Characterization of Escherichia coli virulence genes, pathotypes and antibiotic resistance properties in diarrheic calves in Iran. - Related Documents




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122301.0000Characterization of Escherichia coli virulence genes, pathotypes and antibiotic resistance properties in diarrheic calves in Iran. BACKGROUND: Calf diarrhea is a major economic concern in bovine industry all around the world. This study was carried out in order to investigate distribution of virulence genes, pathotypes, serogroups and antibiotic resistance properties of Escherichia coli isolated from diarrheic calves. RESULTS: Totally, 76.45% of 824 diarrheic fecal samples collected from Isfahan, Chaharmahal, Fars and Khuzestan provinces, Iran were positive for E. coli and all of them were also positive for cnf2, hlyA, cdtIII, f17c, lt, st, stx1, eae, ehly, stx2 and cnf1 virulence genes. Chaharmahal had the highest prevalence of STEC (84.61%), while Isfahan had the lowest (71.95%). E. coli serogroups had the highest frequency in 1-7 days old calves and winter season. Distribution of ETEC, EHEC, AEEC and NTEC pathotypes among E. coli isolates were 28.41%, 5.07%, 29.52% and 3.49%, respectively. Statistical analyses were significant for presence of bacteria between various seasons and ages. All isolates had the high resistance to penicillin (100%), streptomycin (98.25%) and tetracycline (98.09%) antibiotics. The most commonly detected resistance genes were aadA1, sul1, aac[3]-IV, CITM, and dfrA1. The most prevalent serogroup among STEC was O26. CONCLUSIONS: Our findings should raise awareness about antibiotic resistance in diarrheic calves in Iran. Clinicians should exercise caution when prescribing antibiotics.201425052999
129610.9993Prevalence and antimicrobial resistance of Salmonellaisolates from goose farms in Northeast China. BACKGROUND: Salmonella is one of the most important enteric pathogenic bacteria that threatened poultry health. AIMS: This study aimed to investigate the prevalence and antimicrobial resistance of Salmonella isolates in goose farms. METHODS: A total of 244 cloacal swabs were collected from goose farms to detect Salmonella in Northeast China. Antimicrobial susceptibility, and resistance gene distribution of Salmonella isolates were investigated. RESULTS: Twenty-one Salmonella isolates were identified. Overall prevalence of Salmonella in the present study was 8.6%. Among the Salmonella isolates, the highest resistance frequencies belonged to amoxicillin (AMX) (85.7%), tetracycline (TET) and trimethoprim/sulfamethoxazole (SXT) (81%), followed by chloramphenicol (CHL) (76.2%), florfenicol (FLO) (71.4%), kanamycin (KAN) (47.6%), and gentamycin (GEN) (38.1%). Meanwhile, only 4.8% of the isolates were resistant to ciprofloxacin (CIP) and cefotaxime (CTX). None of the isolates was resistant to cefoperazone (CFP) and colistin B (CLB). Twenty isolates (95%) were simultaneously resistant to at least two antimicrobials. Ten resistance genes were detected among which the bla (TEM-1), cmlA, aac(6')-Ib-cr, sul1, sul2, sul3, and mcr-1.1 were the most prevalent, and presented in all 21 isolates followed by tetB (20/21), qnrB (19/21), and floR (15/21). CONCLUSION: Results indicated that Salmonella isolates from goose farms in Northeast China exhibited multi-drug resistance (MDR), harboring multiple antimicrobial resistance genes. Our results will be useful to design prevention and therapeutic strategies against Salmonella infection in goose farms.202033584841
