Virulent and Multi-drug-Resistant Edwardsiella tarda Infection in Oscar Fish: Unveiling the Threat of Mass Mortality and AMR Dissemination. - Related Documents




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549501.0000Virulent and Multi-drug-Resistant Edwardsiella tarda Infection in Oscar Fish: Unveiling the Threat of Mass Mortality and AMR Dissemination. The Oscar fish (Astronotus ocellatus) is among the most commonly domesticated and exported ornamental fish species from Kerala. The ornamental fish industry faces a significant challenge with the emergence of diseases caused by multi-drug-resistant bacteria. In the present study, six isolates were resolved from the diseased Oscar fish showing haemorrhages, necrosis, and loss of pigmentation. After phenotypic and genotypic characterization, the bacteria were identified as Edwardsiella tarda, Klebsiella pneumoniae, Enterococcus faecalis, Escherichia coli, Brevibacillus borstelensis, and Staphylococcus hominis. Experimental challenge studies in healthy Oscar fish showed that E. tarda caused 100% mortality within 240 h with 6.99 × 10(6) CFU/fish as LD(50) and histopathology revealed the typical signs of infection. The pathogen was re-recovered from the moribund fish thereby confirming Koch's postulates. E. tarda was confirmed through the positive amplification of tarda-specific gene and virulence genes viz., etfD and escB were also detected using PCR. Antibiotic susceptibility tests using disc diffusion displayed that the pathogen is multi-drug-resistant towards antibiotics belonging to aminoglycosides, tetracyclines, and quinolones categories with a MAR index of 0.32, which implicated the antibiotic pressure in the farm. Plasmid curing studies showed a paradigm shift in the resistance pattern with MAR index of 0.04, highlighting the resistance genes are plasmid-borne except for the chromosome-borne tetracycline resistance gene (tetA). This study is the first of its kind in detecting mass mortality caused by E. tarda in Oscar fish. Vigilant surveillance and strategic actions are crucial for the precise detection of pathogens and AMR in aquaculture.202438753164
268910.9994Detection and drug resistance profile of Escherichia coli from subclinical mastitis cows and water supply in dairy farms in Saraburi Province, Thailand. Subclinical mastitis is a persistent problem in dairy farms worldwide. Environmental Escherichia coli is the bacterium predominantly responsible for this condition. In Thailand, subclinical mastitis in dairy cows is usually treated with various antibiotics, which could lead to antibiotic resistance in bacteria. E. coli is also a reservoir of many antibiotic resistance genes, which can be conveyed to other bacteria. In this study, the presence of E. coli in milk and water samples was reported, among which enteropathogenic E. coli was predominant, followed by enteroaggregative E. coli and enterohemorrhagic E. coli, which was found only in milk samples. Twenty-one patterns of antibiotic resistance were identified in this study. Ampicillin- and carbenicillin-resistant E. coli was the most common among the bacterial isolates from water samples. Meanwhile, resistance to ampicillin, carbenicillin, and sulfamethoxazole-trimethoprim was the pattern found most commonly in the E. coli from milk samples. Notably, only the E. coli from water samples possessed ESBL phenotype and carried antibiotic resistance genes, bla(TEM) and bla(CMY-2). This indicates that pathogenic E. coli in dairy farms is also exposed to antibiotics and could potentially transfer these genes to other pathogenic bacteria under certain conditions.201728626609
554720.9994Antibiotic Resistant Bacterial Isolates from Captive Green Turtles and In Vitro Sensitivity to Bacteriophages. This study aimed to test multidrug resistant isolates from hospitalised green turtles (Chelonia mydas) and their environment in North Queensland, Australia, for in vitro susceptibility to bacteriophages. Seventy-one Gram-negative bacteria were isolated from green turtle eye swabs and water samples. Broth microdilution tests were used to determine antibiotic susceptibility. All isolates were resistant to at least two antibiotics, with 24% being resistant to seven of the eight antibiotics. Highest resistance rates were detected to enrofloxacin (77%) and ampicillin (69.2%). More than 50% resistance was also found to amoxicillin/clavulanic acid (62.5%), ceftiofur (53.8%), and erythromycin (53.3%). All the enriched phage filtrate mixtures resulted in the lysis of one or more of the multidrug resistant bacteria, including Vibrio harveyi and V. parahaemolyticus. These results indicate that antibiotic resistance is common in Gram-negative bacteria isolated from hospitalised sea turtles and their marine environment in North Queensland, supporting global concern over the rapid evolution of multidrug resistant genes in the environment. Using virulent bacteriophages as antibiotic alternatives would not only be beneficial to turtle health but also prevent further addition of multidrug resistant genes to coastal waters.201729147114
558930.9994Antibiotic resistance spectrums of Escherichia coli and Enterococcus spp. strains against commonly used antimicrobials from commercial meat-rabbit farms in Chengdu City, Southwest China. Antimicrobial resistance (AMR) is commonly associated with the inappropriate use of antibiotics during meat-rabbit production, posing unpredictable risks to rabbit welfare and public health. However, there is limited research on the epidemiological dynamics of antibiotic resistance among bacteria indicators derived from local healthy meat-rabbits. To bridge the knowledge gap between antibiotic use and AMR distribution, a total of 75 Escherichia coli (E. coli) and 210 Enterococcus spp. strains were successfully recovered from fecal samples of healthy meat-rabbits. The results revealed that diverse AMR phenotypes against seven commonly used antimicrobials, including ampicillin (AMP), amoxicillin-clavulanic acid (A/C), doxycycline (DOX), enrofloxacin (ENR), florfenicol (FFC), gentamicin (GEN), and polymycin B (PMB), were observed among most strains of E. coli and Enterococcus spp. in two rabbit farms, although the distribution pattern of antibiotic resistance between young and adult rabbits was similar. Among them, 66 E. coli strains showed resistance against 6 antimicrobials except for PMB. However, 164 Enterococcus spp. strains only exhibited acquired resistance against DOX and GEN. Notably, the DOX-based AMR phenotypes for E. coli and Enterococcus spp. strains were predominant, indicating the existing environmental stress conferred by DOX exposure. The MICs tests suggested elevated level of antibiotic resistance for resistant bacteria. Unexpectedly, all GEN-resistant Enterococcus spp. strains resistant high-level gentamicin (HLGR). By comparison, the blaTEM, tetA, qnrS and floR were highly detected among 35 multi-resistant E. coli strains, and aac[6']-Ie-aph[2']-Ia genes widely spread among the 40 double-resistant Enterococcus spp. strains. Nevertheless, the presence of ARGs were not concordant with the resistant phenotypes for a portion of resistant bacteria. In conclusion, the distribution of AMR and ARGs are prevalent in healthy meat-rabbits, and the therapeutic antimicrobials use in farming practice may promote the antibiotic resistance transmission among indicator bacteria. Therefore, periodic surveillance of antibiotic resistance in geographic locations and supervisory measures for rational antibiotic use are imperative strategies for combating the rising threats posed by antibiotic resistance, as well as maintaining rabbit welfare and public health.202438756516
560140.9994Presence of Staphylococcus spp. carriers of the mecA gene in the nasal cavity of piglets in the nursery phase. The presence of Staphylococcus spp. resistant to methicillin in the nasal cavity of swine has been previously reported. Considering the possible occurrence of bacterial resistance and presence of resistance genes in intensive swine breeding and the known transmissibility and dispersion potential of such genes, this study aimed to investigate the prevalence of resistance to different antibiotics and the presence of the mecA resistance gene in Staphylococcus spp. from piglets recently housed in a nursery. For this, 60 nasal swabs were collected from piglets at the time of their housing in the nursery, and then Staphylococcus spp. were isolated and identified in coagulase-positive (CoPS) and coagulase-negative (CoNS) isolates. These isolates were subjected to the disk-diffusion test to evaluate the bacterial resistance profile and then subjected to molecular identification of Staphylococcus aureus and analyses of the mecA gene through polymerase chain reaction. Of the 60 samples collected, 60 Staphylococcus spp. were isolated, of which 38 (63.33%) were classified as CoNS and 22 (36.67%) as CoPS. Of these, ten (45.45%) were identified as Staphylococcus aureus. The resistance profile of these isolates showed high resistance to different antibiotics, with 100% of the isolates resistant to chloramphenicol, clindamycin, and erythromycin, 98.33% resistant to doxycycline, 95% resistant to oxacillin, and 85% resistant to cefoxitin. Regarding the mecA gene, 27 (45%) samples were positive for the presence of this gene, and three (11.11%) were phenotypically sensitive to oxacillin and cefoxitin. This finding highlights the importance of researching the phenotypic profile of resistance to different antimicrobials and resistance genes in the different phases of pig rearing to identify the real risk of these isolates from a One Health perspective. The present study revealed the presence of samples resistant to different antibiotics in recently weaned production animal that had not been markedly exposed to antimicrobials as growth promoters or even as prophylactics. This information highlights the need for more research on the possible sharing of bacteria between sows and piglets, the environmental pressure within production environments, and the exposure of handlers during their transport, especially considering the community, hospital, and political importance of the presence of circulating resistant strains.202336634542
288150.9994Comparative analysis of virulence genes, antibiotic resistance and gyrB-based phylogeny of motile Aeromonas species isolates from Nile tilapia and domestic fowl. The nucleotide sequence analysis of the gyrB gene indicated that the fish Aeromonas spp. isolates could be identified as Aeromonas hydrophila and Aeromonas veronii biovar sobria, whereas chicken Aeromonas spp. isolates identified as Aeromonas caviae. PCR data revealed the presence of Lip, Ser, Aer, ACT and CAI genes in fish Aer. hydrophila isolates, ACT, CAI and Aer genes in fish Aer. veronii bv sobria isolates and Ser and CAI genes in chicken Aer. caviae isolates. All chicken isolates showed variable resistance against all 12 tested antibiotic discs except for cefotaxime, nitrofurantoin, chloramphenicol and ciprofloxacin, only one isolate showed resistance to chloramphenicol and ciprofloxacin. Fish Aeromonads were sensitive to all tested antibiotic discs except amoxicillin, ampicillin-sulbactam and streptomycin. SIGNIFICANCE AND IMPACT OF THE STUDY: Many integrated fish farms depend on the application of poultry droppings/litter which served as a direct feed for the fish and also acted as pond fertilizers. The application of untreated poultry manure exerts an additional pressure on the microbial world of the fish's environment. Aeromonas species are one of the common bacteria that infect both fish and chicken. The aim of this study was to compare the phenotypic traits and genetic relatedness of aeromonads isolated from two diverse hosts (terrestrial and aquatic), and to investigate if untreated manure possibly enhances Aeromonas dissemination among cohabitant fish with special reference to virulence genes and antibiotic resistant traits.201526280543
284960.9994Antibiotic-resistant bacteria and gut microbiome communities associated with wild-caught shrimp from the United States versus imported farm-raised retail shrimp. In the United States, farm-raised shrimp accounts for ~ 80% of the market share. Farmed shrimp are cultivated as monoculture and are susceptible to infections. The aquaculture industry is dependent on the application of antibiotics for disease prevention, resulting in the selection of antibiotic-resistant bacteria. We aimed to characterize the prevalence of antibiotic-resistant bacteria and gut microbiome communities in commercially available shrimp. Thirty-one raw and cooked shrimp samples were purchased from supermarkets in Florida and Georgia (U.S.) between March-September 2019. The samples were processed for the isolation of antibiotic-resistant bacteria, and isolates were characterized using an array of molecular and antibiotic susceptibility tests. Aerobic plate counts of the cooked samples (n = 13) varied from < 25 to 6.2 log CFU/g. Isolates obtained (n = 110) were spread across 18 genera, comprised of coliforms and opportunistic pathogens. Interestingly, isolates from cooked shrimp showed higher resistance towards chloramphenicol (18.6%) and tetracycline (20%), while those from raw shrimp exhibited low levels of resistance towards nalidixic acid (10%) and tetracycline (8.2%). Compared to wild-caught shrimp, the imported farm-raised shrimp harbored distinct gut microbiota communities and a higher prevalence of antibiotic-resistance genes in their gut. The presence of antibiotic-resistant strains in cooked shrimps calls for change in processing for their mitigation.202133558614
