Occurrence Of Antibiotic-resistant Bacteria Research Articles

Occurrence of Ciprofloxacin‐, Trimethoprim‐Sulfamethoxazole‐, and Vancomycin‐Resistant Bacteria in a Municipal Wastewater Treatment Plant

The occurrence of antibiotic-resistant bacteria was evaluated in aqueous samples obtained from a municipal wastewater treatment plant. Samples collected from the influent, clarifier effluent, and disinfected effluent were assayed for fecal coliforms, E. coli, and enterococci exhibiting resistance to ciprofloxacin, trimethoprim-sulfamethoxazole, and vancomycin. Membrane filtration of samples was followed by plating on growth media containing various concentrations of antibiotic. Bacterial colonies on plates with antibiotic exposures greater than the clinical minimum inhibitory concentrations were counted and considered resistant. The numbers of drug-resistant organisms in influent ranged from nondetectable to 7 x 10(5) colony-forming units (CFU)/100 mL for fecal coliforms, nondetectable to 5 x 10(4) CFU/100 mL for E. coli, and nondetectable to 6 x 10(5) CFU/100 mL for enterococci. Fecal coliforms, E. coli, and enterococci with reduced susceptibility to antibiotics were also detected in influent and clarifier effluent; however, the disinfected effluent did not contain resistant bacteria. Species-level identification of enterococci revealed that resistant enterococci were predominantly E. faecalis.

Antibiotic resistant bacteria in faecal samples of apparently healthy individuals in Ado-Ekiti, Nigeria

The occurrence of antibiotic-resistant bacteria in faeces of apparently healthy individual volunteers was investigated. Faecal samples were collected from 216 individuals comprising 138 adults (70 males and 68 females) and 78 children aged between 4 months and 42 years (mean age was 30.2 months). Individuals on antibiotics were excluded from the study. Faecal samples were examined microbiologically for the presence of bacteria resistant to commonly employed antibiotics. Three hundred and eleven bacterial isolates were recovered; the bacteria detected included Escherichia coli (16.6%), Enterobacter sp. (13.6%), Salmonella sp. (13.2%), Proteus sp. (12.6%), Serratia sp. (11.9%), Klebsiella sp. (9.3%) and Citrobacter sp. (7.9%). Others included Hafnia sp. (3.6%), Providencia sp. (3.0%), Shigella sp. (3.0%), Edwardsiella sp. (2.6%), Yersinia sp. (2.0%) and Pseudomonas sp. (0.7%). Overall resistance to antibiotics was generally high; resistance to streptomycin (59.0%) was highest, while it was least to gentamicin (39.5%). High proportion (96%) of the isolates showed multiple antibiotic resistance (MAR) with 151 phenotypes. Journal of Science and Technology(Ghana) Vol. 27 (1) 2007: pp. 51-60

Occurrence of antibiotic-resistant bacteria and endotoxin associated with the land application of biosolids

The purpose of this study was to determine the prevalence of antibiotic-resistant bacteria and endotoxin in soil after land application of biosolids. Soil was collected over a 15 month period following land application of biosolids, and antibiotic resistance was ascertained using clinically relevant antibiotic concentrations. Ampicillin, cephalothin, ciprofloxacin, and tetracycline resistance were all monitored separately for any changes throughout the 15 month period. Endotoxin soil concentrations were monitored using commercially available endotoxin analysis reagents. Overall, land application of biosolids did not increase the percentage of antibiotic-resistant culturable bacteria above background soil levels. Likewise, land application of biosolids did not significantly increase the concentration of endotoxin in soil. This study determined and established a baseline understanding of the overall effect that land application of biosolids had on the land-applied field with respect to antibiotic-resistant bacterial and endotoxin soil densities.

Ready-to-Eat Shrimp as an International Vehicle of Antibiotic-Resistant Bacteria

The occurrence of antibiotic-resistant bacteria in foods of animal origin is a potential health threat because resistance can be transferred among bacteria, and antibiotic-resistant pathogens may not respond to antibiotic treatments. Thirteen brands of ready-to-eat shrimp representing four countries of origin were obtained from local grocery stores. Total heterotrophic plate counts were determined, and antibiotic-resistant bacteria were isolated. Total heterotrophic colony counts ranged from 3.3 to 5.6 log CFU/g, which was within approved quality limits. A total of 1,564 isolates representing 162 bacterial species were recovered during screening of resistance to 10 antibiotics: ampicillin, ceftriaxone, chloramphenicol, clindamycin, erythromycin, nalidixic acid, streptomycin, tetracycline, trimethoprim, and vancomycin. Six hundred fifty-seven (42%) of the isolates and 131 (81%) of the species had acquired resistance to antibiotics. Numerous resistant human pathogens were isolated, including Escherichia coli, Enterococcus spp., Salmonella, Shigella flexneri, Staphylococcus spp., and Vibrio spp. Nonresistant Yersinia spp. also were isolated. Ready-to-eat shrimp is sold with instructions to thaw the product before serving, which may result in consumer exposure to antibiotic-resistant bacteria. Widespread trade of this product provides an avenue for international dissemination of antibiotic-resistant pathogens.

