# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 5278 | 0 | 1.0000 | Antibiotic resistance of culturable heterotrophic bacteria isolated from shrimp (Penaeus vannamei) aquaculture ponds. Shrimp aquaculture is one of the fastest growing food-producing avenues, where antibiotics usage has become an issue of great concern due to the development of antimicrobial resistance in bacteria. A total of 2304 bacterial isolates from 192 samples (sediment, water, shrimp, and source water) from Andhra Pradesh, India were screened. Antibiotic resistance of bacterial isolates was highest for oxytetracycline (23.4%) followed by erythromycin (12.7%), co-trimoxazole (10%) ciprofloxacin (9.6%), and chloramphenicol (6%), of which 11.9% isolates were multi-drug resistant. Bacterial isolates from shrimp (26.7%), water (23.9%), and sediment (19.6%) samples exhibited more resistance (p ≤ 0.05) towards oxytetracycline. Higher antibacterial resistance was observed from samples of southern Andhra Pradesh (locations L6 and L7). Gram negative bacteria were more prevalent (64%) and showed significantly (p ≤ 0.01) higher resistance. This study indicated the wider distribution of antibiotic-resistant bacteria in shrimp aquaculture ponds with potential risk to humans and the environment. | 2021 | 34450408 |
| 5272 | 1 | 0.9998 | Prevalence of Antibiotic Resistance Genes in Multidrug-Resistant Enterobacteriaceae on Portuguese Livestock Manure. The exposure of both crop fields and humans to antibiotic-resistant bacteria in animal excreta is an emergent concern of the One Health initiative. This study assessed the contamination of livestock manure from poultry, pig, dairy farms and slaughterhouses in Portugal with resistance determinants. The resistance profiles of 331 Enterobacteriaceae isolates to eight β-lactam (amoxicillin, cefoxitin, cefotaxime, cefpirome, aztreonam, ceftazidime, imipenem and meropenem) and to five non-β-lactam antibiotics (tetracycline (TET), trimethoprim/sulfamethoxazole (SXT), ciprofloxacin (CIP), chloramphenicol (CHL) and gentamicin) was investigated. Forty-nine integron and non-β-lactam resistance genes were also screened for. Rates of resistance to the 13 antibiotics ranged from 80.8% to 0.6%. Multidrug resistance (MDR) rates were highest in pig farm samples (79%). Thirty different integron and resistance genes were identified. These were mainly associated with resistance to CHL (catI and catII), CIP (mainly, qnrS, qnrB and oqx), TET (mainly tet(A) and tet(M)) and SXT (mostly dfrIa group and sul3). In MDR isolates, integron presence and non-β-lactam resistance to TET, SXT and CHL were positively correlated. Overall, a high prevalence of MDR Enterobacteriaceae was found in livestock manure. The high gene diversity for antibiotic resistance identified in this study highlights the risk of MDR spread within the environment through manure use. | 2019 | 30871244 |
| 5271 | 2 | 0.9997 | Occurrence of Antibiotic-Resistant Bacteria and Genes in Two Drinking Water Treatment and Distribution Systems in the North-West Province of South Africa. With the increasing spread of antimicrobial resistance, there is growing attention to the contribution made by drinking water systems. The potential health impact of two drinking water treatment and distribution systems (A and B) in the North-West Province of South Africa was determined by investigating the water quality and occurrence of antimicrobial-resistant heterotrophic bacteria and genes in the raw and treated water over four seasons. Most of the physicochemical parameters except for electrical conductivity were within permissible limits. Coliform bacteria reduced from raw to potable water except for counts higher than the threshold recorded in Summer and Winter. A total of 203 heterotrophic bacterial isolates were recovered on chromogenic R2A medium and subjected to susceptibility testing to twelve antibiotics. Most of the isolates were resistant to β-lactam antibiotics and Trimethoprim, whereas they were susceptible to Ciprofloxacin, Erythromycin, and Neomycin. The proportions of Cephalothin and Kanamycin-resistant isolates were significantly higher (p < 0.05) after treatment for site A, compared to significantly lower β-lactam, Oxytetracycline, and Trimethoprim-resistant isolates for B. Over 50% of isolates were of high risk, indicating their origin from high antibiotic-use sources. Seventy-one (35%) isolates were multidrug-resistant, out of which the majority (53.5%, n = 38) possessed the strA gene, followed by strB 21 (29.6%), dfrB 13 (18.3%), aadA 11 (15.5%), bla(CTX-M) 5 (7.0%), and tetA 3 (4.2%). The 16S rRNA gene sequences of the isolates revealed strains belonging to eight bacterial families, some of which are clinically important. | 2020 | 33126462 |
