of Sediments of New York Bight

PubMed Central

Timoney, J. F.; Port, Jennifer; Giles, Janis; Spanier, J.

1978-01-01

The New York Bight extends seaward some 80 to 100 miles (ca. 129 to 161 km) from the Long Island and New Jersey shorelines to the edge of the continental shelf. Over 14 × 106 m3 of sewage sludge, dredge spoils, acid wastes, and cellar dirt are discharged into this area each year. Large populations of Bacillus sp. resistant to 20 μg of mercury per ml were observed in Bight sediments contaminated by these wastes. Resistant Bacillus populations were much greater in sediments containing high concentrations of Hg and other heavy metals than in sediments from areas further offshore where dumping has never been practiced and where heavy-metal concentrations were found to be low. Ampicillin resistance due mainly to β-lactamase production was significantly (P < 0.001) more frequent in Bacillus strains from sediments near the sewage sludge dump site than in similar Bacillus populations from control sediments. Bacillus strains with combined ampicillin and Hg resistances were almost six times as frequent at the sludge dump site as in control sediments. This observation suggests that genes for Hg resistance and β-lactamase production are simultaneously selected for in Bacillus and that heavy-metal contamination of an ecosystem can result in a selection pressure for antibiotic resistance in bacteria in that system. Also, Hg resistance was frequently linked with other heavy-metal resistances and, in a substantial proportion of Bacillus strains, involved reduction to volatile metallic Hg (Hg°). PMID:727779

Novel everting urologic access sheath: potential advantages of decreased cellular advancement.

PubMed

Camargo, Affonso H L A; Rubenstein, Jonathan N; Sozen, Sinan; Ershoff, Brent D; Stoller, Marshall L

2006-02-01

Axial forces are imposed on the urothelium during advancement of instruments across the urinary tract, potentially transferring cellular debris, bacteria, or urothelial carcinoma from one anatomic location to another. A prototype access sheath (Cystoglide; Percutaneous Systems, Mountain View, CA) was created that everts and radially dilates but does not provide axial forces during deployment that can be used in a variety of anatomic systems. We created a urinary-tract model to evaluate the in-vitro advancement of cells to compare this technology with using instruments alone. Blocks of sterile agar were created with 17F tracts of three lengths (2.7, 5.5, and 11 cm) with 5 mL of Luria-Bertani broth/ampicillin solution in a well at the end. The tips of a Cystoglide sheath and a traditional urologic instrument of the same diameter were dipped into a suspension of ampicillin-resistant Escherichia coli and advanced through the tracts. After a 10-second exposure, 4 mL of broth was collected and cultured. Bacterial growth was compared by measuring the optical density (OD) of the broth at multiple time points. The mean overall OD of the broth was significantly lower (P < 0.001) in the novel-sheath cultures than with a traditional instrument for all advancements at all tract lengths. The Cystoglide sheath significantly reduces the advancement of cells within an artificial urinary tract compared with a non-everting instrument. Clinical studies are needed to assess the utility of this technology in vivo.

A synergistic effect of artocarpanone from Artocarpus heterophyllus L. (Moraceae) on the antibacterial activity of selected antibiotics and cell membrane permeability.

PubMed

Septama, Abdi Wira; Xiao, Jianbo; Panichayupakaranant, Pharkphoom

2017-01-01

Artocarpanone isolated from Artocarpus heterophyllus L. (Moraceae) exhibits antibacterial activity. The present study investigated synergistic activity between artocarpanone and tetracycline, ampicillin, and norfloxacin, respectively, against methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa , and Escherichia coli . A broth microdilution method was used for evaluating antibacterial susceptibility. Synergistic effects were identified using a checkerboard method, and a bacterial cell membrane disruption was investigated by assay of released 260 nm absorbing materials following bacteriolysis. Artocarpanone exhibited weak antibacterial activity against MRSA and P. aeruginosa with minimum inhibitory concentrations values of 125 and 500 μg/mL, respectively. However, the compound showed strong antibacterial activity against E. coli (7.8 μg/mL). The interaction between artocarpanone and all tested antibiotics revealed indifference and additive effects against P. aeruginosa and E. coli (fractional inhibitory concentration index [FICI] values of 0.75-1.25). The combination of artocarpanone (31.2 μg/mL) and norfloxacin (3.9 μg/mL) resulted in synergistic antibacterial activity against MRSA, with an FICI of 0.28, while the interaction between artocarpanone and tetracycline, and ampicillin showed an additive effect, with an FICI value of 0.5. A time-kill assay also indicated that artocarpanone had a synergistic effect on the antibacterial activity of norfloxacin. In addition, the combination of artocarpanone and norfloxacin altered the membrane permeability of MRSA. These findings suggest that artocarpanone may be used to enhance the antibacterial activity of norfloxacin against MRSA.

A prospective study on evaluation of pathogenesis, biofilm formation, antibiotic susceptibility of microbial community in urinary catheter

NASA Astrophysics Data System (ADS)

Younis, Khansa Mohammed; Usup, Gires; Ahmad, Asmat

2015-09-01

This study is aimed to isolate, detect biofilm formation ability and antibiotic susceptibility of urinary catheter adherent microorganisms from elderly hospitalized patient at the Universiti Kebangsaan Malaysia Medical Center. Microorganisms were isolated from three samples of urinary catheters (UC) surface; one of the acute vascular rejection patient (UCB) and two from benign prostate hyperplasia patients (UCC and UCD). A total of 100 isolates was isolated with 35 from UCB, 38 (UCC) and 28 (UCD). Ninety six were identified as Gram-negative bacilli, one Gram-positive bacilli and three yeasts. Results of biofilm forming on sterile foley catheter showed that all the isolates can form biofilm at different degrees; strong biofilm forming: 32% from the 35 isolates (UCB), 25% out of 38 isolates (UCC), 26% out of 28 isolates (UCD). As for moderate biofilm forming; 3% from UCB, 10% from UCC and 2% from UCD. Weak biofilm forming in UCC (3%). The antibiotic susceptibility for (UCB) isolates showed highly resistant to ampicillin, novobiocin and penicillin 100 (%), kanamycin (97%), tetracycline (94%), chloramphenicol (91%), streptomycin (77%) and showed low level of resistance to gentamycin (17%), while all the isolates from (UCC-D) showed high resistant towards ampicillin and penicillin, novobiocin (94%), tetracycline (61%), streptomycin (53%), gentamycin (50%) and low level of resistance to kanamycin (48%), chloramphenicol (47%). The findings indicate that these isolates can spread within the community on urinary catheters surface and produce strong biofilm, therefore, monitoring antibiotic susceptibility of bacteria isolated in the aggregation is recommended.

Fluorescent ampicillin analogues as multifunctional disguising agents against opsonization

NASA Astrophysics Data System (ADS)

Kotagiri, Nalinikanth; Sakon, Joshua; Han, Haewook; Zharov, Vladimir P.; Kim, Jin-Woo

2016-06-01

Cancer nanomedicines are opening new paradigms in cancer management and recent research points to how they can vastly improve imaging and therapy through multimodality and multifunctionality. However, challenges to achieving optimal efficacy are manifold starting from processing materials and evaluating their intended effectiveness on biological tissue, to developing new strategies aimed at improving transport of these materials through the biological milieu to the target tissue. Here, we report a fluorescent derivative of a beta-lactam antibiotic, ampicillin (termed iAmp) and its multifunctional physicobiochemical characteristics and potential as a biocompatible shielding agent and an effective dispersant. Carbon nanotubes (CNTs) were chosen to demonstrate the efficacy of iAmp. CNTs are known for their versatility and have been used extensively for cancer theranostics as photothermal and photoacoustic agents, but have limited solubility in water and biocompatibility. Traditional dispersants are associated with imaging artifacts and are not fully biocompatible. The chemical structure of iAmp is consistent with a deamination product of ampicillin. Although the four-membered lactam ring is intact, it does not retain the antibiotic properties. The iAmp is an effective dispersant and simultaneously serves as a fluorescent label for single-walled CNTs (SWNTs) with minimal photobleaching. The iAmp also enables bioconjugation of SWNTs to bio-ligands such as antibodies through functional carboxyl groups. Viability tests show that iAmp-coated SWNTs have minimal toxicity. Bio-stability tests under physiological conditions reveal that iAmp coating not only remains stable in a biologically relevant environment with high protein and salt concentrations, but also renders SWNTs transparent against nonspecific protein adsorption, also known as protein corona. Mammalian tissue culture studies with macrophages and opsonins validate that iAmp coating affords immunological resistance to SWNTs. Furthermore, iAmp coating offers protection to SWNTs against their nonspecific adsorption across disparate cell types, which has precluded a targeted strategy, and enables selective molecular targeting. The iAmp can therefore be used as an efficient dispersant, a photostable fluorescent agent, and a biocompatible disguising agent, alleviating CNTs' drawbacks and rendering them suitable for nanotheranostic and drug delivery applications.Cancer nanomedicines are opening new paradigms in cancer management and recent research points to how they can vastly improve imaging and therapy through multimodality and multifunctionality. However, challenges to achieving optimal efficacy are manifold starting from processing materials and evaluating their intended effectiveness on biological tissue, to developing new strategies aimed at improving transport of these materials through the biological milieu to the target tissue. Here, we report a fluorescent derivative of a beta-lactam antibiotic, ampicillin (termed iAmp) and its multifunctional physicobiochemical characteristics and potential as a biocompatible shielding agent and an effective dispersant. Carbon nanotubes (CNTs) were chosen to demonstrate the efficacy of iAmp. CNTs are known for their versatility and have been used extensively for cancer theranostics as photothermal and photoacoustic agents, but have limited solubility in water and biocompatibility. Traditional dispersants are associated with imaging artifacts and are not fully biocompatible. The chemical structure of iAmp is consistent with a deamination product of ampicillin. Although the four-membered lactam ring is intact, it does not retain the antibiotic properties. The iAmp is an effective dispersant and simultaneously serves as a fluorescent label for single-walled CNTs (SWNTs) with minimal photobleaching. The iAmp also enables bioconjugation of SWNTs to bio-ligands such as antibodies through functional carboxyl groups. Viability tests show that iAmp-coated SWNTs have minimal toxicity. Bio-stability tests under physiological conditions reveal that iAmp coating not only remains stable in a biologically relevant environment with high protein and salt concentrations, but also renders SWNTs transparent against nonspecific protein adsorption, also known as protein corona. Mammalian tissue culture studies with macrophages and opsonins validate that iAmp coating affords immunological resistance to SWNTs. Furthermore, iAmp coating offers protection to SWNTs against their nonspecific adsorption across disparate cell types, which has precluded a targeted strategy, and enables selective molecular targeting. The iAmp can therefore be used as an efficient dispersant, a photostable fluorescent agent, and a biocompatible disguising agent, alleviating CNTs' drawbacks and rendering them suitable for nanotheranostic and drug delivery applications. Electronic supplementary information (ESI) available: Details of quantum yield estimation and physicobiochemical analyses to assess the mechanism of iAmp synthesis and its chemical structure as well as the cytotoxicity and bio-stability of iAmp and iAmp-SWNT hybrids. See DOI: 10.1039/c5nr08686h

In Vitro Sensitivity and Resistance of 46 Leptospira Strains Isolated from Rats in the Philippines to 14 Antimicrobial Agents▿ †

PubMed Central

Chakraborty, Antara; Miyahara, Satoshi; Villanueva, Sharon Y. A. M.; Gloriani, Nina G.; Yoshida, Shin-ichi

2010-01-01

The in vitro susceptibilities of 46 Leptospira isolates from rats to 14 antimicrobial agents were tested. All of the strains were found to be sensitive to ampicillin, cefotaxime, ciprofloxacin, norfloxacin, doxycycline, erythromycin, and streptomycin. In contrast, the tested isolates showed resistance to amphotericin B, 5-fluorouracil, fosfomycin, trimethoprim, sulfamethoxazole, neomycin, and vancomycin. These findings will help in selecting effective and ineffective antimicrobials for treatment of leptospirosis and for the development of new selective media, respectively. PMID:20855741

DNA transformation via local heat shock

NASA Astrophysics Data System (ADS)

Li, Sha; Meadow Anderson, L.; Yang, Jui-Ming; Lin, Liwei; Yang, Haw

2007-07-01

This work describes transformation of foreign DNA into bacterial host cells by local heat shock using a microfluidic system with on-chip, built-in platinum heaters. Plasmid DNA encoding ampicillin resistance and a fluorescent protein can be effectively transformed into the DH5α chemically competent E. coli using this device. Results further demonstrate that only one-thousandth of volume is required to obtain transformation efficiencies as good as or better than conventional practices. As such, this work complements other lab-on-a-chip technologies for potential gene cloning/therapy and protein expression applications.