Antibiotic-resistant Bacteria from Feces of Livestock, Farmyard Manure, and Farmland in Japan—case report—

We examined the distribution of antibiotic-resistant bacteria by analyzing 19 samples of feces of livestock, solid farmyard manure (FYM), soil from arable fields and orchards treated with FYM or not, and forest soils. Bacteria resistant to ampicillin, vancomycin, kanamycin, chloramphenicol, rifampicin, and tetracycline were enumerated by the dilution plate method at a rate of 50 mg l-1. The total numbers of antibiotic-resistant bacteria in swine or poultry feces were the same as or up to eight orders of magnitude lower than the total numbers of culturable bacteria. The occurrence of antibiotic-resistant bacteria in the poultry feces increased with the use of antibiotics as feed additives. The occurrence of antibiotic-resistant bacteria was much lower in FYM samples than fecal samples with some exceptions. Of the soil samples, only that to which solid swine FYM at 40 t ha-1 had been applied yearly for more than 10 years had significantly higher numbers of total and antibiotic-resistant bacteria than the upland soil that had not been treated with FYM. Resistant isolates from fecal samples showed a broad range of multi-drug resistance (MDR), but those from forest soil had a narrow-range MDR, suggesting that the use of antibiotics as feed additives influences the occurrence of broad-range MDR.

Monitoring of antibiotic resistance in bacteria of animal origin: epidemiological and microbiological methodologies

The occurrence of antibiotic-resistant bacteria in food animals is a major public health threat. Information on the prevalence of resistance to specific drugs in both bacterial and animal species together with changes occurring over time, are necessary to understand the magnitude of the problem and to establish baselines for taking action. The aim of this paper is to define the minimum epidemiological and microbiological requirements for establishing a surveillance of antimicrobial resistance in bacteria of animal origin. Surveillance should involve different bacterial species, veterinary pathogens, zoonotic bacteria and commensal bacteria used as indicators. The collected data should be periodically updated and the reports distributed among practising veterinarians and regulatory authorities. These reports would be a useful tool for developing guidelines for the prudent use of antimicrobial agents in veterinary medicine and for action strategies.

Simultaneous occurrence of Vibrio salmonicida and antibiotic‐resistant bacteria in sediments at abandoned aquaculture sites

Abstract. The present authors have examined the survival of the fish pathogenic bacterium Vibrio salmonidda and the occurrence of antibiotic resistant bacteria in sediments from abandoned aquaculture sites. Survival of V. salmonidda was determined by fluorescent monoclonal antibody labelling combined with 4′,6‐diamidino‐2‐phenylindole (DAPI) staining. Using this method, the authors were able to detect V. salmonidda in sediment samples from six out of 12 abandoned fish farm locations. One out of the six positive stations was abandoned in 1982. Vibrio salmonidda was not detected at the three stations not affected by aquaculture (control locations) or in sediment samples taken 200–250m away from aqua‐culture sites. When applying high‐performance liquid chromatography, oxytctracyclinc or furazolidonc residues were not detected in sediment samples from control or abandoned aquaculture sites. Nevertheless, the percentage of bacteria resistant to oxytctracycline was higher in aquaculture sediments, as compared to control sediments. The simultaneous occurrence of fish pathogens and high levels of resistant bacteria in sediments increases the risk of transfer of resistance to the pathogens.

Resistant bacteria in the normal human flora.

The occurrence of antibiotic-resistant bacteria in the normal human flora has been documented by many groups over the last 20 years. These studies are surveyed and the reasons for the occurrence of resistant bacteria in the normal flora are discussed. The need for surveys in the 1980s using modern molecular techniques to characterize mechanisms of resistance is suggested.

Occurrence of Antibiotic Resistant Bacteria in Environmental Wastes

Microbial resistance to antibiotics has been emerging in environmental isolates. This study was carried out from October 2008 to January 2009 to describe the antibiotic susceptibility pattern of the bacteria isolated from sewage sludge, biowaste and bioslurry samples. A total of 49 identified isolates were taken for antibiotic susceptibility test. Amikacin and Gentamicin were the effective antibiotics for the Gram negative bacteria, comparatively Escherichia coli was the most sensitive. Similarly, all isolates of Staphylococcus aureus and Enterococcus spp. were sensitive to Tetracycline and Erythromycin respectively and none of these isolates were resistant to Vancomycin. Out of 13 S. aureus, five (38.5%) were Methicillin resistant Staphylococcus aureus (MRSA). The multidrug resistant (MDR) isolates accounted for 46.9%, the highest percentage of MDR isolates was seen in Pseudomonas aeruginosa (9/12, 75.0%). The proper management of multidrug resistant bacteria present in waste is suggestive for environmental and public health.Key words: Multidrug resistant bacteria, Bio-waste, Sewage sludge, BioslurryDOI: 10.3126/on.v7i1.2563Our Nature (2009) 7:151-157