| 5258 | 3 | 0.9997 | Occurrence of seventeen veterinary antibiotics and resistant bacterias in manure-fertilized vegetable farm soil in four provinces of China. This study focused on the occurrence of seventeen veterinary antibiotics and six resistant bacterias in soils from the vegetable farms fertilized with animal manure in China. Seventeen veterinary antibiotics, including sulfonamides, quinolones, tetracyclines, macrolides and amphenicols, were detected by high performance liquid chromatography/tandem mass spectrometer in all the 53 soil samples collected in four provinces during August 2016. The concentrations of target antibiotics in the soil samples ranged from not detectable to 415.00 μg/kg dry weight with the mean residual levels of the five classes followed order: tetracyclines (82.75 μg/kg) > quinolones (12.78 μg/kg) > macrolides (12.24 μg/kg) > sulfonamides (2.61 μg/kg) > amphenicols (0.06 μg/kg). Moreover, the highest antibiotic levels were found mainly in soil from organic vegetable farms. Risk assessment by using the methods of risk quotient, suggested that oxytetracycline, chlortetracycline, enrofloxacin and ciprofloxacin could pose severe ecological risk in sampled soils. Resistant strains were isolated in 30 samples, with Escherichia coli and Klebsiella pneumonia found the dominant bacterial hosts with resistance genes. Antibiotic resistance genes, including tetA, tetB, qnrS, oqxA, sul1, sul2, ermA and floR, were detected in the strains resistant to: tetracyclines, quinolones, sulfonamides, macrolides and amphenicols resistance, respectively. Overall, there was a correlation between the results of antibiotic risk assessment with the detection of resistance genes from isolated strains in the soils. | 2019 | 30317094 |
| 5269 | 4 | 0.9997 | Prevalence of antibiotic resistance genes in bacteria from Gomti and Ganga rivers: implications for water quality and public health. Rivers serve as a significant habitat and water sources for diverse organisms, including humans. An important environmental and public health concern is the increase in antibiotic-resistant bacteria (ARBs) and genes (ARGs) in aquatic ecosystems brought about by excessive pollutant flow. The research highlighted that river water, which is receiving discharge from wastewater treatment plants, is harbouring multidrug-resistant bacteria. River water samples were collected in January, April, July and October 2022 from three separate locations of each Gomti and Ganga river. A total of 114 bacteria were isolated from Gomti as well as the Ganga River. All the isolates were tested for their resistance to various antibiotics by disc diffusion method. The isolated bacteria were tested for the antibiotic resistance genes using PCR and were identified by 16s rRNA sequencing. The ARBs percentages for each antibiotic were as follows: ampicillin (100%); cefotaxime (96.4, 63.1%); erythromycin (52.6, 57.8%); amikacin (68.4, 50.8%); tetracycline (47.3, 54.3%); nalidixic acid (47.3, 45.6%); streptomycin (68.4, 49.1%); gentamycin (43.8, 35%); chloramphenicol (26.3, 33.3%); neomycin (49.1, 29.8%) and ciprofloxacin (24.5, 7.01%). Further, antibiotic resistance genes in Gomti and Ganga water samples disclose distinctive patterns, including resistance to ermB (25, 40%); tetM (25, 33.3%); ampC (44.4, 40%) and cmlA1 (16.6%). Notably cmlA1 resistant genes were absent in all bacterial strains of the Gomti River. Additionally, gyrA gene was not found in both the river water samples. The presence of ARGs in the bacteria from river water shows threat of transferring these genes to native environmental bacteria. To protect the environment and public health, constant research is necessary to fully understand the extent and consequences of antibiotic resistance in these aquatic habitats. | 2024 | 39349711 |