Enterococcus faecalis endocarditis following percutaneous manipulation of a biliary tract calculus and ERCP

PubMed Central

Ronald, Allan R; Pattullo, Andrew LS

1990-01-01

A case of Enterococcus faecalis endocarditis followed endoscopic retrograde cholangiopancreatography and percutaneous extraction of a biliary calculus is reported. The most likely cause of endocarditis, though unproven, is the latter procedure, as the bile is often infected during biliary tract obstruction, and bacteremia is frequent during percutaneous manipulations. Initial therapy with vancomycin was unsuccessful in clearing the bacteremia, possibly due to vancomycin tolerance of the isolate and lack of an aminoglycoside in the initial regimen. Cure was obtained when therapy with ampicillin and gentamicin was undertaken. PMID:22553458

Dimethyl Sulfoxide Protects Escherichia coli from Rapid Antimicrobial-Mediated Killing.

PubMed

Mi, Hongfei; Wang, Dai; Xue, Yunxin; Zhang, Zhi; Niu, Jianjun; Hong, Yuzhi; Drlica, Karl; Zhao, Xilin

2016-08-01

The contribution of reactive oxygen species (ROS) to antimicrobial lethality was examined by treating Escherichia coli with dimethyl sulfoxide (DMSO), an antioxidant solvent frequently used in antimicrobial studies. DMSO inhibited killing by ampicillin, kanamycin, and two quinolones and had little effect on MICs. DMSO-mediated protection correlated with decreased ROS accumulation and provided evidence for ROS-mediated programmed cell death. These data support the contribution of ROS to antimicrobial lethality and suggest caution when using DMSO-dissolved antimicrobials for short-time killing assays. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Occurrence and properties of composite transposon Tn2672: evolution of multiple drug resistance transposons.

PubMed Central

Hänni, C; Meyer, J; Iida, S; Arber, W

1982-01-01

We found Tn2671 (the 23-kb long IS1-flanked r-determinant of NR1-Basel) inserted into the ampicillin resistance gene bla of the Tn3-related transposon Tn902. The resulting 28-kilobase-long composite transposon Tn2672 (= Tn902 bla::Tn2671) is stable, and it translocates as a unit into various loci including IS1 of the resistance transfer factor of R100-1. These results are discussed with respect to the evolution of R plasmids providing multiple drug resistance. Images PMID:6281241

CARB-17 Family of β-Lactamases Mediates Intrinsic Resistance to Penicillins in Vibrio parahaemolyticus

PubMed Central

Chiou, Jiachi; Li, Ruichao

2015-01-01

Vibrio parahaemolyticus is commonly resistant to ampicillin, yet the mechanisms underlying this phenomenon are not clear. In this study, a novel class A carbenicillin-hydrolyzing β-lactamase (CARB) family of β-lactamases, blaCARB-17, was identified and found to be responsible for the intrinsic penicillin resistance in V. parahaemolyticus. Importantly, blaCARB-17-like genes were present in all 293 V. parahaemolyticus genome sequences available in GenBank and detectable in all 91 V. parahaemolyticus food isolates, further confirming the intrinsic nature of this gene. PMID:25801555

Chryseomonas luteola from Bile Culture in an Adult Male with Severe Jaundice.

PubMed

De, Anuradha S; Salunke, Parul P; Parikh, Harshal R; Baveja, Sujata M

2010-01-01

A 60-year-old male was admitted in this hospital with severe jaundice, who had open cholecystectomy done 2 months ago. ERCP was performed and bile was sent for culture. It grew Chryseomonas luteola in pure culture. He underwent hepaticojejunostomy after 1 month. Total bilirubin improved gradually. His condition was stable on discharge. Prompt diagnosis of non-fermenters is required, as some of them are resistant to multiple antibiotics. Clinicians have to be made aware of the pathogenic role of C. luteola and its resistance to ampicillin and cephalosporins.

Determination of asymptomatic carrier rate of beta-haemolytic group B Streptococcus in vaginas of pregnant women in Ibadan, Nigeria.

PubMed

Olanisebe, S B; Adetosoye, A I

1986-04-01

Bacteriological studies of 500 vaginal swabs from pregnant women in second and third trimester from 4 government hospitals in Ibadan showed that 8 (1.6 per cent) were found to be culture-positive for Group B Streptococcus. Five (1.0 per cent) were found to harbour group D streptococci. All the 8 group B Streptococcus isolates were sensitive to erythromycin, methicillin, penicillin G, ampicillin and chloramphenicol in decreasing order. They were resistant to tetracycline, sulphafurazole and streptomycin.

Do Prostate Cancer Exosomes Generate a Field Effect Leading to Tumor Multifocality

DTIC Science & Technology

2016-04-01

ELEMENT NUMBER 6. AUTHOR(S) Marco Bisoffi 5d. PROJECT NUMBER 5e. TASK NUMBER E-Mail: bisoffi@chapman.edu 5f. WORK UNIT NUMBER 7... Sigma St. Louis MO. Plasmids were propagated in E. coli strain JM109 grown in LB broth containing 100ug/mL ampicillin and purified using spin column...buffer: 25 mM Tris, 8 mM MgCl2, 1 mM DTT, 15% glycerol, 1% TritonX-100, protease inhibitor cocktail ( Sigma St. Louis MO). Insoluble cell material was

Antibiotic treatment in childhood community-acquired pneumonia - clinical practice versus guidelines: results from two university hospitals.

PubMed

Man, Sorin Claudiu; Sas, Valentina; Schnell, Cristina; Florea, Camelia; Ţuţu, Adelina; Szilágyi, Ariana; Belenes, Sergiu; Hebriştean, Amalia; Bonaţ, Anca; Cladovan, Claudia; Aldea, Cornel

2018-01-01

Community-acquired pneumonia (CAP) is a both common and serious childhood infection. Antibiotic treatment guidelines help to reduce inadequate antibiotics prescriptions. We conducted a retrospective study at the Clinical Emergency Hospital for Children, 3rd Pediatric Clinic, Cluj-Napoca and Dr. Gavril Curteanu Clinical City Hospital, in Oradea. All patients discharged with a diagnosis of CAP between December 1, 2014 and February 28, 2015, were included in the study. There were 146 cases discharged with pneumonia in Cluj-Napoca center (mean age 4 years; range: 1 month - 16 years), and 212 cases in Oradea center (mean age 0.9 years; range: 2 weeks - 8 years). All cases were analyzed. The analysis made in Clinical Emergency Hospital for Children, 3rd Pediatric Clinic, Cluj-Napoca, showed that the antibiotics used in children hospitalized with community-acquired CAP are cefuroxime (43%), ceftriaxone (23%), macrolides (16%), ampicillin in association with an aminoglycoside (6%) and other antibiotics. The same antibiotics were used in Dr. Gavril Curteanu Clinical City Hospital of Oradea, where ampicillin in association with aminoglycoside was utilized in younger children (mean age 1.3 years), while ceftriaxone in older children (5.7 years) and children with high inflammation markers (ESR, CRP). From 11 pleurisy cases, 9 received cefuroxime or ceftriaxone. There was a wide variability in CAP antibiotic treatment across university hospitals, regarding antibiotic choice and dosing. Antibiotic selection was not always related to the clinical and laboratory characteristics of the patient. The national guideline was not followed, especially in children aged one to three months.

In vitro and in vivo activity of EDTA and antibacterial agents against the biofilm of mucoid Pseudomonas aeruginosa.

PubMed

Liu, Zhenqiu; Lin, Yaying; Lu, Qi; Li, Fang; Yu, Jialin; Wang, Zhengli; He, Yu; Song, Chao

2017-02-01

Refractory infection caused by bacterial biofilm is an important clinical problem. Pseudomonas aeruginosa is a common pathogen responsible for persistent and chronic biofilm infections. We aimed to explore the in vitro and in vivo activity of ethylenediamine tetraacetic acid (EDTA) in combination with antibacterial agents against mucoid P. aeruginosa biofilm. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration of ciprofloxacin, gentamicin, and ampicillin alone or with EDTA against P. aeruginosa were determined in vitro. Extracellular polysaccharides (EPS) and structural parameters of the biofilm were monitored. P. aeruginosa was aerosolized and delivered into the lungs of guinea pigs, which were treated with ciprofloxacin with or without EDTA. The colony-forming units (CFUs) of P. aeruginosa were determined from the lungs. EDTA reduced the MIC of ciprofloxacin and ampicillin by about 30-fold and that of gentamicin by twofold. EDTA reduced the biofilm EPS and the proportion of viable bacteria. The thickness, average diffusion distance, and textural entropy of EDTA-treated biofilm were significantly decreased. EDTA plus antibiotics reduced the colony counting from 10 7 to 10 3  CFU/mL. In vivo, EDTA plus ciprofloxacin had a significantly lower mean CFU/g of lung tissue (EDTA + ciprofloxacin 1.3 ± 0.19; EDTA 4.4 ± 0.57; ciprofloxacin 4.2 ± 0.47), and lung lesions were less severe compared with the single treatment groups. EDTA can destroy the biofilm structures of mucoid P. aeruginosa in vitro. Moreover, EDTA and ciprofloxacin had a significant bactericidal effect against biofilm in vivo.

High mortality among patients infected with hypervirulent antimicrobial-resistant capsular type K1 Klebsiella pneumoniae strains in Taiwan.