555870.9994Respiratory microbiota of healthy broilers can act as reservoirs for multidrug-resistant Escherichia coli. This study aimed at evaluate the presence and to study characteristics of Escherichia coli in the respiratory system microbiota of healthy broilers. Trachea, air sacs, and lungs of 20 broilers were analyzed at 21 days of age, reared in experimental conditions, without receiving antimicrobials. E. coli strains were isolated and identified using conventional bacteriology through morphological and biochemical characterization. The production of bacteriocin-like substances, the presence of virulence-associated genes (VAGs) of APEC (Avian Pathogenic Escherichia coli) predictors, and the antimicrobial susceptibility were evaluated. E. coli was found in 85 % of the animals (17/20), in the trachea, air sacs or lungs; and it was not found in 15 % of the animals (3/20). A total of 34 isolates were recovered, 13 from the air sacs, 13 from the lungs, and 8 from the trachea, which showed no production of bacteriocin-like substances nor virulence genes associated with APEC. Most isolates, 59 % (20/34), showed resistance to at least one of the tested antimicrobials, and six multiresistant strains were identified. The results demonstrated that strains of E. coli were commensal of the respiratory microbiota, and that they did not present pathogenicity to the host, since there were no clinical signs of disease, macroscopic lesions in the organs of the evaluated broilers, production of bacteriocin-like substances, nor virulence-associated genes considered as predictors of APEC in bacteria. These strains of E. coli were mostly susceptible to antimicrobials. However, the occurrence of multidrug-resistant strains suggests that these animals can act as reservoirs of resistant to antimicrobials E. coli.202134507109
555280.9994Plasmid-Mediated Fluoroquinolone Resistance Genes in Quinolone-Susceptible Aeromonas spp. Phenotypes Isolated From Recreational Surface Freshwater Reservoir. Aeromonas spp. are recognized as opportunistic pathogens causing diseases. Infections in humans can result mainly in gastrointestinal and wound diseases with or without progression to septicemia. Although Aeromonas spp. are not known uropathogens and they rarely cause urinary tract infection, we hypothesize that the presence of these bacteria in the water and the contact during, e.g., recreational and bathing activity can create the conditions for the colonization of the human body and may result to diseases in various locations, including the urinary tract. Our study presents the occurrence of aeromonad fluoroquinolone-susceptible phenotypes with the presence of plasmid-mediated fluoroquinolone resistance (PMQR) genes in a natural freshwater reservoir occasionally used for recreational activities. Sixty-nine isolates collected during the bathing period were identified by mass spectrometry and screened for the presence of fluoroquinolone-resistant phenotypes and genotypes. Fluoroquinolone susceptibility was determined as minimal inhibitory concentration values. PMQR qnr genes were detected by PCR. Isolates comprising eight species, namely, mainly Aeromonas veronii (50.7% isolates) and Aeromonas media (24.6% isolates) and rarely Aeromonas eucrenophila, Aeromonas caviae, Aeromonas bestiarum, Aeromonas ichthiosmia, and Aeromonas hydrophila, were selected. All isolates were phenotypically susceptible either to ciprofloxacin or levofloxacin. Unexpectedly, at least one to three of the PMQR genes were detected in 42.0% of the fluoroquinolone-susceptible Aeromonas spp. phenotypes. Mainly the qnrS (34.8% isolates) and qnrA (14.5% isolates) determinants were detected. In conclusion, the freshwater reservoir occasionally used for bathing was tainted with aeromonads, with a high occurrence of opportunistic pathogens such as A. veronii and A. media. MALDI-TOF MS is a powerful technique for aeromonad identification. Our data reveals the mismatch phenomenon between fluoroquinolone-susceptible aeromonad phenotypes and the presence of plasmid-mediated qnr resistance genes. It suggests that phenotypically susceptible bacteria might be a potential source for the storage and transmission of these genes. The exposure during, e.g., a recreational activity may create the potential risk for causing infections, both diagnostically and therapeutically difficult, after expressing the resistance genes and quinolone-resistant strain selection.202235646727