| 1359 | 5 | 0.9997 | Assessment of Bacterial Contamination and Antimicrobial Resistance of Escherichia coli Isolates from Slovak Dairy Farms. The conditions in livestock housing are suitable for the survival of airborne microorganisms, mainly due to high temperatures, humidity, and the presence of organic material. The total count of airborne bacteria concentrations in cattle farms ranged from 3.01 log(10) CFU/mL to 6.90 log(10) CFU/mL; for coliform bacteria, they were from 2.18 log(10) CFU/mL to 3.34 log(10) CFU/mL; and for molds, they ranged from 3.00 log(10) CFU/mL to 4.57 log(10) CFU/mL. Bacteria resistant to antimicrobial substances and resistance genes can be spread on animal farms. Antimicrobial resistance in ubiquitous Escherichia coli isolated from cattle feces was investigated. Minimum inhibitory concentration (MIC) testing was utilized to identify phenotypic resistance profiles, and the PCR method was employed to detect the presence of resistant genes. A higher percentage of resistance was found to amikacin (65%), tetracycline (61%), streptomycin (56%), ampicillin (55%), and nalidixic acid (45%). Multidrug resistance was determined in up to 64.3% of the isolates studied. The most widespread resistance genes were bla(TEM) (85.7%), sul2 (66.7%), tetB (52.38%), and sul1 (47.6%). We found that 4.8% of the E. coli isolates had the bla(CMY) gene. We found that, despite phenotypic resistance, E. coli isolates do not necessarily carry genes conferring resistance to that particular antimicrobial agent. | 2024 | 39518818 |
| 1362 | 6 | 0.9997 | Distribution of phenotypic and genotypic antimicrobial resistance and virulence genes in Vibrio parahaemolyticus isolated from cultivated oysters and estuarine water. A total of 594 Vibrio parahaemolyticus isolates from cultivated oysters (n = 361) and estuarine water (n = 233) were examined for antimicrobial resistance (AMR) phenotype and genotype and virulence genes. Four hundred forty isolates (74.1%) exhibited resistance to at least one antimicrobial agent and 13.5% of the isolates were multidrug-resistant strains. Most of the V. parahaemolyticus isolates were resistant to erythromycin (54.2%), followed by sulfamethoxazole (34.7%) and trimethoprim (27.9%). The most common resistance genes were qnr (77.8%), strB (27.4%) and tet(A) (22.1%), whereas blaTEM (0.8%) was rarely found. Four isolates (0.7%) from oysters (n = 2) and estuarine water (n = 2) were positive to tdh, whereas no trh-positive isolates were observed. Significantly positive associations among AMR genes were observed. The SXT elements and class 1, 2 and 3 integrons were absent in all isolates. The results indicated that V. parahaemolyticus isolates from oysters and estuarine water were potential reservoirs of resistance determinants in the environment. This increasing threat of resistant bacteria in the environment potentially affects human health. A 'One Health' approach involved in multidisciplinary collaborations must be implemented to effectively manage antimicrobial resistance. | 2020 | 32358958 |
| 2860 | 7 | 0.9997 | Multi-drug resistance, integron and transposon-mediated gene transfer in heterotrophic bacteria from Penaeus vannamei and its culture environment. Multi-drug resistance (MDR) in bacteria is regarded as an emerging pollutant in different food production avenues including aquaculture. One hundred and sixty out of 2304 bacterial isolates from shrimp farm samples (n = 192) of Andhra Pradesh, India, were MDR. Based on biochemical identification and 16S rRNA sequencing, they were grouped into 35 bacterial species with the predominance of Vibrio parahaemolyticus (12.5%). The MDR isolates showed highest resistance toward oxytetracycline (89%) with more than 0.2 MAR (multiple antibiotic resistance), demonstrates a high-risk source. The most prevalent antibiotic-resistance gene (ARG) and mobile genetic element (MGE) detected were tetA (47.5%) and int1 (46.2%), respectively. In conjugation experiments, overall transfer frequency was found to be in the range of 1.1 × 10(-9) to 1.8 × 10(-3) with the transconjugants harbouring ARGs and MGEs. This study exposed the wide distribution of MDR bacteria in shrimp and its environment, which can further aggravate the already raised concerns of antibiotic residues in the absence of proper mitigation measures. | 2022 | 35066837 |