PubMed

Lin, Yi-Tsung; Cheng, Yi-Hsiang; Juan, Chih-Han; Wu, Ping-Feng; Huang, Yi-Wei; Chou, Sheng-Hua; Yang, Tsuey-Ching; Wang, Fu-Der

2018-06-12

Capsular type K1 Klebsiella pneumoniae, highly virulent strains which are common in Asian countries, can cause pyogenic infections. These hypervirulent strains are usually susceptible to most antimicrobials, except for ampicillin. Little is known regarding the clinical and molecular characteristics of antimicrobial-resistant K1 K. pneumoniae strains. This retrospective study evaluated patients infected with capsular type K1 K. pneumoniae strains in a Taiwanese medical centre between April 2013 and March 2016. Antimicrobial-resistant strains were defined based on non-susceptibility to antimicrobial agents except ampicillin. We compared the clinical outcome of patients infected with and without antimicrobial-resistant strains. The in vivo virulence, genetic relatedness, and resistance mechanisms of these hypervirulent antimicrobial-resistant strains were also investigated. A total of 182 capsular type K1 K. pneumoniae strains were identified, including 18 antimicrobial-resistant strains. The 28-day mortality rate among the 18 cases caused by antimicrobial-resistant strains was significantly higher than that among 164 cases caused by antimicrobial-sensitive strains (50% vs. 10.4%, p < 0.001). Infection with antimicrobial-resistant strain independently increased the 28-day mortality risk. Most antimicrobial -resistant strains were not clonally related, and they exhibited high in vivo virulence in a mouse lethality experiment. The major resistance mechanisms involved the presence of β-lactamases and the overexpression of efflux pumps. In conclusion, hypervirulent antimicrobial-resistant capsular type K1 K. pneumoniae strains can predispose to a fatal outcome. These strains may represent an emerging threat to public health in Taiwan. Copyright © 2018. Published by Elsevier B.V.

Study of antagonistic effects of Lactobacillus strains as probiotics on multi drug resistant (MDR) bacteria isolated from urinary tract infections (UTIs).

PubMed

Naderi, Atiyeh; Kasra-Kermanshahi, Roha; Gharavi, Sara; Imani Fooladi, Abbas Ali; Abdollahpour Alitappeh, Meghdad; Saffarian, Parvaneh

2014-03-01

Urinary tract infection (UTI) caused by bacteria is one of the most frequent infections in human population. Inappropriate use of antibiotics, often leads to appearance of drug resistance in bacteria. However, use of probiotic bacteria has been suggested as a partial replacement. This study was aimed to assess the antagonistic effects of Lactobacillus standard strains against bacteria isolated from UTI infections. Among 600 samples; those with ≥10,000 cfu/ml were selected as UTI positive samples. Enterococcus sp., Klebsiella pneumoniae, Enterobacter sp., and Escherichia coli were found the most prevalent UTI causative agents. All isolates were screened for multi drug resistance and subjected to the antimicrobial effects of three Lactobacillus strains by using microplate technique and the MICs amounts were determined. In order to verify the origin of antibiotic resistance of isolates, plasmid curing using ethidium bromide and acridine orange was carried out. No antagonistic activity in Lactobacilli suspension was detected against test on Enterococcus and Enterobacter strains and K. pneumoniae, which were resistant to most antibiotics. However, an inhibitory effect was observed for E. coli which were resistant to 8-9 antibiotics. In addition, L. casei was determined to be the most effective probiotic. RESULTS from replica plating suggested one of the plasmids could be related to the gene responsible for ampicillin resistance. Treatment of E. coli with probiotic suspension was not effective on inhibition of the plasmid carrying hypothetical ampicillin resistant gene. Moreover, the plasmid profiles obtained from probiotic-treated isolates were identical to untreated isolates.

Effect of farm type on within-herd Salmonella prevalence, serovar distribution, and antimicrobial resistance.

PubMed

Rasschaert, G; Michiels, J; Arijs, D; Wildemauwe, C; De Smet, S; Heyndrickx, M

2012-05-01

Salmonella represents a major challenge to the pig industry, as pork presents a risk for human salmonellosis. In this study, we have examined the effect of farm type on the prevalence of fattening pigs shedding Salmonella on 12 farms at risk for harboring Salmonella. On six open (grow-to-finish) and six closed (farrow-to-finish) farms, the prevalence of pigs shedding Salmonella was determined on two occasions approximately 2 months apart. The serovar, phage type, and antimicrobial resistance of the obtained Salmonella isolates were determined. On all farms, pigs shedding Salmonella were detected on at least one of the two sampling days. The mean within-herd prevalence was 7.8%. Closed farms were two times less likely to have pigs shedding Salmonella than open farms. On open farms, the odds of finding Salmonella shedding in pigs were 1.9 times higher when sampling was performed at slaughter age than when samples were taken halfway through the fattening period. Salmonella enterica serovar Typhimurium was the most predominant serotype, with a prevalence of 62 to 63% on both farm types. Of all the Salmonella Typhimurium isolates, 65% had the tetraresistant profile ASSuT (ampicillin, streptomycin, sulfonamide, and tetracycline) with or without additional resistance to trimethoprim-sulfonamide. Phage type DT120 seemed to be especially associated with this antimicrobial-resistant profile. The prevalence of Salmonella Typhimurium isolates showing resistance to ampicillin, streptomycin, tetracycline, sulfonamide, trimethoprim-sulfonamide, and lincomycin hydrochloride and spectinomycin sulfate tetrahydrate was significantly higher on open farms than on closed farms.

Phenotypic and molecular characterization of antimicrobial resistance in Proteus mirabilis isolates from dogs.

PubMed

Harada, Kazuki; Niina, Ayaka; Shimizu, Takae; Mukai, Yujiro; Kuwajima, Ken; Miyamoto, Tadashi; Kataoka, Yasushi

2014-11-01

Large-scale monitoring of resistance to 14 antimicrobial agents was performed using 103 Proteus mirabilis strains isolated from dogs in Japan. Resistant strains were analysed to identify their resistance mechanisms. Rates of resistance to chloramphenicol, streptomycin, enrofloxacin, trimethoprim/sulfamethoxazole, kanamycin, ampicillin, ciprofloxacin, cephalothin, gentamicin, cefoxitin and cefotaxime were 20.4, 15.5, 12.6, 10.7, 9.7, 8.7, 5.8, 2.9, 2.9, 1.9 and 1.9%, respectively. No resistance to ceftazidime, aztreonam or imipenem was found. Class 1 and 2 integrases were detected in 2.9 and 11.7% of isolates, respectively. Class 1 integrons contained aadB or aadB-catB-like-blaOXA10-aadA1, whereas those of class 2 contained sat-aadA1, dhfr1-sat-aadA1 or none of the anticipated resistance genes. Of five distinct plasmid-mediated quinolone-resistance (PMQR) genes, only qnrD gene was detected in 1.9% of isolates. Quinolone-resistance determining regions (QRDRs) of gyrA and parC from 13 enrofloxacin-intermediate and -resistant isolates were sequenced. Seven strains had double mutations and three had single mutations. Three of nine ampicillin-resistant isolates harboured AmpC-type β-lactamases (i.e. blaCMY-2, blaCMY-4 and blaDHA-1). These results suggest that canine Proteus mirabilis deserves continued surveillance as an important reservoir of antimicrobial resistance determinants. This is the first report, to our knowledge, describing integrons, PMQRs and QRDR mutations in Proteus mirabilis isolates from companion animals. © 2014 The Authors.

Antibiotic sensitivity pattern of causative organisms of neonatal septicemia in an urban hospital of Bangladesh.

PubMed

Monjur, Forhad; Rizwan, Farhana; Asaduzzaman, Muhammad; Nasrin, Nishat; Ghosh, Nobo Krishna; Apu, Apurba Sarker; Haque, Fazlul

2010-06-01

The information of the sensitivity pattern of the causative organisms is very important for effective control of septicemia in neonates. To determine the proportion and profile of pathogenic bacteria in the blood cultures of the neonates with clinically suspected septicemia and their susceptibility pattern to antimicrobial agents for developing a unified antibiotic treatment protocol. A cross-sectional retrospective study was conducted over a period of 3 year and 4 months (39 months). The study included 1000 patients admitted in the selected hospital in Bangladesh. Blood samples for culture were taken aseptically before starting antibiotic therapy. Microorganisms were isolated and identified by standard microbiological processes which include colony morphology, Gram stain, and biochemical profiles. Antimicrobial sensitivity patterns were performed by Kirby-Bauer's disc diffusion method against imipenem, ciprofloxacin, ceftazidime, chloramphenicol, netilmicin, gentamicin, ceftriaxone, aztreonam, cefotaxime, cephalexin, and ampicillin. Among the patients, 633 (63.3%) were males and 367 (36.7%) were females. Blood cultures were found positive in 194 (19.4%) neonates. The organisms isolated were Pseudomonas spp. (31.4%), Klebsiella pneumoniae (23.2%), Staphylococcus aureus (12.4%), Escherichia coli (7.2%), Acinatobactor (5.7%), Gram-negative Bacilli (4.1%), Flavobacterium spp. (3.6%), Serratia spp. (5.7%), Citrobacter fruendi (3.1%), Streptococcus species (2.6%), and Enterobacter spp. (1.0%). A majority of the bacterial isolates in neonatal sepsis were found sensitive to imipenem (91.8%) and ciprofloxacin (57.2%) and resistant to commonly used antibiotics, eg. ampicillin (96.4%) and cephalexin (89.2%). The problem can be mitigated by careful selection and prudent use of available antibiotics.

Efficacy of Telavancin Alone and in Combination with Ampicillin in a Rat Model of Enterococcus faecalis Endocarditis.

PubMed

Tran, Truc T; Tam, Vincent H; Murray, Barbara E; Arias, Cesar A; Singh, Kavindra V

2017-06-01

We first assessed telavancin (TLV) pharmacokinetics in rats after a single subcutaneous dose of 35 mg/kg of body weight. The pharmacokinetic data were used to predict a TLV dose that simulates human exposure, and the efficacy of TLV was then evaluated using a TLV dose of 21 mg/kg every 12 h against Enterococcus faecalis OG1RF (TLV MIC of 0.06 μg/ml) in a rat endocarditis model with an indwelling catheter. Therapy was given for 3 days with TLV, daptomycin (DAP), or ampicillin (AMP) monotherapy and with combinations of TLV plus AMP, AMP plus gentamicin (GEN), and AMP plus ceftriaxone (CRO); rats were sacrificed 24 h after the last dose. Antibiotics were given to simulate clinically relevant concentrations or as used in other studies. TLV treatment resulted in a significant decrease in bacterial burden (CFU per gram) in vegetations from 6.0 log 10 at time 0 to 3.1 log 10 after 3 days of therapy. Bacterial burdens in vegetations were also significantly lower in the TLV-treated rats than in the AMP ( P = 0.0009)- and AMP-plus-GEN ( P = 0.035)-treated rats but were not significantly different from that of the AMP-plus-CRO-treated rats. Bacterial burdens from vegetations in TLV monotherapy and TLV-plus-AMP-and-DAP groups were similar to each other ( P ≥ 0.05). Our data suggest that further study of TLV as a therapeutic alternative for deep-seated infections caused by vancomycin-susceptible E. faecalis is warranted. Copyright © 2017 American Society for Microbiology.

Multidrug-resistant enterococci in animal meat and faeces and co-transfer of resistance from an Enterococcus durans to a human Enterococcus faecium.