136520.9993The frequency of tetracycline resistance genes in Escherichia coli strains isolated from healthy and diarrheic pet birds. BACKGROUND: Pet birds have close contact to human and resistant bacteria can transfer from birds to intestinal flora of human. AIMS: This study was carried out to determine the tetracycline resistance genes in Escherichia coli strains associated with enteric problem in pet birds. METHODS: Totally, 295 cloacal swabs were collected from 195 healthy and 100 diarrheic pet birds in Isfahan province, Iran. The presence of E. coli was identified by conventional bacteriological, biochemical, and molecular examinations. The presence of tetracycline resistance genes (tetA, tetB, tetC, tetD, tetE, tetG, tetK, tetL, tetM, tetO, and tetS genes) were examined using three multiplex PCR. RESULTS: The results showed that 18.9% and 43% of cloacal samples of healthy and diarrheic pet birds contained E. coli, respectively. The mean percentage of E. coli isolated from cloacal samples of diarrheic birds was significantly higher than the healthy birds (46.6 vs 23.1%). In healthy birds, out of 37 E. coli isolates, 10 isolates were resistant to tetracycline, harboring tetA and tetB genes (3 tetA vs 7 tetB), but in the diarrheic birds, of 26 resistance E. coli, 11, 12, and 3 strains contained tetA (42.3%), tetB (46.15), and tetA+tetB (11.53%) genes. The percentage of tet genes were significantly higher in diarrheic birds than healthy birds (58.9 vs 24.0%). CONCLUSION: Both resistant genes of tetA and tetB were detected in E. coli isolates that are related with efflux pump activity. These genes can be transferred between Gram-negative bacteria and they have the potential ability to be transferred to the environment and human flora.202135126542
129530.9993Phenotypic and genotypic characterisation of antimicrobial resistance in faecal bacteria from 30 Giant pandas. To study the prevalence of antimicrobial resistance in faecal bacteria from Giant pandas in China, 59 isolates were recovered from faecal pats of 30 Giant pandas. Antimicrobial susceptibility testing of the isolates was performed by the standardised disk diffusion method (Kirby-Bauer). Of the 59 study isolates, 32.20% were resistant to at least one antimicrobial and 16.95% showed multidrug-resistant phenotypes. Thirteen drug resistance genes [aph(3')-IIa, aac(6')-Ib, ant(3'')-Ia, aac(3)-IIa, sul1, sul2, sul3, tetA, tetC, tetM, cat1, floR and cmlA] were analysed using four primer sets by multiplex polymerase chain reaction (PCR). The detection frequency of the aph(3')-IIa gene was the highest (10.17%), followed by cmlA (8.47%). The genes aac(6')-Ib, sul2 and tetA were not detected. PCR products were confirmed by DNA sequence analysis. The results revealed that multidrug resistance was widely present in bacteria isolated from Giant pandas.200919168331
130740.9993Identification of shiga toxin and intimin coding genes in Escherichia coli isolates from pigeons (Columba livia) in relation to phylotypes and antibiotic resistance patterns. Shiga toxin-producing Escherichia coli (STEC) strains are responsible for outbreaks of human intestinal diseases worldwide. Pigeons are distributed in public areas and are potential reservoirs for pathogenic bacteria. One hundred fifty-four fresh fecal samples were obtained from trapped pigeons in southeast of Iran and were cultured for isolation of E. coli. The isolates were examined to determine the prevalence of stx1, stx2, and eae genes, antimicrobial resistance, and their phylotypes. The confirmed E. coli isolates (138) belong to four phylogenetic groups: A (54.34%), B1 (34.05%), B2 (3.62%), and D (7.79%). Thirteen (9.42%) isolates were positive for one of the examined genes. Eight isolates (5.79%) were positive for eae, four (2.89%) for stx2, and one isolate (1.44%) for stx1 gene. Phylotyping assays showed that eight eae-positive isolates fall into three phylogroups; A (three isolates), B1 (three isolates), and D (two isolates), whereas four stx2-positive isolates belonged to the A (three isolates) and D (one isolate) groups. The stx1-positive isolate belonged to phylogroup A. One hundred six isolates (76.81%) showed resistance to at least one of the selected antibacterial agents. The maximum resistance rate was against oxytetracycline (73.91%), and the minimum was against flumequine (2.17%). Twenty different patterns of drug resistance were observed. According to the results, pigeons could be considered as carriers of STEC strains. However, E. coli isolates of pigeon feces increase the potential of these birds to act as a reservoir of multiple antibiotic resistant bacteria.201222105907