| 5270 | 8 | 0.9997 | Environmental antibiotic stress and high-risk resistance genes in bacterial communities of the Gomti and Ganga Rivers, India. BACKGROUND: The river ecosystems provide habitats and source of water for a number of species including humans. The uncontrolled accumulation of pollutants in the aquatic environment enhances the development of antibiotic-resistant bacteria and genes. METHODS: Water samples were collected seasonally from different sites of Gomti and Ganga River. Bacteria were isolated by plating on nutrient agar supplemented with individual antibiotics (100 µg/ml) to select the resistant strains. These isolates were subsequently tested for cross-resistance to other antibiotics using the disc diffusion method. PCR was performed to detect selected ARGs. RESULTS: The enumeration of microbial population of Gomti River, the tetracycline-resistant bacteria comprised 38% of the bacterial population during spring and chloramphenicol resistance during autumn was a mere 11.9%. Nevertheless, erythromycin resistance was widespread amongst Ganga river bacteria during winter by 28%, while ciprofloxacin resistance was seen in autumn with only 15.8%. Bacterial population led to decline due to antibiotic-induced stress. The tetracycline-resistant bacteria were completely resistant to ampicillin and 66.6% were resistant to erythromycin. In Ganga river water, 53.5% of ampicillin-resistant isolates were resistant to erythromycin and sulphadiazine 93.3% were resistant to nalidixic acid. In the Gomti River water, the most common resistance gene among tetracycline resistant isolates was tetM (83.3%), followed by ampC (83.3%) in ampicillin-resistant isolates. In the Ganga River, 66.6% of bacterial isolates were found to have ampC and ermB genes. The sul1 gene was absent in all the bacterial isolates in both water samples. CONCLUSION: These findings indicate that both rivers act as reservoirs for multidrug-resistant bacteria harbouring complex resistance gene profiles. | 2025 | 40928717 |
| 2848 | 9 | 0.9997 | Antimicrobial Resistant Bacteria Monitoring in Raw Seafood Retailed: a Pilot Study Focused on Vibrio and Aeromonas. In aquaculture, bacterial infections in sea animals are treated using antimicrobials. As seafood is frequently consumed in its raw form, seafood contaminated with water-borne antimicrobial-resistant bacteria presents a potential transmission route to humans and can influence food safety. In this study, we aimed to determine the abundance of water-borne bacteria in retail raw seafood and to characterize their antimicrobial resistance profiles. In total, 85 retail raw seafood samples (32 fish, 26 shellfish, 25 mollusks, and two crustaceans) were purchased from supermarkets in Japan, and water-borne bacteria were isolated. The isolated bacterial species predominantly included Vibrio spp. (54.1%) and Aeromonas spp. (34.1%). Vibrio or Aeromonas spp. were isolated from more than 70% of the seafood samples. Tetracycline-, sulfamethoxazole-, and/or trimethoprim/sulfamethoxazole-resistant Vibrio or Aeromonas spp. isolates were detected in seven (21.9%) fish samples (two wild-caught and five farm-raised) harboring tet, sul, and/or dfr genes. Sulfamethoxazole- and trimethoprim/sulfamethoxazole-resistant isolates were only detected in farm-raised fish. Tetracycline and sulfamethoxazole are commonly used in aquaculture. These results suggest that water-borne bacteria like Vibrio and Aeromonas spp. should be the primary focus of antimicrobial-resistant bacteria monitoring to effectively elucidate their spread of bacteria via seafood. | 2023 | 38144894 |
| 2888 | 10 | 0.9997 | AMR Threat Perception Assessment of Heterotrophic Bacteria From Shrimp Aquaculture Through Epidemiological Cut off Values. BACKGROUND: Emergence and dissemination of antibiotic resistance is one of the major risks associated with the rampant usage of antibiotics in food-producing animals including aquaculture. OBJECTIVE: To determine Epidemiological Cut-OFF (ECOFF) values of heterotrophic bacterial populations from shrimp culture environments against five different antibiotics. METHODS: In this present study, bacterial samples were isolated from Penaeus vannamei culture environment in different locations of Andhra Pradesh, which is the aquaculture hub of India. The bacterial isolates were assessed for antibiotic resistance towards five antibiotics belonging to different classes (oxytetracycline, chloramphenicol, erythromycin, ciprofloxacin, and co-trimoxazole) by the disc diffusion method. Determination of Epidemiological Cut-OFF (ECOFF) values and analysis by employing normalized resistance interpretation (NRI) was carried out. RESULTS: The most dominant bacterial populations from shrimp culture were Vibrio spp. (pathogenic bacteria) followed by Bacillus spp. (probiotic bacteria). The bacterial isolates showed highest resistance towards oxytetracycline (overall 23.38%) and in location L6 (59.4%) followed by co-trimoxazole (31.1%). ECOFF values calculated by employing NRI showed that the disc diffusion data were distributed in a normalized manner. The maximum ECOFF value was obtained for ciprofloxacin (23.32 mm), while the minimum value was observed for oxytetracycline (9.05 mm). The antibiotic resistant phenotypes showed that the majority of the heterotrophic bacterial isolates (>60%) belonged to the non-wild type phenotype and primarily towards oxytetracycline (90%). CONCLUSION: The presence of non-wild antibiotic-resistant phenotypes of heterotrophic bacterial populations (which include not only pathogenic bacteria but also probiotic bacteria) indicates that shrimp culture ponds may be a reservoir for drug-resistant bacteria and there is a greater risk associated with transmission of resistant genes across bacterial flora. HIGHLIGHTS: NRI analysis of antibiotic disc diffusion data of heterotrophic bacterial populations in shrimp aquaculture environments revealed that majority of them belonged to non-wild type (90%) paticularly to oxytetracycline in comparison to other studied antibiotics (chloramphenicol, erythromycin, ciprofloxacin and co-trimoxazole). | 2024 | 38366611 |
| 5277 | 11 | 0.9996 | Antibiotic resistance of bacteria isolated from shrimp hatcheries and cultural ponds on Donghai Island, China. The resistance of bacteria to 12 different antibiotics was investigated in shrimp farms on Donghai Island, China. Antibiotic-resistant bacteria were found to be widespread in shrimp farms, indicating a high environmental risk. Further, significant differences were found in bacterial strains among farms (ANOVA, p<0.05), showing resistance to antibiotics such as ampicillin, trimethoprim, compound sinomi, tetracycline, chloramphenicol and cefazolin. No significant differences in antibiotic resistance were found among 6 hatcheries evaluated in this study (ANOVA, p>0.05), between exalted and traditional shrimp ponds (ANOVA, p>0.05), and between cultural ponds and corresponding control water source sites (T-test, p>0.05). In cultural ponds, no significant difference in bacterial resistance to antibiotics was found between water and sediment (T-test, p>0.05), and antibiotic resistance of bacteria from water showed a significant positive correlation with that from sediment (p<0.05). Therefore, our study indicates that bacterial multiple antibiotic resistance (MAR) is more widespread in shrimp hatcheries than ponds. | 2011 | 21945557 |
| 2931 | 12 | 0.9996 | Molecular characterization of antibiotic resistance in Escherichia coli strains from a dairy cattle farm and its surroundings. BACKGROUND: This study describes the phenotypic and genotypic characteristics of 78 genetically different Escherichia coli recovered from air and exudate samples of a dairy cattle farm and its surroundings in Spain, in order to gain insight into the flow of antimicrobial resistance through the environment and food supply. RESULTS: Antimicrobial resistance was detected in 21.8% of the 78 E. coli isolates analyzed (resistance for at least one of the 14 agents tested). The highest resistance rates were recorded for ampicillin, nalidixic acid, trimethoprim/sulfamethoxazole and tetracycline. The resistance genes detected were as follows (antibiotic (number of resistant strains), gene (number of strains)): ampicillin (9), bla(TEM-1) (6); tetracycline (15), tet(A) (7), tet(B) (4), tet(A) + tet(B) (1); chloramphenicol (5), cmlA (2), floR (2); trimethoprim/sulfamethoxazole (10), sul2 (4), sul1 (3), sul3 (2), sul1 + sul2 (1); gentamicin-tobramycin (1), ant(2″) (1). About 14% of strains showed a multidrug-resistant phenotype and, of them, seven strains carried class 1 integrons containing predominantly the dfrA1-aadA1 array. One multidrug-resistant strain was found in both inside and outside air, suggesting that the airborne spread of multidrug-resistant bacteria from the animal housing facilities to the surroundings is feasible. CONCLUSIONS: This study gives a genetic background of the antimicrobial resistance problem in a dairy cattle farm and shows that air can act as a source for dissemination of antimicrobial-resistant bacteria. © 2016 Society of Chemical Industry. | 2017 | 26969806 |