PubMed

Vignaroli, Carla; Zandri, Giada; Aquilanti, Lucia; Pasquaroli, Sonia; Biavasco, Francesca

2011-05-01

Forty-eight isolates resistant to at least two antibiotics were selected from 53 antibiotic-resistant enterococci from chicken and pig meat and faeces and analysed for specific resistance determinants. Of the 48 multidrug-resistant (MDR) strains, 31 were resistant to two antibiotics (29 to erythromycin and tetracycline, 1 to erythromycin and vancomycin, 1 to vancomycin and tetracycline), 14 to three (erythromycin, tetracycline and vancomycin or ampicillin) and 3 to four (erythromycin, vancomycin, ampicillin and gentamicin). erm(B), tet(M), vanA and aac (6')-Ie aph (2'')-Ia were the antibiotic resistance genes most frequently detected. All 48 MDR enterococci were susceptible to linezolid and daptomycin. Enterococcus faecalis (16), Enterococcus faecium (8), Enterococcus mundtii (2) and Enterococcus gallinarum (1) were identified in meat, and E. faecium (13) and Enterococcus durans (13) in faeces. Clonal spread was not detected, suggesting a large role of gene transfer in the dissemination of antibiotic resistance. Conjugative transfer of resistance genes was more successful when donors were enterococcal strains isolated from faeces; co-transfer of vanA and erm(B) to a human E. faecium occurred from both E. faecium and E. durans pig faecal strains. These data show that multidrug resistance can be found in food and animal species other than E. faecium and E. faecalis, and that these species can efficiently transfer antibiotic resistance to human strains in inter-specific matings. In particular, the occurrence of MDR E. durans in the animal reservoir could have a role in the emergence of human enterococcal infections difficult to eradicate with antibiotics.

Cognitive Impairment by Antibiotic-Induced Gut Dysbiosis: Analysis of Gut Microbiota-Brain Communication

PubMed Central

Fröhlich, Esther E.; Farzi, Aitak; Mayerhofer, Raphaela; Reichmann, Florian; Jačan, Angela; Wagner, Bernhard; Zinser, Erwin; Bordag, Natalie; Magnes, Christoph; Fröhlich, Eleonore; Kashofer, Karl; Gorkiewicz, Gregor; Holzer, Peter

2016-01-01

Emerging evidence indicates that disruption of the gut microbial community (dysbiosis) impairs mental health. Germ-free mice and antibiotic-induced gut dysbiosis are two approaches to establish causality in gut microbiota-brain relationships. However, both models have limitations, as germ-free mice display alterations in blood-brain barrier and brain ultrastructure and antibiotics may act directly on the brain. We hypothesized that the concerns related to antibiotic-induced gut dysbiosis can only adequately be addressed if the effect of intragastric treatment of adult mice with multiple antibiotics on (i) gut microbial community, (ii) metabolite profile in the colon, (iii) circulating metabolites, (iv) expression of neuronal signaling molecules in distinct brain areas and (v) cognitive behavior is systematically investigated. Of the antibiotics used (ampicillin, bacitracin, meropenem, neomycin, vancomycin), ampicillin had some oral bioavailability but did not enter the brain. 16S rDNA sequencing confirmed antibiotic-induced microbial community disruption, and metabolomics revealed that gut dysbiosis was associated with depletion of bacteria-derived metabolites in the colon and alterations of lipid species and converted microbe-derived molecules in the plasma. Importantly, novel object recognition, but not spatial, memory was impaired in antibiotic-treated mice. This cognitive deficit was associated with brain region-specific changes in the expression of cognition-relevant signaling molecules, notably brain-derived neurotrophic factor, N-methyl-D-aspartate receptor subunit 2B, serotonin transporter and neuropeptide Y system. We conclude that circulating metabolites and the cerebral neuropeptide Y system play an important role in the cognitive impairment and dysregulation of cerebral signaling molecules due to antibiotic-induced gut dysbiosis. PMID:26923630

Development of novel electrospun dual-drug fiber mats loaded with a combination of ampicillin and metronidazole.

PubMed

Schkarpetkin, Dennis; Reise, Markus; Wyrwa, Ralf; Völpel, Andrea; Berg, Albrecht; Schweder, Martina; Schnabelrauch, Matthias; Watts, David C; Sigusch, Bernd W

2016-08-01

Our study was performed with the aim of preparing electrospun polylactide fibers with a combination of ampicillin (AMP) and metronidazole (MNZ) and investigating their drug release behavior and the antibacterial effect on Aggregatibacter actinomycetemcomitans and other oral pathogens. AMP and MNZ were integrated as a combination in two separate fibers (dual fiber mats - DFW mix) of electrospun PLA fiber mats by means of multijet electrospinning and in a single fiber (single fiber mats - SFW mix). HPLC (high-performance liquid chromatography) was used to measure the released drug quantities. Agar diffusion tests were used to determine the antibacterial effect of the eluates on A. actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis and Enterococcus faecalis. The neutral red test was made to examine the cytocompatibility of the eluates with human gingival fibroblasts (hGFs). The release of the active agents varied with the antibiotic concentrations initially used in the fiber mats, but also with the distribution of the active agents in one or two fibers. Of the total quantity of MNZ (AMP), the SFW mix fiber mats released >60% (>70%) within a span of 5min, and 76% (71%) after 96h. With these drug concentrations released by the fiber mats (≥5m%), an antibacterial effect was achieved on A. actinomycetemcomitans and on all other species tested. Fiber mats and their eluates have no cytotoxic influence on human gingival fibroblasts (hGFs). Electrospun AMP/MNZ-loaded polymer fibers are a potential drug delivery system for use in periodontal and endodontic infections. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

First report on rapid screening of nanomaterial-based antimicrobial agents against β-lactamase resistance using pGLO plasmid transformed Escherichia coli HB 101 K-12

NASA Astrophysics Data System (ADS)

Raj, M. Alpha; Muralidhar, Y.; Sravanthi, M.; Prasad, T. N. V. K. V.; Nissipriya, M.; Reddy, P. Sirisha; Neelima, T. Shoba; Reddy, G. Dilip; Adilaxmamma, K.; Kumar, P. Anand; Krishna, T. Giridhara

2016-08-01

Combating antibiotic resistance requires discovery of novel antimicrobials effective against resistant bacteria. Herein, we present for the first time, pGLO plasmid transformed Escherichia coli HB 101 K 12 as novel model for screening of nanomaterial-based antimicrobial agents against β-lactamase resistance. E. coli HB 101 was transformed by pGLO plasmid in the presence of calcium chloride (50 mM; pH 6.1) aided by heat shock (0-42-0 °C). The transformed bacteria were grown on Luria-Bertani agar containing ampicillin (amp) and arabinose (ara). The transformed culture was able to grow in the presence of ampicillin and also exhibited fluorescence under UV light. Both untransformed and transformed bacteria were used for screening citrate-mediated nanosilver (CNS), aloin-mediated nanosilver (ANS), 11-α-keto-boswellic acid (AKBA)-mediated nanosilver (BNS); nanozinc oxide, nanomanganese oxide (NMO) and phytochemicals such as aloin and AKBA. Minimum inhibitory concentrations (MIC) were obtained by microplate method using ρ-iodo nitro tetrazolium indicator. All the compounds were effective against transformed bacteria except NMO and AKBA. Transformed bacteria exhibited reverse cross resistance against aloin. ANS showed the highest antibacterial activity with a MIC of 0.32 ppm followed by BNS (10.32 ppm), CNS (20.64 ppm) and NZO (34.83 ppm). Thus, pGLO plasmid can be used to induce resistance against β-lactam antibiotics and the model can be used for rapid screening of new antibacterial agents effective against resistant bacteria.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2012: General view of the pathogens' antibacterial susceptibility.

PubMed

Yanagihara, Katsunori; Watanabe, Akira; Aoki, Nobuki; Matsumoto, Tetsuya; Yoshida, Masaki; Sato, Junko; Wakamura, Tomotaro; Sunakawa, Keisuke; Kadota, Junichi; Kiyota, Hiroshi; Iwata, Satoshi; Kaku, Mitsuo; Hanaki, Hideaki; Ohsaki, Yoshinobu; Fujiuchi, Satoru; Takahashi, Manabu; Takeuchi, Kenichi; Takeda, Hiroaki; Ikeda, Hideki; Miki, Makoto; Nakanowatari, Susumu; Takahashi, Hiroshi; Utagawa, Mutsuko; Nishiya, Hajime; Kawakami, Sayoko; Morino, Eriko; Takasaki, Jin; Mezaki, Kazuhisa; Chonabayashi, Naohiko; Tanaka, Chie; Sugiura, Hideko; Goto, Hajime; Saraya, Takeshi; Kurai, Daisuke; Katono, Yasuhiro; Inose, Rika; Niki, Yoshihito; Takuma, Takahiro; Kudo, Makoto; Ehara, Shigeru; Sato, Yoshimi; Tsukada, Hiroki; Watabe, Nobuei; Honma, Yasuo; Mikamo, Hiroshige; Yamagishi, Yuka; Nakamura, Atsushi; Ohashi, Minoru; Seki, Masafumi; Hamaguchi, Shigeto; Toyokawa, Masahiro; Fujikawa, Yasunori; Mitsuno, Noriko; Ukimura, Akira; Miyara, Takayuki; Nakamura, Takahito; Mikasa, Keiichi; Kasahara, Kei; Ui, Koji; Fukuda, Saori; Nakamura, Akihiro; Morimura, Mika; Yamashita, Mikio; Takesue, Yoshio; Wada, Yasunao; Sugimoto, Keisuke; Kusano, Nobuchika; Nose, Motoko; Mihara, Eiichirou; Kuwabara, Masao; Doi, Masao; Watanabe, Yaeko; Tokuyasu, Hirokazu; Hino, Satoshi; Negayama, Kiyoshi; Mukae, Hiroshi; Kawanami, Toshinori; Ota, Toshiyuki; Fujita, Masaki; Honda, Junichi; Hiramatsu, Kazufumi; Aoki, Yosuke; Fukuoka, Mami; Magarifuchi, Hiroki; Nagasawa, Zenzo; Kaku, Norihito; Fujita, Jiro; Higa, Futoshi; Tateyama, Masao

2017-09-01

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, Japanese association for infectious diseases and Japanese society for Clinical Microbiology in 2012. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January and December in 2012 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standard Institutes. Susceptibility testing was evaluated in 1236 strains (232 Staphylococcus aureus, 225 Streptococcus pneumoniae, 16 Streptococcus pyogenes, 231 Haemophilus influenzae, 147 Moraxella catarrhalis, 167 Klebsiella pneumoniae and 218 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 51.3%, and those of penicillin-intermediate S. pneumoniae was 0.4%. Among H. influenzae, 5.6% of them were found to be β-lactamase-producing ampicillin-resistant strains, and 37.2% to be β-lactamase-non-producing ampicillin-resistant strains. Extended spectrum β-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo β-lactamase were 4.2% and 3.2%, respectively. Continuous national surveillance is important to determine the actual situation of the resistance shown by bacterial respiratory pathogens to antimicrobial agents. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Antibiotic Treatment of Experimental Pneumonic Plague in Mice

PubMed Central

Byrne, William R.; Welkos, Susan L.; Pitt, M. Louise; Davis, Kelly J.; Brueckner, Ralf P.; Ezzell, John W.; Nelson, Gene O.; Vaccaro, Joseph R.; Battersby, Luann C.; Friedlander, Arthur M.