196690.9994Identification and characterization of vancomycin-resistant Staphylococcus aureus in hospital wastewaters: evidence of horizontal spread of antimicrobial resistance. Antibiotic resistance has become a major threat to human health around the world, but its spread through the aquatic environment has been often overlooked. This study aimed to determine the occurrence of vancomycin-resistant Staphylococcus aureus in hospital wastewaters and their transmission into public water bodies in Kerala, India. A total of 113 S. aureus were isolated from three hospital effluents in Kerala, India. Standard disc diffusion and the strip method were used for antibiotic susceptibility testing and minimum inhibitory concentration detection. Plasmid-mediated vancomycin resistance was confirmed by plasmid curing and conjugation; resistant genes were detected by the polymerase chain reaction (PCR). Nearly 76% of S. aureus isolates were resistant to β-lactams, chloramphenicol, macrolides, aminoglycosides, and glycopeptide class of antibiotics. Among the vancomycin-resistant Staphylococcus aureus (VRSA) isolates, the prevalence rates of vanA and vanB resistance-encoding genes were 46.5 and 59.3%, respectively. Through the broth mating method, vanA gene was successfully transferred from VRSA donor to vancomycin-sensitive S. aureus. The study strongly indicates the contamination of water bodies with antibiotic-resistant bacteria from hospital discharges, their dissemination and possible transfer to microbes in the aquatic environment, posing a serious threat for public health.202134665771
1925100.9994Camel Milk Resistome in Kuwait: Genotypic and Phenotypic Characterization. Antimicrobial resistance (AMR) is one of the major global health and economic threats. There is growing concern about the emergence of AMR in food and the possibility of transmission of microorganisms possessing antibiotic resistance genes (ARGs) to the human gut microbiome. Shotgun sequencing and in vitro antimicrobial susceptibility testing were used in this study to provide a detailed characterization of the antibiotic resistance profile of bacteria and their ARGs in dromedary camel milk. Eight pooled camel milk samples, representative of multiple camels distributed in the Kuwait desert, were collected from retail stores and analyzed. The genotypic analysis showed the presence of ARGs that mediate resistance to 18 classes of antibiotics in camel milk, with the highest resistance to fluoroquinolones (12.48%) and disinfecting agents and antiseptics (9%). Furthermore, the results pointed out the possible transmission of the ARGs to other bacteria through mobile genetic elements. The in vitro antimicrobial susceptibility testing indicated that 80% of the isolates were resistant to different classes of antibiotics, with the highest resistance observed against three antibiotic classes: penicillin, tetracyclines, and carbapenems. Multidrug-resistant pathogens including Klebsiella pneumoniae, Escherichia coli, and Enterobacter hormaechei were also revealed. These findings emphasize the human health risks related to the handling and consumption of raw camel milk and highlight the necessity of improving the hygienic practices of farms and retail stores to control the prevalence of ARGs and their transmission.202438786109
5586110.9994Antimicrobial Resistance Profile of Common Foodborne Pathogens Recovered from Livestock and Poultry in Bangladesh. Multidrug-resistant (MDR) foodborne pathogens have created a great challenge to the supply and consumption of safe & healthy animal-source foods. The study was conducted to identify the common foodborne pathogens from animal-source foods & by-products with their antimicrobial drug susceptibility and resistance gene profile. The common foodborne pathogens Escherichia coli (E. coli), Salmonella, Streptococcus, Staphylococcus, and Campylobacter species were identified in livestock and poultry food products. The prevalence of foodborne pathogens was found higher in poultry food & by-product