218550.9992Isolation of multidrug-resistant Escherichia coli, Staphylococcus spp., and Streptococcus spp. from dogs in Chattogram Metropolitan Area, Bangladesh. OBJECTIVES: Antibacterial resistance is a great concern in human and food animal medicine, and it poses a significant concern in pet animals like dogs. This cross-sectional study was conducted to evaluate the antimicrobial resistance pattern of Escherichia coli, Staphylococcus spp., and Streptococcus spp. along with the carryover of some resistance genes in E. coli from dogs in the Chattogram metropolitan area, Bangladesh. MATERIALS AND METHODS: Rectal swab (n = 50), nasal swab (n = 50), and skin swab (n = 50) samples were collected from dogs having respiratory infections, skin infections, and/or enteritis, respectively. Three types of bacteria were identified and isolated by conventional bacteriological techniques and biochemical tests. Antimicrobial susceptibility testing was carried out against 12 antimicrobials by disk diffusion methods. Six resistance genes, namely bla (TEM), bla (CTX-M), tetA, tetB, Sul-I, and Sul-II, were screened for phenotypically resistant E. coli isolates by the polymerase chain reaction. RESULTS: A total of 39 (78%) E. coli, 25 (50%) Staphylococcus spp., and 24 (48%) Streptococcus spp. isolates were isolated from the rectal swab, nasal swab, and skin swab samples, respectively. In the cultural sensitivity test, the E. coli isolates showed resistance to ceftriaxone (79%) and sulfamethoxazole/trimethoprim (64%). Doxycycline (80%) demonstrated the highest resistance among Staphylococcus isolates, followed by sulfamethoxazole/trimethoprim (60%). Streptococcus isolates showed the highest resistance to penicillin (63%), followed by ceftriaxone (54%), while no isolate showed resistance to gentamycin. The prevalence of bla (TEM), bla (CTX-M), tetA, tetB, Sul-I, and Sul-II genes in phenotypically resistant E. coli isolates were 100%, 61.29%, 100%, 8.33%, 56%, and 72%, respectively. CONCLUSIONS: Spillover of such multidrug-resistant bacteria and resistance genes from pet dogs pose a serious public health risk.202033409311
130160.9992Phenotypic and Genotypic Assessment of Antibiotic Resistance of Staphylococcus aureus Bacteria Isolated from Retail Meat. BACKGROUND: Resistant Staphylococcus aureus (S. aureus) bacteria are determined to be one of the main causes of foodborne diseases. PURPOSE: This survey was done to assess the genotypic and phenotypic profiles of antibiotic resistance of S. aureus bacteria isolated from retail meat. METHODS: Four-hundred and eighty-five retail meat samples were collected and examined. S. aureus bacteria were identified using culture and biochemical tests. The phenotypic profile of antibiotic resistance was examined using the disk diffusion method. The genotypic pattern of antibiotic resistance was determined using the polymerase chain reaction. RESULTS: Forty-eight out of 485 (9.89%) raw retail meat samples were contaminated with S. aureus. Raw retail buffalo meat (16%) had the highest incidence of S. aureus, while raw camel meat (4%) had the lowest. S. aureus bacteria exhibited the uppermost incidence of resistance toward tetracycline (79.16%), penicillin (72.91%), gentamicin (60.41%), and doxycycline (41.666%). The incidence of resistance toward chloramphenicol (8.33%), levofloxacin (22.91%), rifampin (22.91%), and azithromycin (25%) was lower than other examined antibiotics. The most routinely detected antibiotic resistance genes were blaZ (58.33%), tetK (52.08%), aacA-D (33.33%), and ermA (27.08%). Cat1 (4.16%), rpoB (10.41%), msrA (12.50%), grlA (12.50%), linA (14.58%), and dfrA1 (16.66%) had the lower incidence rate. CONCLUSION: Raw meat of animals may be sources of resistant S. aureus which pose a hygienic threat about the consumption of raw meat. Nevertheless, further investigations are essential to understand supplementary epidemiological features of S. aureus in retail meat.202032440171