1998-01-01

A mouse model was developed to evaluate the efficacy of antibiotic treatment of pneumonic plague; streptomycin was compared to antibiotics with which there is little or no clinical experience. Infection was induced by inhalation of aerosolized Yersinia pestis organisms. Antibiotics were administered by intraperitoneal injection every 6 hours for 5 days, at doses that produced levels of drug in serum comparable to those observed in humans treated for other serious infections. These studies compared in vitro to in vivo activity and evaluated the efficacy of antibiotics started at different times after exposure. Early treatment (started 24 h after challenge, when 0 of 10 mice tested had positive blood cultures) with netilmicin, ciprofloxacin, ofloxacin, ceftriaxone, ceftazidime, aztreonam, ampicillin, and rifampin (but not cefazolin, cefotetan, or ceftizoxime) demonstrated efficacy comparable to streptomycin. Late treatment (started 42 h after exposure, when five of five mice tested had positive blood cultures) with netilmicin, ciprofloxacin, ofloxacin, and a high dose (20 mg/kg of body weight every 6 h) of gentamicin produced survival rates comparable to that with streptomycin, while all of the beta-lactam antibiotics (cefazolin, cefotetan, ceftriaxone, ceftazidime, aztreonam, and ampicillin) and rifampin were significantly inferior to streptomycin. In fact, all groups of mice treated late with beta-lactam antibiotics experienced accelerated mortality rates compared to normal-saline-treated control mice. These studies indicate that netilmicin, gentamicin, ciprofloxacin, and ofloxacin may be alternatives for the treatment of pneumonic plague in humans. However, the beta-lactam antibiotics are not recommended, based upon poor efficacy in this mouse model of pneumonic plague, particularly when pneumonic plague may be associated with bacteremia. PMID:9517950

Distribution, Detection of Enterotoxigenic Strains and Antimicrobial Drug Susceptibility Patterns of Bacteroides Fragilis Group in Diarrheic and Non-Diarrheic Feces from Brazilian Infants

PubMed Central

Ferreira, Débora Paula; Silva, Vânia Lúcia; Guimarães, Danielle Aparecida; Coelho, Cíntia Marques; Zauli, Danielle Alves Gomes; Farias, Luiz Macêdo; Carvalho, Maria Auxiliadora Roque; Diniz, Claudio Galuppo

2010-01-01

Despite the importance of gastrointestinal diseases and their global distribution, affecting millions of individuals around the world, the role and antimicrobial susceptibility patterns of anaerobic bacteria such as those in the Bacteroides fragilis group (BFG) are still unclear in young children. This study investigated the occurrence and distribution of species in the BFG and enterotoxigenic strains in the fecal microbiota of children and their antimicrobial susceptibility patterns. Diarrheic (n=110) and non-diarrheic (n=65) fecal samples from children aged 0–5 years old were evaluated. BFG strains were isolated and identified by conventional biochemical, physiological and molecular approaches. Alternatively, bacteria and enterotoxigenic strains were detected directly from feces by molecular biology. Antimicrobial drug susceptibility patterns were determined by the agar dilution method according to the guidelines for isolated bacteria. BFG was detected in 64.3% of the fecal samples (55% diarrheic and 80.4% non-diarrheic), and 4.6% were enterotoxigenic. Antimicrobial resistance was observed against ampicillin, ampicillin/sulbactam, piperacillin/tazobactam, meropenem, ceftriaxone, clindamycin and chloramphenicol. The data show that these bacteria are prevalent in fecal microbiota at higher levels in healthy children. The molecular methodology was more effective in identifying the B. fragilis group when compared to the biochemical and physiological techniques. The observation of high resistance levels stimulates thoughts about the indiscriminate use of antimicrobial drugs in early infancy. Further quantitative studies are needed to gain a better understanding of the role of these bacteria in acute diarrhea in children. PMID:24031535

Direct detection of the multidrug resistance genome of Haemophilus influenzae in cerebrospinal fluid of children: implications for treatment of meningitis.

PubMed

Saha, Samir K; Darmstadt, Gary L; Baqui, Abdullah H; Islam, Nurul; Qazi, Shamim; Islam, Maksuda; El Arifeen, Shams; Santosham, Mathuram; Black, Robert E; Crook, Derrick W

2008-01-01

Multidrug resistance (MDR), specifically to ampicillin and chloramphenicol, has complicated the treatment of Haemophilus influenzae type b (Hib) meningitis. This is worsened by use of prior antibiotics, which limits identification of the causative agent by culture and increases reliance on antigen detection. We aimed to develop a PCR assay for detecting the family of Haemophilus integrating and conjugative elements (ICEs) represented by ICEHin1056 among antibiotic resistant Hib, and then apply this directly to CSF to diagnose Hib meningitis and predict organism susceptibility, irrespective of culture results. Primers specific for orf 51 of ICEHin1056 were designed and multiplexed with Bex primers, specific for H. influenzae, and tested on culture positive and negative cases. Of 73 Hib isolates, orf 51 PCR amplicons, predicting the presence of ICEs, were found in all 33 MDR isolates while only in 1 of 33 sensitive strains. The remaining 7 ampicillin susceptible, chloramphenicol and tetracycline resistant strains did not produce a PCR product to orf 51. PCR amplification from CSF specimens of these culture positive cases produced identical results with 100% and 97% positive and negative predictive values, respectively. Multiplex PCR to detect Bex and orf 51 identified another 16 MDR Hib cases among 81 culture-negative CSF samples. Direct PCR for orf 51 in CSF identified resistance pattern of 51% more Hib strains than culture alone (110 versus 73). The ability to detect MDR, in culture negative Hib meningitis cases has significant implications for better directing antibiotic treatment of meningitis cases and thus for preventing disability and death.

Antimicrobial resistance in diarrheagenic Escherichia coli from ready-to-eat foods.

PubMed

Lima, Cíntia Matos; Souza, Ingrid Evelyn Gomes Lima; Dos Santos Alves, Taila; Leite, Clícia Capibaribe; Evangelista-Barreto, Norma Suely; de Castro Almeida, Rogeria Comastri

2017-10-01

Certain subgroups of Escherichia coli have congenital or acquired virulence properties that allow them to cause a wide spectrum of disease. The aim of this study was to investigate the occurrence of diarrheagenic E. coli strains in ready-to-eat (RTE) foods produced in institutional, commercial and hotel restaurants in Salvador, Brazil. The presence of virulent isolates and antimicrobial resistance were evaluated. Four hundred forty-six samples were collected and grouped into cereals and vegetables, meat-based preparations, cooked salads, raw salads, garnishes, soups and sauces, desserts and juices. E. coli were detected using the most probable number method, the presence of virulence factors in isolates was determined by polymerase chain reaction (PCR) assays, and antibiotic resistance was analyzed using the disc diffusion method. In total, 15 isolates (3.1%) of E. coli were recovered; raw salads had the highest detection rate, 1.4%, followed by cooked salads, 0.8%; meat-based preparations, 0.4%; and cereals and vegetables, 0.4%. PCR assays showed that none of the isolates had the virulence genes cnf1, cnf2, eae , sta, lt1, stx1, stx2 or cdtB . The isolates showed resistance to nine antibiotics of the 15 tested, and the highest levels of resistance were found for sulfamethoxazole/trimethoprim, tetracycline, ampicillin, and chloramphenicol (13.3% of isolates for each antibiotic). One isolate from cooked salad had plasmid-mediated multidrug resistance to tetracycline, trimethoprim/sulfamethoxazole, ampicillin and chloramphenicol. These results suggest that RTE foods, especially raw salads, can be reservoirs of E. coli and facilitate the spread of antibiotic resistance genes to the gastrointestinal microbiota of humans.

Blue genes: An integrative laboratory to differentiate genetic transformation from gene mutation for underclassmen.

PubMed

Militello, Kevin T; Chang, Ming-Mei; Simon, Robert D; Lazatin, Justine C

2016-01-01

The ability of students to understand the relationship between genotype and phenotype, and the mechanisms by which genotypes and phenotypes can change is essential for students studying genetics. To this end, we have developed a four-week laboratory called Blue Genes, which is designed to help novice students discriminate between two mechanisms by which the genetic material can be altered: genetic transformation and gene mutation. In the first week of the laboratory, students incubate a plasmid DNA with calcium chloride-treated Escherichia coli JM109 cells and observe a phenotype change from ampicillin sensitive to ampicillin resistant and from white color to blue color on plates containing 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal) and isopropyl β-D-thiogalactopyranoside (IPTG). Over the course of the next three weeks, students use a battery of approaches including plasmid DNA isolation experiments, restriction maps, and PCR to differentiate between mutation and transformation. The students ultimately come to the conclusion that the changes in phenotypes are due to genetic transformation and not mutation based on the evidence generated over the four-week period. Pre-laboratory tests and post-laboratory tests indicate that this set of exercises is successful in helping students differentiate between transformation and mutation. The laboratory is designed for underclassmen and is a good prerequisite for an apprentice-based research opportunity, although it is not designed as a class based research experience. Potential modifications and future directions of the laboratory based upon student experiences and assessment are presented. © 2015 The International Union of Biochemistry and Molecular Biology.

Community-acquired urinary tract infections in children: pathogens, antibiotic susceptibility and seasonal changes.

PubMed

Yolbaş, I; Tekin, R; Kelekci, S; Tekin, A; Okur, M H; Ece, A; Gunes, A; Sen, V

2013-04-01

Urinary tract infections (UTIs) are common infections affecting children. The aim of our study is to determine microorganisms that cause community-acquired urinary tract infections and their antibiotic susceptibility in children. Our investigation includes 150 cases which has positive urine culture. The cases are detected at Pediatric Polyclinics of Dicle University between June 2010 and June 2011. The study included 118 (78.7%) female and 32 (21.3%) male children. Urinary tract infections were seen in autumn 10.7% (n = 16), summer 35.3% (n = 53), winter 30.7% (n = 46) and spring 23.3% (n = 35). The culture results indicated 75.3% (n = 113) Escherichia coli; 20.7% (n = 31) Klebsiella; 2.7% (n = 4) Proteus and % 1.3 (n = 2) Pseudomonas. The antibiotic resistance against Escherichia coli was found out is amikacin (3%), ertapenem (7%), imipenem (0%), meropenem (0%), nitrofurantoin (9%), trimethoprim/sulfamethoxazole (58%), piperacillin (83%), amoxicillin/clavulanate (50%), ampicillin/sulbactam (65%), cefazolin (54%), cefotaxime (51%), cefuroxime sodium (51% ) and tetracycline (68%). The resistance ratios of Klebsiella are amikacin (0%), imipenem (0%), levofloxacin (0%), meropenem (0%), amoxicillin/clavulanate (57%), ampicillin/sulbactam (79%), ceftriaxone (68%), cefuroxime sodium (74%) and trimethoprim/sulfamethoxazole (61%). The results represent the increasing antibiotic resistance against microorganisms among the community-acquired UTI patients in a developing country such as Turkey. So, the physicians should consider resistance status of the infectious agent and choose effective antibiotics which are nitrofurantoin and cefoxitin for their empirical antibiotic treatment. Furthermore, they should be trained about selection of more effective antibiotics and check the regional studies regularly.

Antibiotic resistance patterns of urinary tract pathogens in Turkish children.