compared with livestock (p < 0.05). The antimicrobial drug susceptibility results revealed decreased susceptibility to penicillin, ampicillin, amoxicillin, levofloxacin, ciprofloxacin, tetracycline, neomycin, streptomycin, and sulfamethoxazole-trimethoprim whilst gentamicin was found comparatively more sensitive. Regardless of sources, the overall MDR pattern of E. coli, Salmonella, Staphylococcus, and Streptococcus were found to be 88.33%, 75%, 95%, and 100%, respectively. The genotypic resistance showed a prevalence of blaTEM, blaSHV, blaCMY, tetA, tetB, sul1, aadA1, aac(3)-IV, and ereA resistance genes. The phenotype and genotype resistance patterns of isolated pathogens from livestock and poultry had harmony and good concordance, and sul1 & tetA resistance genes had a higher prevalence. Good agricultural practices along with proper biosecurity may reduce the rampant use of antimicrobial drugs. In addition, proper handling, processing, storage, and transportation of foods may decline the spread of MDR foodborne pathogens in the food chain.202236358208
5555120.9994New sequence types and multidrug resistance among pathogenic Escherichia coli isolates from coastal marine sediments. The spread of antibiotic-resistant microorganisms is widely recognized, but data about their sources, presence, and significance in marine environments are still limited. We examined 109 Escherichia coli strains from coastal marine sediments carrying virulence genes for antibiotic susceptibility, specific resistance genes, prevalence of class 1 and 2 integrons, and sequence type. Antibiotic resistance was found in 35% of strains, and multiple resistances were found in 14%; the resistances detected most frequently were against tetracycline (28%), ampicillin (16.5%), trimethoprim-sulfamethoxazole (13%), and streptomycin (7%). The highest prevalence of resistant strains was in phylogenetic group A, whereas phylogroup B2 exhibited a significantly lower frequency than all the other groups. Sixty percent of multiresistant strains harbored class 1 or 2 integrase genes, and about 50% carried resistance genes (particularly dfrA and aadA) linked to a class 1 integron. Multilocus sequence typing of 14 selected strains identified eight different types characteristic of extraintestinal pathogens and three new allelic combinations. Our data suggest that coastal marine sediment may be a suitable environment for the survival of pathogenic and antimicrobial-resistant E. coli strains capable of contributing to resistance spread via integrons among benthic bacteria, and they highlight a role for these strains in the emergence of new virulent genotypes.201222447595
1965130.9994Phenotypic Investigation of Florfenicol Resistance and Molecular Detection of floR Gene in Canine and Feline MDR Enterobacterales. Florfenicol is a promising antibiotic for use in companion animals, especially as an alternative agent for infections caused by MDR bacteria. However, the emergence of resistant strains could hinder this potential. In this study, florfenicol resistance was investigated in a total of 246 MDR Enterobacterales obtained from canine and feline clinical samples in Greece over a two-year period (October 2020 to December 2022); a total of 44 (17,9%) florfenicol-resistant strains were recognized and further investigated. Most of these isolates originated from urine (41.9%) and soft tissue (37.2%) samples; E. coli (n = 14) and Enterobacter cloacae (n = 12) were the predominant species. The strains were examined for the presence of specific florfenicol-related resistance genes floR and cfr. In the majority of the isolates (31/44, 70.5%), the floR gene was detected, whereas none carried cfr. This finding creates concerns of co-acquisition of plasmid-mediated florfenicol-specific ARGs through horizontal transfer, along with several other resistance genes. The florfenicol resistance rates in MDR isolates seem relatively low but considerable for a second-line antibiotic; thus, in order to evaluate the potential of florfenicol to constitute an alternative antibiotic in companion animals, continuous monitoring of antibiotic resistance profiles is needed in order to investigate the distribution of florfenicol resistance under pressure of administration of commonly used agents.202438393089