| 1363 | 13 | 0.9996 | Comparison of antimicrobial resistance and molecular characterization of Escherichia coli isolates from layer breeder farms in Korea. In Korea, 4 big layer companies that possess one grandparent and 3 parent stocks are in charge of 100% of the layer chicken industry. In this study, we investigated the antimicrobial resistance of commensal 578 E. coli isolated from 20 flocks of 4-layer breeder farms (A, B, C, and D), moreover, compared the characteristics of their resistance and virulence genes. Isolates from farms B and D showed significantly higher resistance to the β-lactam antimicrobials (amoxicillin, ampicillin, and 1st-, 2nd-, and 3rd-generation cephalosporins). However, resistance to ciprofloxacin, nalidixic acid, and tetracycline was significantly higher in the isolates from farm A (P < 0.05). Interestingly, the isolates from farm C showed significantly lower resistance to most antimicrobials tested in this study. The isolates from farms B, C, and D showed the high multiple resistance to the 3 antimicrobial classes. Furthermore, the isolates from farm A showed the highest multiple resistance against the 5 classes. Among the 412 β-lactam-resistant isolates, 123 (29.9%) carried bla(TEM-1), but the distribution was significantly different among the farms from 17.5% to 51.4% (P < 0.05). Similarly, the most prevalent tetracycline resistance gene in the isolates from farms B, C, and D was tetA (50.0-77.0%); however, the isolates from farm A showed the highest prevalence in tetB (70.6%). The distribution of quinolone (qnrB, qnrD, and qnrS) and sulfonamide (su12)-resistant genes were also significantly different among the farms but that of chloramphenicol (catA1)- and aminoglycoside (aac [3]-II, and aac [6']-Ib)-resistant genes possessed no significant difference among the farms. Moreover, the isolates from farm C showed significantly higher prevalence in virulence genes (iroN, ompT, hlyF, and iss) than the other 3 farms (P < 0.05). Furthermore, the phenotypic and genotypic characteristics of E. coli isolates were significantly different among the farms, and improved management protocols are required to control of horizontal and vertical transmission of avian disease, including the dissemination of resistant bacteria in breeder flocks. | 2022 | 34844113 |
| 2847 | 14 | 0.9996 | Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli and Klebsiella isolated from dairy farm milk, farm slurry and water in Punjab, India. Antibiotic resistance is a mushrooming pandemic at national and international levels which if not controlled at this very moment, can lead to global problems. Main reason for emerging bacterial resistance is repeated exposure of bacteria to antimicrobial agents and access of bacteria to increasingly large pools of antimicrobial resistance genes in mixed bacterial populations. A total of 51 villages were sampled in the current study contributing to a total of 153 farms. A total of 612 samples comprising 153 each of raw pooled milk samples, slurry, animal drinking water and human drinking water were gathered from small, medium and large farms located in all seven tehsils of Ludhiana district of Punjab. In addition to that, 37 samples of village pond water were also collected from the targeted villages. Out of total 153 slurry, raw pooled milk samples, animal drinking water and human drinking water samples (each), the prevalence of 24.8%, 60%, 26.7% and 16.3% was found for E. coli respectively. On the other hand, for Klebsiella, the overall prevalence of 19.6%, 51%, 20.2% and 5.8% was found from slurry, raw pooled milk samples, animal drinking water and human drinking water respectively. In all matrices, the comparative frequency of resistance genes in positive isolates of E. coli and K. pneumoniae was: tetA > tetB > tetC, qnrS > qnrB > qnrA, sulII > sulI > sulIII. The highest proportion of resistance genes was found in slurry (193 genes) followed by milk (71 genes). The overall pattern of resistant genes was tetA > sulII > qnrS. In conclusion, data from the present study suggested that commensal E. coli and Klebsiella may act as reservoirs of antimicrobial drug resistance genes which may be mobilised into human populations and untreated animal waste may be considered an important source of resistant bacteria leading to environmental pollution. | 2021 | 33544346 |