PubMed

Gunduz, Suzan; Uludağ Altun, Hatice

2018-01-01

Knowledge of local antimicrobial resistance patterns is essential for evidence- based empirical antibiotic prescribing. We aimed to investigate the distribution and changes in causative agents of urinary tract infections in children and the resistance rates, and to recommend the most appropriate antibiotics. In this retrospective study, we evaluated causative agents and antimicrobial resistance in urine isolates from the positive community from September 2014 to April 2016 in a single hospital in Ankara, Turkey. A total of 850 positive urine cultures were identified, of which 588 (69.2%) were from girls and 262 (30.8%) were from boys. Their mean age was 36.5 ± 45.0 months. The most common causative agent was Escherichia coli (64.2% of cases) followed by Klebsiella pneumoniae (14.9%). The overall resistance to ampicillin (62.6%), cephalothin (44.2%), co-trimoxazole (29.8%) and cefuroxime (28.7%) was significant. No resistance to imipenem was detected in the isolates. The least resistance was for amikacin, ceftriaxone, ciprofloxacin and cefepime (0.1, 2.4, 7.5 and 8.3%, respectively). Imipenem was the most active agent against E. coli followed by amikacin (0.2%), ceftriaxone (2.7%) and nitrofurantoin (5.1%). High resistance rates to nitrofurantoin were detected in K. pneumoniae, Proteus and Enterobacteriae . E. coli was the most common causative agent of urinary tract infection in children. Ampicillin, trimethoprim-sulfometaxazole, cephalothin and cefuroxim had the highest resistance rates against urinary tract pathogens in our center. For oral empirical antibiotherapy, cefixime is the most appropriate choice so as to include Klebsiella strains.

Antibacterial and antibiotic potentiating activities of tropical marine sponge extracts.

PubMed

Beesoo, Rima; Bhagooli, Ranjeet; Neergheen-Bhujun, Vidushi S; Li, Wen-Wu; Kagansky, Alexander; Bahorun, Theeshan

2017-06-01

Increasing prevalence of antibiotic resistance has led research to focus on discovering new antimicrobial agents derived from the marine biome. Although ample studies have investigated sponges for their bioactive metabolites with promising prospects in drug discovery, the potentiating effects of sponge extracts on antibiotics still remains to be expounded. The present study aimed to investigate the antibacterial capacity of seven tropical sponges collected from Mauritian waters and their modulatory effect in association with three conventional antibiotics namely chloramphenicol, ampicillin and tetracycline. Disc diffusion assay was used to determine the inhibition zone diameter (IZD) of the sponge total crude extracts (CE), hexane (HF), ethyl acetate (EAF) and aqueous (AF) fractions against nine standard bacterial isolates whereas broth microdilution method was used to determine their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and antibiotic potentiating activity of the most active sponge extract. MIC values of the sponge extracts ranged from 0.039 to 1.25mg/mL. Extracts from Neopetrosia exigua rich in beta-sitosterol and cholesterol displayed the widest activity spectrum against the 9 tested bacterial isolates whilst the best antibacterial profile was observed by its EAF particularly against Staphylococcus aureus and Bacillus cereus with MIC and MBC values of 0.039mg/mL and 0.078mg/mL, respectively. The greatest antibiotic potentiating effect was obtained with the EAF of N. exigua (MIC/2) and ampicillin combination against S. aureus. These findings suggest that the antibacterial properties of the tested marine sponge extracts may provide an alternative and complementary strategy to manage bacterial infections. Copyright © 2017 Elsevier Inc. All rights reserved.

Increase of β-Lactam-Resistant Invasive Haemophilus influenzae in Sweden, 1997 to 2010

PubMed Central

Resman, Fredrik; Ristovski, Mikael; Forsgren, Arne; Kaijser, Bertil; Kronvall, Göran; Medstrand, Patrik; Melander, Eva; Odenholt, Inga

2012-01-01

The proportions of Haemophilus influenzae resistant to ampicillin and other β-lactam antibiotics have been low in Sweden compared to other countries in the Western world. However, a near-doubled proportion of nasopharyngeal Swedish H. influenzae isolates with resistance to β-lactams has been observed in the last decade. In the present study, the epidemiology and mechanisms of antimicrobial resistance of H. influenzae isolates from blood and cerebrospinal fluid in southern Sweden from 1997 to 2010 (n = 465) were studied. Antimicrobial susceptibility testing was performed using disk diffusion, and isolates with resistance to any tested β-lactam were further analyzed in detail. We identified a significantly increased (P = 0.03) proportion of β-lactam-resistant invasive H. influenzae during the study period, which was mainly attributed to a significant recent increase of β-lactamase-negative β-lactam-resistant isolates (P = 0.04). Furthermore, invasive β-lactamase-negative β-lactam-resistant H. influenzae isolates from 2007 and onwards were found in higher proportions than the corresponding proportions of nasopharyngeal isolates in a national survey. Multiple-locus sequence typing (MLST) of this group of isolates did not completely separate isolates with different resistance phenotypes. However, one cluster of β-lactamase-negative ampicillin-resistant (BLNAR) isolates was identified, and it included isolates from all geographical areas. A truncated variant of a β-lactamase gene with a promoter deletion, blaTEM-1-PΔ dominated among the β-lactamase-positive H. influenzae isolates. Our results show that the proportions of β-lactam-resistant invasive H. influenzae have increased in Sweden in the last decade. PMID:22687505

Transmission of Mannheimia haemolytica from domestic sheep (Ovis aries) to bighorn sheep (Ovis canadensis): unequivocal demonstration with green fluorescent protein-tagged organisms.

PubMed

Lawrence, Paulraj K; Shanthalingam, Sudarvili; Dassanayake, Rohana P; Subramaniam, Renuka; Herndon, Caroline N; Knowles, Donald P; Rurangirwa, Fred R; Foreyt, William J; Wayman, Gary; Marciel, Ann Marie; Highlander, Sarah K; Srikumaran, Subramaniam

2010-07-01

Previous studies demonstrated that bighorn sheep (Ovis canadensis) died of pneumonia when commingled with domestic sheep (Ovis aries) but did not conclusively prove that the responsible pathogens were transmitted from domestic to bighorn sheep. The objective of this study was to determine, unambiguously, whether Mannheimia haemolytica can be transmitted from domestic to bighorn sheep when they commingle. Four isolates of M. haemolytica were obtained from the pharynx of two of four domestic sheep and tagged with a plasmid carrying the genes for green fluorescent protein (GFP) and ampicillin resistance (AP(R)). Four domestic sheep, colonized with the tagged bacteria, were kept about 10 m apart from four bighorn sheep for 1 mo with no clinical signs of pneumonia observed in the bighorn sheep during that period. The domestic and bighorn sheep were then allowed to have fence-line contact for 2 mo. During that period, three bighorn sheep acquired the tagged bacteria from the domestic sheep. At the end of the 2 mo of fence-line contact, the animals were allowed to commingle. All four bighorn sheep died 2 days to 9 days following commingling. The lungs from all four bighorn sheep showed gross and histopathologic lesions characteristic of M. haemolytica pneumonia. Tagged M. haemolytica were isolated from all four bighorn sheep, as confirmed by growth in ampicillin-containing culture medium, PCR-amplification of genes encoding GFP and Ap(R), and immunofluorescent staining of GFP. These results unequivocally demonstrate transmission of M. haemolytica from domestic to bighorn sheep, resulting in pneumonia and death of bighorn sheep.

Antibiotic susceptibility patterns and prevalence of group B Streptococcus isolated from pregnant women in Misiones, Argentina

PubMed Central

Quiroga, M.; Pegels, E.; Oviedo, P.; Pereyra, E.; Vergara, M.

2008-01-01

This study was performed to determine the susceptibility patterns and the colonization rate of Group B Streptococcus (GBS) in a population of pregnant women. From January 2004 to December 2006, vaginal-rectal swabs were obtained from 1105 women attending Dr. Ramón Madariaga Hospital, in Posadas, Misiones, Argentina. The carriage rate of GBS among pregnant women was 7.6%. A total of 62 GBS strains were randomly selected for in vitro susceptibility testing to penicillin G, ampicillin, tetracycline, levofloxacin, gatifloxacin, ciprofloxacin, quinupristin-dalfopristin, linezolid, vancomycin, rifampicin, trimethoprim- sulfametoxazol, nitrofurantoin, gentamicin, clindamycin and erythromycin, and determination of resistance phenotypes. No resistance to penicillin, ampicillin, quinupristin-dalfopristin, linezolid, and vancomycin was found. Of the isolates examined 96.8%, 98.3%, 46.8%, and 29.0% were susceptible to rifampicin, nitrofurantoin, trimethoprim-sulfametoxazol and tetracycline, respectively. Rank order of susceptibility for the quinolones was: gatifloxacin (98.4%) > levofloxacin (93.5%) > ciprofloxacin (64.5%). The rate of resistance to erythromycin (9.7%) was higher than that of other reports from Argentina. High-level resistance to gentamicin was not detected in any of the isolates. Based on our finding of 50% of GBS isolates with MIC to gentamicin equal o lower than 8 μg/ml, a concentration used in one of the selective media recommended for GBS isolation, we suggested, at least in our population, the use of nalidixic acid and colistin in selective media with the aim to improve the sensitivity of screening cultures for GBS carriage in women. PMID:24031210

[Changes in ion transport through membranes, ATPase activity and antibiotics effects in Enterococcus hirae after low intensity electromagnetic irradiation of 51,8 and 53,0 GHz frequencies].

PubMed

Torgomian, É; Oganian, V; Blbulian, C; Trchunian, A

2013-01-01

It was ascertained that one-hour exposure of Enterococcus hirae ATCC9790 bacteria grown under anaerobe condition during sugar (glucose) fermentation to coherent electromagnetic irradiation (EMI) of 51,8 and 53,0 GHz frequencies or millimeter waves (5,79 and 5,66 mm wavelengths) of low-intensity (flux capacity of 0,06 mW/sm2) caused a significant decrease in energy-dependent H+ and K+ transports across the membranes of whole cells. Therewith, K+ influx into cells was appreciably less at the frequency of 53,0 GHz. Likewise, a significant decrease of total and N,N'-dicyclohexylcarbodiimide-sensitive ATPase activity of the membrane vesicles occurred after EMI of 51,8 and 53,0 GHz. These results indicated the input of membranous changes in bacterial action of low intensity extremely high frequency EMI, when the F0F1-ATPase was probably playing a key role. Additionally, the enhancement of the effects of antibiotics--ceftriaxone, kanamycin and ampicillin at their minimal inhibitory concentrations (100, 200 and 1,4 microM, correspondingly) on the bacterial growth by these irradiations was shown. Also, combined action of EMI and antibiotics depressed strongly H+ and K+ fluxes across membrane. Especially, H+ flux was more sensitive to the action of ceftriaxone, but K+ flux was sensitive to kanamycin. All these made the assumption that EMI of 51,8 and 53,0 GHz frequencies, especially 53,0 GHz, was followed by change in bacterial sensitivity toward antibiotics that was more obvious with ceftriaxone and ampicillin.

In vitro evaluation of Augmentin by broth microdilution and disk diffusion susceptibility testing: regression analysis, tentative interpretive criteria, and quality control limits.