5545140.9994Healthy broilers disseminate antibiotic resistance in response to tetracycline input in feed concentrates. Wide varieties of antibiotics are used in poultry farms to improve the growth and also to control the infection in broiler chicken. To identify the seriousness of the same in the poultry sector, current study has been designed to analyze the presence of tetracycline in poultry feed and also the tetracycline resistance among the bacteria released through the excreta of poultry. In the study, 27 bacteria belonging to the Escherichiacoli and Klebsiellapneumoniae. were isolated from the faecal samples collected from five different farms. Antibiotic susceptibility analysis showed 77% of E. coli and 100% of the K. pneumoniae. to be resistant to tetracycline. Further, molecular screening for tetA and tetB genes showed 85.18% of isolates to have tetA and 22.22% with tetB. The presence of tetracycline in collected feed samples was also analysed quantitatively by Liquid chromatography-mass spectrometry (LC-MS). Here, three out of five feed samples were found to be positive for tetracycline. The study showed a direct correlation between the antibiotic supplemented feed and the emergence of antimicrobial resistance among the intestinal microflora. The results of the study indicate the need for strict control over antibiotic use in animal feed to limit the rapid evolution and spread of antimicrobial resistance.202033039593
5542150.9994Analysis of bacteriological pollution and the detection of antibiotic resistance genes of prevailing bacteria emanating from pig farm seepage. Management and disposal of pig farm seepage constitute a serious environmental challenge, and seepage discharge from agricultural waste-water is considered to be one of the greatest contributors of organic substances, bacterial pathogens, and antibiotic resistance genes into the environment. The objectives of this study were to assess the level of bacteriological pollution and to identify the resident antibiotic-resistant genes of culturable bacteria from a studied pig farm seepage. Enumeration of the viable bacterial cell of plated bacteria suspensions (10(-1) to 10(-8)  cfu/mL) was performed; also, identification of pure bacterial colonies was done using an API 20E bacterial identification kit. CLSI guidelines for antimicrobial susceptibility testing were adopted to determine the antibiotic susceptibility/resistance of the cultured bacterial isolates. Identification of resident-resistant genes was done using molecular biology procedures. The results on viable cells in seepage samples ranged from 4.30 × 10(2) to 1.29 × 10(9 ) cfu/mL. Pseudomonas luteola, Enterococcus vulneris, Salmonella choleraesuis spp arizonae, Escherichia coli, Enterobacter cloacae, Proteus mirabillis etc. were isolated from the pig farm soil samples. Almost all of the cultured isolates were resistant to Penicillin G, Vancomycin, Oxytetracycline, Spectinomycin, and Lincomycin. The most frequent resistant genes detected in the isolates were Van A, Van B, InuA, aph (3")-llla, bla(TEM,) Otr A, and Otr B. It was inferred from the study that Pig farm seepage has the ability to cause bacterial pollution that may negatively impact the natural environment, by introducing bacteria pathogens that harbor antibiotic-resistant genes.201930414264
5536160.9994Phenotypic and genetic characterization of multidrug-resistant Staphylococcus aureus in the tropics of Southeast Asia. Antibiotic resistance has become a major public health problem throughout the world. The presence of antibiotic-resistant bacteria such as Staphylococcus aureus and antibiotic resistance genes (ARGs) in hospital wastewater is a cause for great concern today. In this study, 276 Staph. aureus isolates were recovered from hospital wastewater samples in Malaysia. All of the isolates were screened for susceptibility to nine different classes of antibiotics: ampicillin, ciprofloxacin, gentamicin, kanamycin, erythromycin, vancomycin, trimethoprim and sulfamethoxazole, chloramphenicol, tetracycline and nalidixic acid. Screening tests showed that 100 % of Staph.aureus isolates exhibited resistance against kanamycin, vancomycin, trimethoprim and sulfamethoxazole and nalidixic acid. Additionally, 91, 87, 50, 43, 11 and 8.7 % of isolates showed resistance against erythromycin, gentamicin, ciprofloxacin, ampicillin, chloramphenicol and tetracycline, respectively. Based on these results, 100 % of isolates demonstrated multidrug-resistant (MDR) characteristics, displaying resistance against more than three classes of antibiotics. Of 276 isolates, nine exhibited resistance to more than nine classes of tested antibiotics; these were selected for antibiotic susceptibility testing and examined for the presence of conserved ARGs. Interestingly, a high percentage of the selected MDR Staph.aureus isolates did not contain conserved ARGs. These results indicate that non-conserved MDR gene elements may have already spread into the environment in the tropics of Southeast Asia, and unique resistance mechanisms against several antibiotics may have evolved due to stable, moderate temperatures that support growth of bacteria throughout the year.201627902427