| 5276 | 15 | 0.9996 | Bacteriological quality, heavy metal and antibiotic resistance in Sapanca Lake, Turkey. Sapanca Lake is important as a source of drinking water. In this study, we aimed to detect the bacterial quality, the frequency of bacterial antibiotic and heavy metal resistance, and bioindicator bacteria in the water samples taken from Sapanca Lake in the period between 2008 and 2010. The resistance of bacterial isolates to certain antibiotics and heavy metal salts was investigated using disc diffusion and minimum inhibitory concentration techniques. Bacterial metabolic reactions were tested using the VITEK 2 Compact 30 micro identification system for identification of cultivable bacteria. Twenty-seven bacteria species belonging to three classes-Gammaproteobacteria, Bacilli, Flavobacteria-were recorded for the first time in Sapanca Lake. The highest indicator bacteria were recorded as 71 ± 3.1 × 10(4) CFU/100 ml in the summer season. The highest bacterial resistance was recorded as 90.47% against vancomycin in a total of 84 strains. Ampicillin (88.10%) and amoxicillin-clavulanate (64.29%) followed them. The resistance varied between 10.71 and 59.52% against cefuroxime, kanamycin, aztreonam, ceftazidime, cefotaxime, and oxacillin. The highest frequency against heavy metal salts was recorded as 74.19% against NiCl(2). The heavy metal resistance against Cu, Zn, Hg, and Cd detected as 52.38%, 46.42%, 33.33%, and 26.19%, respectively. The results showed that the occurrence of heavy metals and antibiotic sources in Sapanca Lake induced a tolerance in bacteria for the metal salts and antibiotic derivatives tested. The fluctuations in the indicator bacteria and the occurrence of pathogenic bacteria also showed the possibility that the coastal areas of Sapanca Lake had been exposed to contamination due to inadequate sewage treatment. | 2019 | 31243556 |
| 1360 | 16 | 0.9996 | First Report on a Randomized Investigation of Antimicrobial Resistance in Fecal Indicator Bacteria from Livestock, Poultry, and Humans in Tanzania. This study provides an estimate of antimicrobial resistance in intestinal indicator bacteria from humans (n = 97) and food animals (n = 388) in Tanzania. More than 70% of all fecal samples contained tetracycline (TE), sulfamethoxazole (STX), and ampicillin (AMP)-resistant coliforms, while cefotaxime (CTX)-resistant coliforms were observed in 40% of all samples. The average Log(10) colony forming units/g of CTX-resistant coliforms in samples from humans were 2.20. Of 390 Escherichia coli tested, 66.4% were resistant to TE, 54.9% to STX, 54.9% to streptomycin, and 36.4% to CTX. Isolates were commonly (65.1%) multiresistant. All CTX-resistant isolates contained bla(CTX-M) gene type. AMP- and vancomycin-resistant enterococci were rare, and the average concentrations in positive samples were low (log(10) 0.9 and 0.4, respectively). A low-to-moderate resistance (2.1-15%) was detected in 240 enterococci isolates to the drugs tested, except for rifampicin resistance (75.2% of isolates). The average number of sulII gene copies varied between Log(10) 5.37 and 5.68 with no significant difference between sample source, while cattle had significantly higher number of tetW genes than humans. These findings, based on randomly obtained samples, will be instrumental in designing antimicrobial resistance (AMR) intervention strategies for Tanzania. | 2018 | 28759321 |
| 5265 | 17 | 0.9996 | Prevalence of antibiotic-resistant fecal bacteria in a river impacted by both an antibiotic production plant and urban treated discharges. In this study, the abundance and spatial dynamics of antibiotic-resistant fecal bacteria (Escherichia coli, total coliforms and Enterococcus spp.) were determined in water and sediment samples from a river impacted by both antibiotic production plant (APP) and urban wastewater treatment plant (WWTP) discharges. Agar dilution and disk diffusion methods were also used for antimicrobial susceptibility testing. Two antimicrobial agents, cephalexin (25 μg/ml) and amoxicillin (50 μg/ml), were evaluated using the agar dilution method for E. coli, total coliforms (TC) and Enterococcus spp., whereas the degree of sensitivity or resistance of E. coli isolates to penicillin (10 U), ampicillin (10 μg), doxycycline (30 μg), tetracycline (30 μg), erythromycin (15 μg), azithromycin (15 μg) and streptomycin (10 μg) was performed using the disk diffusion method. Real-time PCR assays were used to determine the prevalence of three antibiotic-resistance genes (ARGs). The agar dilution method showed that most E. coli isolates and TC were resistant to amoxicillin, especially after receiving the APP discharges. Antibiotic resistances to amoxicillin and cephalexin were higher after the APP discharge point than after the WWTP effluent. The disk diffusion