PubMed Central

Fuchs, P C; Barry, A L; Thornsberry, C; Gavan, T L; Jones, R N

1983-01-01

Augmentin (Beecham Laboratories, Bristol, Tenn.), a combination drug consisting of two parts amoxicillin to one part clavulanic acid and a potent beta-lactamase inhibitor, was evaluated in vitro in comparison with ampicillin or amoxicillin or both for its inhibitory and bactericidal activities against selected clinical isolates. Regression analysis was performed and tentative disk diffusion susceptibility breakpoints were determined. A multicenter performance study of the disk diffusion test was conducted with three quality control organisms to determine tentative quality control limits. All methicillin-susceptible staphylococci and Haemophilus influenzae isolates were susceptible to Augmentin, although the minimal inhibitory concentrations for beta-lactamase-producing strains of both groups were, on the average, fourfold higher than those for enzyme-negative strains. Among the Enterobacteriaceae, Augmentin exhibited significantly greater activity than did ampicillin against Klebsiella pneumoniae, Citrobacter diversus, Proteus vulgaris, and about one-third of the Escherichia coli strains tested. Bactericidal activity usually occurred at the minimal inhibitory concentration. There was a slight inoculum concentration effect on the Augmentin minimal inhibitory concentrations. On the basis of regression and error rate-bounded analyses, the suggested interpretive disk diffusion susceptibility breakpoints for Augmentin are: susceptible, greater than or equal to 18 mm; resistant, less than or equal to 13 mm (gram-negative bacilli); and susceptible, greater than or equal to 20 mm (staphylococci and H. influenzae). The use of a beta-lactamase-producing organism, such as E. coli Beecham 1532, is recommended for quality assurance of Augmentin susceptibility testing. PMID:6625554

Morphological, biochemical, physiological and molecular aspects of the response of Fusobacterium nucleatum exposed to subinhibitory concentrations of antimicrobials.

PubMed

de Souza Filho, Job Alves; Diniz, Cláudio Galuppo; Barbosa, Natália Bento; de Freitas, Michele Cristine Ribeiro; Lopes Neves, Mariana Silva; da Gama Mazzei, Rafaella Nogueira; Gameiro, Jacy; Coelho, Cíntia Marques; da Silva, Vânia Lúcia

2012-12-01

Subinhibitory concentrations (SICs) of antimicrobials may result in alterations in bacterial biology with implications for its potential aggression. This has considerable importance for the resident microbiota. Our aim was to analyze the effects of SICs of antimicrobials on the morphological, biochemical, physiological and molecular characteristics of the resident anaerobic Fusobacterium nucleatum. Fourteen strains were obtained from F. nucleatum ATCC 25586, selected by culturing on SICs of ampicillin, ampicillin/sulbactam, clindamycin, chloramphenicol, levofloxacin, metronidazole and piperacillin/tazobactam and subsequent culturing in the absence of drugs. Antimicrobial susceptibility, bacterial morphology, biochemical profiles and biofilm formation were evaluated. Genotyping and analysis of protein profiles were also performed. The antimicrobial susceptibility patterns showed that most of the derived strains were less sensitive to the antimicrobials, even after culturing them without drugs. Morphological and cell complexity alterations were observed, mainly in strains grown in SICs of β-lactam; these strains also expressed a reduced ability for biofilm formation. The other strains showed an increase in biofilm formation but no apparent morphological changes. Alterations were observed in the carbohydrate metabolism patterns and in the activity of microbial enzymes. Several proteins were positively or negatively regulated and there was polymorphism in the DNA from all derived strains. Therefore, SICs of antimicrobials induce alterations in F. nucleatum, which directly impact its biology. These results emphasize the risk of inadequate antibioticotherapy, which may have serious implications for clinical microbiology and infectious diseases and also may interfere with the host-bacteria relationship. Copyright © 2012 Elsevier Ltd. All rights reserved.

Obstetricians' attitudes, subjective norms, perceived controls, and intentions on antibiotic prophylaxis in caesarean section.

PubMed

Liabsuetrakul, Tippawan; Chongsuvivatwong, Virasakdi; Lumbiganon, Pisake; Lindmark, Gunilla

2003-11-01

Over 10% of current births in all countries of the world are delivered by caesarean section. Single-dose ampicillin or cefazolin administered after cord clamping has been proven to be effective for the prevention of post-caesarean infections as indicated in many randomised trials and reviews in the Cochrane Library. This study aimed to determine three determinants of behavioural intention using the theory of planned behaviour: attitudes, subjective norms, and perceived controls. Intentions were examined for five aspects of the use of antibiotic prophylaxis, namely whether or not antibiotics were used, used in all caesarean sections, after rather than before cord clamping, whether ampicillin/cefazolin or broader-spectrum antibiotics were used, and whether single or multiple doses were given. Fifty obstetricians selected from university, regional, and general hospitals in southern Thailand, were surveyed using a questionnaire and in-depth interview. Their intentions to use a single dose and to use in all cases were low, and this was related to negative attitudes and reference groups who did not approve of the single dose. The negative attitude was based on scepticism concerning the applicability of well-equipped trials from the developed world and fear of consequences of post-caesarean infections. Norms carried over from residency training had more long-term influence in their practice than newer information from books or journals. Perceived external controls on their practice were less predictive of intentions. Intentions were only partly predictive of behaviour. Changing attitudes, introducing evidence-based information into residency training and strengthening control systems in the hospital are essential to improve intentions.

Synergistic effect of artocarpin on antibacterial activity of some antibiotics against methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli.

PubMed

Septama, Abdi Wira; Panichayupakaranant, Pharkphoom

2016-01-01

Antibacterial resistance has dramatically increased and resulted in serious health problems worldwide. One appealing strategy to overcome this resistance problem is the use of combinations of antibacterial compounds to increase their potency. The objective of this study is to determine the synergistic effects of artocarpin for ampicillin, norfloxacin, and tetracycline against methicillin-resistant Staphylococcus aureus (MRSA) as well as the Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli. A broth microdilution method (1.95-250 µg/mL) was used to determine the minimum inhibitory concentration (MIC) of artocarpin and the antibiotics. Any synergistic effects were evaluated at their own MIC using the checkerboard method and a time-kill assay at 37 °C for 24 h. Artocarpin showed antibacterial activity against MRSA and E. coli with an MIC value of 62.5 µg/mL, and against P. aeruginosa with an MIC value of 250 µg/mL. The interaction of artocarpin with all tested antibiotics produced synergistic effects against MRSA with a fractional inhibitory concentration index (FICI) of 0.15-0.37. In addition, a combination of artocarpin and norfloxacin showed a synergistic effect against E. coli with an FICI value of 0.37, while the combinations of artocarpin and tetracycline as well as artocarpin and norfloxacin exhibited synergy interactions against P. aeruginosa with FICI values of 0.24 and 0.37, respectively. Time-kill assays indicated that artocarpin enhanced the antimicrobial activities of tetracycline, ampicillin, and norfloxacin against MRSA as well as Gram-negative bacteria.

A synergistic effect of artocarpanone from Artocarpus heterophyllus L. (Moraceae) on the antibacterial activity of selected antibiotics and cell membrane permeability

PubMed Central

Septama, Abdi Wira; Xiao, Jianbo; Panichayupakaranant, Pharkphoom

2017-01-01

Aim/Backgrounds: Artocarpanone isolated from Artocarpus heterophyllus L. (Moraceae) exhibits antibacterial activity. The present study investigated synergistic activity between artocarpanone and tetracycline, ampicillin, and norfloxacin, respectively, against methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Escherichia coli. Materials and Methods: A broth microdilution method was used for evaluating antibacterial susceptibility. Synergistic effects were identified using a checkerboard method, and a bacterial cell membrane disruption was investigated by assay of released 260 nm absorbing materials following bacteriolysis. Results and Discussion: Artocarpanone exhibited weak antibacterial activity against MRSA and P. aeruginosa with minimum inhibitory concentrations values of 125 and 500 μg/mL, respectively. However, the compound showed strong antibacterial activity against E. coli (7.8 μg/mL). The interaction between artocarpanone and all tested antibiotics revealed indifference and additive effects against P. aeruginosa and E. coli (fractional inhibitory concentration index [FICI] values of 0.75-1.25). The combination of artocarpanone (31.2 μg/mL) and norfloxacin (3.9 μg/mL) resulted in synergistic antibacterial activity against MRSA, with an FICI of 0.28, while the interaction between artocarpanone and tetracycline, and ampicillin showed an additive effect, with an FICI value of 0.5. A time-kill assay also indicated that artocarpanone had a synergistic effect on the antibacterial activity of norfloxacin. In addition, the combination of artocarpanone and norfloxacin altered the membrane permeability of MRSA. Conclusion: These findings suggest that artocarpanone may be used to enhance the antibacterial activity of norfloxacin against MRSA. PMID:28512600

Interaction of Zwitterionic Penicillins with the OmpF Channel Facilitates Their Translocation

PubMed Central

Danelon, Christophe; Nestorovich, Ekaterina M.; Winterhalter, Mathias; Ceccarelli, Matteo; Bezrukov, Sergey M.

2006-01-01

To study translocation of β-lactam antibiotics of different size and charge across the outer bacterial membrane, we combine an analysis of ion currents through single trimeric outer membrane protein F (OmpF) porins in planar lipid bilayers with molecular dynamics simulations. Because the size of penicillin molecules is close to the size of the narrowest part of the OmpF pore, penicillins occlude the pore during their translocation. Favorably interacting penicillins cause time-resolvable transient blockages of the small-ion current through the channel and thereby provide information about their dynamics within the pore. Analyzing these random fluctuations, we find that ampicillin and amoxicillin have a relatively high affinity for OmpF. In contrast, no or only a weak interaction is detected for carbenicillin, azlocillin, and piperacillin. Molecular dynamics simulations suggest a possible pathway of these drugs through the OmpF channel and rationalize our experimental findings. For zwitterionic ampicillin and amoxicillin, we identify a region of binding sites near the narrowest part of the channel pore. Interactions with these sites partially compensate for the entropic cost of drug confinement by the channel. Whereas azlocillin and piperacillin are clearly too big to pass through the channel constriction, dianionic carbenicillin does not find an efficient binding region in the constriction zone. Carbenicillin's favorable interactions are limited to the extracellular vestibule. These observations confirm our earlier suggestion that a set of high-affinity sites at the narrowest part of the OmpF channel improves a drug's ability to cross the membrane via the pore. PMID:16339889

Seasonal Variation in Penicillin Use in Mexico and Brazil: Analysis of the Impact of Over-the-Counter Restrictions

PubMed Central

Santa-Ana-Tellez, Yared; Mantel-Teeuwisse, Aukje K.; Leufkens, Hubert G. M.

2014-01-01

During 2010, Mexico and Brazil implemented policies to enforce existing laws of restricting over-the-counter sales of antibiotics. We determined if the enforcement led to more appropriate antibiotic use by measuring changes in seasonal variation of penicillin use. We used retail quarterly sales data in defined daily doses per 1,000 inhabitant-days (DDD/TID) from IMS Health from the private sector in Mexico and Brazil from the first quarter of 2007 to the first quarter of 2013. This database contains information on volume of antibiotics sold in retail pharmacies using information from wholesalers. We used interrupted time-series models controlling for external factors with the use of antihypertensives with interaction terms to assess changes in trend, level, and variation in use between quarters for total penicillin use and by active substance. The most used penicillin was amoxicillin, followed by amoxicillin-clavulanic acid and ampicillin (minimal use in Brazil). Before the restrictions, the seasonal variation in penicillin use was 1.1 DDD/TID in Mexico and 0.8 DDD/TID in Brazil. In Mexico, we estimated a significant decrease in the seasonal variation of 0.4 DDD/TID after the restriction, mainly due to changes in seasonal variation of amoxicillin and ampicillin. In Brazil, the seasonal variation did not change significantly, overall and in the breakdown by individual active substances. For Mexico, inappropriate penicillin use may have diminished after the restrictions were enforced. For Brazil, increasing use and no change in seasonal variation suggest that further efforts are needed to reduce inappropriate penicillin use. PMID:25313222

Comparison of the effect of penicillins versus erythromycin in preventing neonatal group B streptococcus infection in active carriers following preterm prelabor rupture of membranes.