2817170.9994Characterization of antibiotic resistant enterococci isolated from untreated waters for human consumption in Portugal. Untreated drinking water is frequently overlooked as a source of antibiotic resistance in developed countries. To gain further insight on this topic, we isolated the indicator bacteria Enterococcus spp. from water samples collected in wells, fountains and natural springs supplying different communities across Portugal, and characterized their antibiotic resistance profile with both phenotypic and genetic approaches. We found various rates of resistance to seven antibiotic families. Over 50% of the isolates were resistant to at least ciprofloxacin, tetracyclines or quinupristin-dalfopristin and 57% were multidrug resistant to ≥3 antibiotics from different families. Multiple enterococcal species (E. faecalis, E. faecium, E. hirae, E. casseliflavus and other Enterococcus spp) from different water samples harbored genes encoding resistance to tetracyclines, erythromycin or gentamicin [tet(M)-46%, tet(L)-14%, tet(S)-5%, erm(B)-22%, aac(6´)-Ie-aph(2″)-12%] and putative virulence factors [gel-28%, asa1-16%]. The present study positions untreated drinking water within the spectrum of ecological niches that may be reservoirs of or vehicles for antibiotic resistant enterococci/genes. These findings are worthy of attention as spread of antibiotic resistant enterococci to humans and animals through water ingestion cannot be dismissed.201121145609
2885180.9994Antimicrobial susceptibility of Streptococcus gallolyticus isolated from humans and animals. Susceptibilities to some antimicrobial agents and distribution of genes associated with resistance were examined in a total of 66 Streptococcus gallolyticus isolates and reference strains from various sources. All the tested bacteria were susceptible to vancomycin, penicillin G, and ampicillin. Most of the erythromycin-resistant isolates were observed in human clinical samples. Tetracycline and doxycycline resistance was prevalent in the isolates from human patients, diseased animals, and healthy broiler chickens, while the prevalence was significantly lower in the isolates from healthy mammals. All the isolates resistant to tetracycline possessed tet(M) and/or tet(L) and/or tet(O) genes. However, most isolates from healthy animals, which were susceptible to tetracycline, possessed the above-cited resistance genes, implying the potential ability for resistance under exposure to the corresponding antimicrobial agents.201323883848
5602190.9994Molecular characterization of the virulent microorganisms along with their drug-resistance traits associated with the export quality frozen shrimps in Bangladesh. Current investigation characterized export quality shrimp samples in terms of pathogenic load along with the drug-resistance traits of the isolates, and detected the major virulent genes present in those isolates. Among the 30 such shrimp samples (15 each of Macrobrachium rosenbergi or Golda and Penaeus monodon or Bagda) studied, almost all were found to be contaminated with a huge load of bacteria (10(6)-10(8) cfu/g) and fungi (10(4)-10(5) cfu/g). Among the specific pathogens, presence of Escherichia coli, Vibrio spp., Aeromonas spp., Klebsiella spp., Shigella spp., Staphylococcus spp. and Listeria spp. were detected, of which most were likely to be resistant against commonly used antibiotics. Gene specific polymerase chain reaction (PCR) study revealed the presence of eae gene in E. coli, aero specific gene in Aeromonas spp., and sodB gene in Vibrio spp. Together with the huge extent of microbial contamination with a drug-resistance attribute, presence of such virulent genes further projects the probable public health risk upon consumption of the export quality shrimps.201425197622