method revealed that 100% of bacterial isolates were resistant to penicillin and erythromycin. Multidrug-resistant bacteria were detected and showed a higher proportion at the WWTP discharge point than those in the APP. Highly multidrug-resistant bacteria (resistance to more than 4 antibiotics) were also detected, reaching mean values of 41.6% in water samples and 50.1% in sediments. The relative abundance of the blaTEM, blaCTX-M and blaSHV genes was higher in samples from the treatment plants than in those collected upstream from the discharges, especially for water samples collected at the APP discharge point. These results clearly demonstrate that both the APP and the WWTP contribute to the emergence and spread of antibiotic resistance in the environment. | 2014 | 24836130 |
| 5253 | 18 | 0.9996 | Effects of Cage Farming on Antimicrobial and Heavy Metal Resistance of Escherichia coli, Enterococcus faecium, and Lactococcus garvieae. OBJECTIVE: To characterize antibiotic resistance genes (ARGs) and heavy metal resistance genes (HMRGs) of Escherichia coli and Enterococcus faecium isolated from the sediment and Lactococcus garvieae isolated from fish. MATERIALS AND METHODS: The isolated bacteria were identified by sequencing 16S rRNA genes. After identification of the bacteria, tetracycline (tetA, tetB, tetD), erythromycin (ereA, ereB), sulfonamides (sulI, sulII), trimethoprim (dhfrA1), β-lactam (bla(TEM), bla(CTX), ampC), florfenicol (floR), and class 1 integron (Int1) resistance gene were then determined. The presence of HMRGs, including copper (copA), mercury (mer), cadmium, zinc, cobalt (czc), and nickel, cobalt cadmium (ncc), was also analyzed by PCR. All strains were checked for the presence of ARGs and/or HMRGs on the plasmid. RESULTS: The frequency of the β-lactam resistance gene was highest and ranged from 49.7% to 62.3%, followed by sulfonamides, tetracyclines, phenicols, and macrolide resistance genes. The cage culture fish farming practice showed significant effects on ARG frequency of bacteria isolated from the sediment, whereas it had no effect on the frequency of HMRGs. The most prevalent HMRG was determined as mercury-resistant mer gene in all bacteria. All four of the HMRGs were located on plasmids with frequency ranging from 1.20% to 32.53%. The presence of ARGs on plasmids ranged between 2.2% (Dhfr1) and 75% (AmpC, blactx, tetB), and plasmids did not contain tetD and ereB genes. CONCLUSION: The results of this study indicate that fish farming can significantly influence the antimicrobial resistance properties of bacteria isolated from sediment samples. | 2018 | 29733265 |
| 2968 | 19 | 0.9996 | The phenotypic and genotypic characteristics of antibiotic resistance in Escherichia coli populations isolated from farm animals with different exposure to antimicrobial agents. The aim of the study was to determine the influence of the presence or the absence of antibiotic input on the emergence and maintenance of resistance in commensal bacteria from food producing animals. The research material constituted E. coli isolates from two animal species: swine at different age from one conventional pig farm with antibiotic input in young pigs and from beef and dairy cattle originated from organic breeding farm. The sensitivity to 16 antimicrobial agents was tested, and the presence of 15 resistance genes was examined. In E. coli from swine, the most prevalent resistance was resistance to streptomycin (88.3%), co-trimoxazole (78.8%), tetracycline (57.3%) ampicillin (49.3%) and doxycycline (44.9%) with multiple resistance in the majority. The most commonly observed resistance genes were: bla(TEM) (45.2%), tetA (35.8%), aadA1 (35.0%), sul3 (29.5%), dfrA1 (20.4%). Differences in phenotypes and genotypes of E. coli between young swine undergoing prevention program and the older ones without the antibiotic pressure occurred. A disparate resistance was found in E. coli from cattle: cephalothin (36.9%), cefuroxime (18.9%), doxycycline (8.2%), nitrofurantoin (7.7%), and concerned mainly dairy cows. Among isolates from cattle, multidrug resistance was outnumbered by resistance to one or two antibiotics and the only found gene markers were: bla(SHV), (3.4%), tetA (1.29%), bla(TEM) (0.43%) and tetC (0.43%). The presented outcomes provide evidence that antimicrobial pressure contributes to resistance development, and enteric microflora constitutes an essential reservoir of resistance genes. | 2013 | 24053020 |