PubMed

Yeung, Sik Wing; Sahota, Daljit Singh; Leung, Tak Yeung

2014-06-01

To compare the incidence of neonatal group B streptococcus (GBS) infection in active GBS carriers with preterm prelabor rupture of membranes (PPROMs) after penicillins and erythromycin prophylaxis. Patients diagnosed to have PPROM between 2004 and 2009 inclusive were treated using erythromycin (erythromycin group), ampicillin, amoxicillin or co-amoxiclav (penicillin group), or no antibiotics (control group) according to department protocols depending on their gestation and their GBS status at the time of presentation. Patients receiving both erythromycin and penicillins were included in the penicillin group. The incidence of neonatal GBS infection was compared between groups categorized according to the antibiotic regime received. A total of 680 women were diagnosed to have PPROM of which 85 (12.5%) were active GBS carriers. GBS isolates were 100% sensitive to penicillins but only 35% were sensitive to erythromycin. There were 16, 22, and 47 patients in the penicillin, erythromycin, and control groups, respectively. The incidence of neonatal GBS infection in the three groups was 0%, 36%, and 13%, respectively, and was statistically significant (p = 0.023). Penicillins are more effective than erythromycin in preventing neonatal GBS infection in women with PPROM who were active GBS carriers. Because most women do not know their GBS status at the time of PPROM and it is practically difficult to identify the active carriers before delivery, ampicillin/amoxicillin should be used as a prophylactic antibiotic for active GBS carriers and women with unknown GBS carriage status to prevent neonatal GBS infection following PPROM. Copyright © 2014. Published by Elsevier B.V.

Identification and antimicrobial resistance of microflora colonizing feral pig (Sus scrofa) of Brazilian Pantanal.

PubMed Central

Lessa, SS; Paes, RCS; Santoro, PN; Mauro, RA; Vieira-da-Motta, O

2011-01-01

Antimicrobial resistance of bacteria is a worldwide problem affecting wild life by living with resistant bacteria in the environment. This study presents a discussion of outside factors environment on microflora of feral pigs (Sus scrofa) from Brazilian Pantanal. Animals had samples collected from six different body sites coming from two separated geographic areas, Nhecolandia and Rio Negro regions. With routine biochemical tests and commercial kits 516 bacteria were identified, with 240 Gram-positive, predominantly staphylococci (36) and enterococci (186) strains. Among Gram-negative (GN) bacteria the predominant specimens of Enterobacteriaceae (247) mainly represented by Serratia spp. (105), Escherichia coli (50), and Enterobacter spp. (40) and specimens not identified (7). Antimicrobial susceptibility was tested against 17 drugs by agar diffusion method. Staphylococci were negative to production of enterotoxins and TSST-1, with all strains sensitive towards four drugs and highest resistance toward ampicillin (17%). Enterococci presented the highest sensitivity against vancomycin (98%), ampicillin (94%) and tetracycline (90%), and highest resistance pattern toward oxacillin (99%), clindamycin (83%), and cotrimoxazole (54%). In GN the highest resistance was observed with Serratia marcescens against CFL (98%), AMC (66%) and AMP (60%) and all drugs was most effective against E. coli SUT, TET (100%), AMP, TOB (98%), GEN, CLO (95%), CFO, CIP (93%). The results show a new profile of oxacillin-resistant enterococci from Brazilian feral pigs and suggest a limited residue and spreading of antimicrobials in the environment, possibly because of low anthropogenic impact reflected by the drug susceptibility profile of bacteria isolated. PMID:24031689

The Epidemiology, Management, and Outcomes of Bacterial Meningitis in Infants.

PubMed

Ouchenir, Lynda; Renaud, Christian; Khan, Sarah; Bitnun, Ari; Boisvert, Andree-Anne; McDonald, Jane; Bowes, Jennifer; Brophy, Jason; Barton, Michelle; Ting, Joseph; Roberts, Ashley; Hawkes, Michael; Robinson, Joan L

2017-07-01

The pathogens that cause bacterial meningitis in infants and their antimicrobial susceptibilities may have changed in this era of increasing antimicrobial resistance, use of conjugated vaccines, and maternal antibiotic prophylaxis for group B Streptococcus (GBS). The objective was to determine the optimal empirical antibiotics for bacterial meningitis in early infancy. This was a cohort study of infants <90 days of age with bacterial meningitis at 7 pediatric tertiary care hospitals across Canada in 2013 and 2014. There were 113 patients diagnosed with proven meningitis ( n = 63) or suspected meningitis ( n = 50) presented at median 19 days of age, with 63 patients (56%) presenting a diagnosis from home. Predominant pathogens were Escherichia coli ( n = 37; 33%) and GBS ( n = 35; 31%). Two of 15 patients presenting meningitis on day 0 to 6 had isolates resistant to both ampicillin and gentamicin ( E coli and Haemophilus influenzae type B). Six of 60 infants presenting a diagnosis of meningitis from home from day 7 to 90 had isolates, for which cefotaxime would be a poor choice ( Listeria monocytogenes [ n = 3], Enterobacter cloacae , Cronobacter sakazakii , and Pseudomonas stutzeri ). Sequelae were documented in 84 infants (74%), including 8 deaths (7%). E coli and GBS remain the most common causes of bacterial meningitis in the first 90 days of life. For empirical therapy of suspected bacterial meningitis, one should consider a third-generation cephalosporin (plus ampicillin for at least the first month), potentially substituting a carbapenem for the cephalosporin if there is evidence for Gram-negative meningitis. Copyright © 2017 by the American Academy of Pediatrics.

Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis.

PubMed

Eshetie, Setegn; Tarekegn, Fentahun; Moges, Feleke; Amsalu, Anteneh; Birhan, Wubet; Huruy, Kahsay

2016-11-21

The burden of methicillin resistant Staphylococcus aureus is a major public health concern worldwide; however the overall epidemiology of multidrug resistant strains is neither coordinated nor harmonized, particularly in developing countries including Ethiopia. Therefore, the aim of this meta-analysis was to assess the burden of methicillin resistant Staphylococcos aureus and its antibiotic resistance pattern in Ethiopia at large. PubMed, Google Scholar, and lancet databases were searched and a total of 20 studies have been selected for meta-analysis. Six authors have independently extracts data on the prevalence of methicillin resistant Staphylococcus aureus among clinical isolates of Staphylococcus aureus. Statistical analysis was achieved by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3) softwares. The overall prevalence of methicillin resistant Staphylococcus aureus and its antibiotic resistance pattern were pooled by using the forest plot, table and figure with 95% CI. The pooled prevalence of methicillin resistant Staphylococcus aureus was 32.5% (95% CI, 24.1 to 40.9%). Moreover, methicillin resistant Staphylococcus aureus strains were found to be highly resistant to penicillin, ampicillin, erythromycin, and amoxicillin, with a pooled resistance ratio of 99.1, 98.1, 97.2 and 97.1%, respectively. On the other hand, comparably low levels of resistance ratio were noted to vancomycin, 5.3%. The overall burden of methicillin resistant Staphylococcus aureus is considerably high, besides these strains showed extreme resistance to penicillin, ampicillin, erythromycin and amoxicillin. In principle, appropriate use of antibiotics, applying safety precautions are the key to reduce the spread of multidrug resistant strains, methicillin resistant Staphylococcus aureus in particular.

Effects of antibiotic treatment on the lactobacillus composition of vaginal microbiota.

PubMed

Melkumyan, A R; Priputnevich, T V; Ankirskaya, A S; Murav'eva, V V; Lubasovskaya, L A

2015-04-01

We analyzed sensitivity of 123 vaginal lactobacillus strains to antibacterial substances. All lactobacillus strains were sensitive to ampicillin, cefazolin, cefotaxime, and vancomycin, and insensitive to metronidazole, trimethoprim/sulfamethoxazole, and levofloxacin. Lactobacillus strains demonstrated different sensitivity to gentamycin, clindamycin, erythromycin, ciprofloxacin, and tetracycline. The phenomenon of preferential selective influence of antibacterial drugs on the composition of lactobacilli of the vaginal microbiota, in which some lactobacilli survive as part of the vaginal microbiota and have a selective advantage over other types of lactobacilli, should be taken into account during treatment of vaginal infections and dysbiosis.

Surveillance of group B streptococcal toxic shock-like syndrome in nonpregnant adults and characterization of the strains in Japan.

PubMed

Chang, Bin; Ikebe, Tadayoshi; Wada, Akihito; Ogata, Kikuyo; Tomita, Masaaki; Katsukawa, Chihiro; Kawahara, Ryuji; Suzuki, Rieko; Endo, Miyoko; Isobe, Junko; Tanaka, Daisuke; Hirasawa, Kyoko; Watanabe, Haruo

2006-06-01

Nine group B streptococci (GBS) strains were isolated from five toxic shock-like syndrome cases of nonpregnant adults in Japan from 2001 to 2005. All of them were identified as Streptococcus agalactiae. The serotypes of these strains were Ib, III, V, and VII. Pulsed-field gel electrophoresis revealed that the patterns of the strains isolated from the different patients were variable. Antimicrobial susceptibility tests showed that all of the strains were susceptible to penicillin G, ampicillin, cefotaxime, clindamycin, and telithromycin. One strain showed intermediate resistance to erythromycin.

Identification of Mycobacterial Genes Involved in Antibiotic Sensitivity: Implications for the Treatment of Tuberculosis with β-Lactam-Containing Regimens

PubMed Central

Viswanathan, Gopinath; Yadav, Sangya

2017-01-01

ABSTRACT In a Mycobacterium smegmatis mutant library screen, transposon mutants with insertions in fhaA, dprE2, rpsT, and parA displayed hypersusceptibility to antibiotics, including the β-lactams meropenem, ampicillin, amoxicillin, and cefotaxime. Sub-MIC levels of octoclothepin, a psychotic drug inhibiting ParA, phenocopied the parA insertion and enhanced the bactericidal activity of meropenem against Mycobacterium tuberculosis in combination with clavulanate. Our study identifies novel factors associated with antibiotic resistance, with implications in repurposing β-lactams for tuberculosis treatment. PMID:28438925

Behavior of pharmaceuticals in waste water treatment plant in Japan.

PubMed

Matsuo, H; Sakamoto, H; Arizono, K; Shinohara, R

2011-07-01

The fate of pharmaceuticals in a wastewater treatment plant (WWTP) in Kumamoto, Japan with activated sludge treatment is reported. Selected pharmaceuticals were detected in influent. Results from the present study confirmed that Acetaminophen, Amoxicillin, Ampicillin and Famotidine were removed at a high rate (>90% efficiency). In contrast, removal efficiency of Ketoprofen, Losartan, Oseltamivir, Carbamazepine, and Diclofenac was relatively low (<50%). The selected pharmaceuticals were also detected in raw sludge. In digestive process, Indomethacin, Atenolol, Famotidine, Trimethoprim and Cyclofosamide were removed at a high (>70% efficiency). On the other hand, removal of Carbamazepine, Ketoprofen and Diclofenac was not efficient (<50%).