130970.9992Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli isolated from dairy cows with mastitis. Pulsed field gel electrophoresis (PFGE) patterns, susceptibility to 26 antimicrobial agents used in veterinary and human medicine, and prevalence of antimicrobial resistance genes of Escherichia coli isolated from cows with mastitis were evaluated. Among 135 E. coli isolates, PFGE analysis revealed 85 different genetic patterns. All E. coli were resistant to two or more antimicrobials in different combinations. Most E. coli were resistant to antimicrobials used in veterinary medicine including ampicillin (98.4%, >or=32 microg/ml) and many E. coli were resistant to streptomycin (40.3%, >or=64 microg/ml), sulfisoxazole (34.1%, >or=512 microg/ml), and tetracycline (24.8%, >or=16 microg/ml). Most E. coli were resistant to antimicrobials used in human medicine including aztreonam (97.7%, >or=32 microg/ml) and cefaclor (89.9%, >or=32 microg/ml). Some E. coli were resistant to nitrofurantoin (38%, >or=128 microg/ml), cefuroxime (22.5%, >or=32 microg/ml), fosfomycin (17.8%, >or=256 microg/ml). All E. coli were susceptible to ciprofloxacin and cinoxacin. Almost 97% (123 of 127) of ampicillin-resistant isolates carried ampC. Eleven of 52 (21.2%) streptomycin-resistant isolates carried strA, strB and aadA together and 29 streptomycin-resistant isolates (55.8%) carried aadA alone. Among 44 sulfisoxazole-resistant E. coli, 1 isolate (2.3%) carried both sulI and sulII, 12 (27.3%) carried sulI and 10 (22.7%) isolates carried sulII. Among 32 tetracycline-resistant isolates, 14 (43.8%) carried both tetA and tetC and 14 (43.8%) carried tetC. Results of this study demonstrated that E. coli from cows with mastitis were genotypically different, multidrug resistant and carried multiple resistance genes. These bacteria can be a reservoir for antimicrobial resistance genes and can play a role in the dissemination of antimicrobial resistance genes to other pathogenic and commensal bacteria in the dairy farm environment.200717544234
131080.9992Antimicrobial Resistance of Escherichia fergusonii Isolated from Broiler Chickens. The objective of this study was to investigate the antibiotic resistance of Escherichia fergusonii isolated from commercial broiler chicken farms. A total of 245 isolates from cloacal and cecal samples of 28- to 36-day-old chickens were collected from 32 farms. Isolates were identified using PCR, and their susceptibility to 16 antibiotics was determined by disk diffusion assay. All isolates were susceptible to meropenem, amikacin, and ciprofloxacin. The most common resistances were against ampicillin (75.1%), streptomycin (62.9%), and tetracycline (57.1%). Of the 184 ampicillin-resistant isolates, 127 were investigated using a DNA microarray carrying 75 probes for antibiotic resistance genetic determinants. Of these 127 isolates, the β-lactamase blaCMY2, blaTEM, blaACT, blaSHV, and blaCTX-M-15 genes were detected in 120 (94.5%), 31 (24.4%), 8 (6.3%), 6 (4.7%), and 4 (3.2%) isolates, respectively. Other detected genes included those conferring resistance to aminoglycosides (aadA1, strA, strB), trimethoprims (dfrV, dfrA1), tetracyclines (tetA, tetB, tetC, tetE), and sulfonamides (sul1, sul2). Class 1 integron was found in 35 (27.6%) of the ampicillin-resistant isolates. However, our data showed that the tested E. fergusonii did not carry any carbapenemase blaOXA genes. Pulsed-field gel electrophoresis revealed that the selected ampicillin-resistant E. fergusonii isolates were genetically diverse. The present study indicates that the monitoring of antimicrobial-resistant bacteria should include enteric bacteria such as E. fergusonii, which could be a reservoir of antibiotic resistance genes. The detection of isolates harboring extended-spectrum β-lactamase genes, particularly blaCTX-M-15, in this work suggests that further investigations on the occurrence of such genes in broilers are warranted.201627296596
133590.9992Prevalence of virulence factor, antibiotic resistance, and serotype genes of Pasteurella multocida strains isolated from pigs in Vietnam. AIM: The study was conducted to determine the prevalence and characterization of the Pasteurella multocida isolates from suspected pigs in Vietnam. MATERIALS AND METHODS: A total of 83 P. multocida strains were isolated from lung samples and nasal swabs collected from pigs associated with pneumonia, progressive atrophic rhinitis, or reproductive and respiratory symptoms. Isolates were subjected to multiplex polymerase chain reaction (PCR) for capsular typing, detection of virulence-associated genes and antibiotic resistance genes by PCR. The antimicrobial sensitivity profiles of the isolates were tested by disk diffusion method. RESULTS: All the isolates 83/83 (100%) were identified as P. multocida by PCR: serogroup A was obtained from 40/83 (48.19%), serogroup D was detected from 24/83 strains (28.91%), and serogroup B was found in 19/83 (22.35%) isolates. The presence of 14 virulence genes was reported including adhesins group (ptfA - 93.97%, pfhA - 93.97%, and fimA - 90.36%), iron acquisition (exbB - 100%, and exbD - 85.54%), hyaluronidase (pmHAS - 84.33%), and protectins (ompA - 56.62%, ompH 68.67%, and oma87 - 100%). The dermonecrotoxin toxA had low prevalence (19.28%). The antimicrobial susceptibility testing revealed that cephalexin, cefotaxime, ceftriaxone, ofloxacin, pefloxacin, ciprofloxacin, and enrofloxacin were the drugs most likely active against P. multocida while amoxicillin and tetracycline were inactive. The usage of PCR revealed that 63/83 isolates were carrying at least one of the drug resistance genes. CONCLUSION: Unlike other parts of the word, serotype B was prevalent among Vietnamese porcine P. multocida strains. The high antibiotic resistance detected among these isolates gives us an alert about the current state of imprudent antibiotic usage in controlling the pathogenic bacteria.202032636585
1311100.9992Prevalence and Molecular Characterization of Antimicrobial Resistance in Escherichia coli Isolated from Raw Milk and Raw Milk Cheese in Egypt. The goal of this study was to examine antimicrobial resistance and characterize the implicated genes in 222 isolates of Escherichia coli from 187 samples of raw milk and the two most popular cheeses in Egypt. E. coli isolates were tested for susceptibility to 12 antimicrobials by a disk diffusion method. Among the 222 E. coli isolates, 66 (29.7%) were resistant to one or more antimicrobials, and half of these resistant isolates showed a multidrug resistance phenotype (resistance to at least three different drug classes). The resistance traits were observed to tetracycline (27.5%), ampicillin (18.9%), streptomycin (18.5%), sulfamethoxazole-trimethoprim (11.3%), cefotaxime (4.5%), kanamycin (4.1%), ceftazidime (3.6%), chloramphenicol (2.3%), nalidixic acid (1.8%), and ciprofloxacin (1.4%). No resistance to fosfomycin and imipenem was observed. Tetracycline resistance genes tetA, tetB, and tetD were detected in 53 isolates, 9 isolates, and 1 isolate, respectively, but tetC was not detected. Aminoglycoside resistance genes strA, strB, aadA, and aphA1 were detected in 41, 41, 11, and 9 isolates, respectively. Sulfonamide resistance genes sul1, sul2, and sul3 were detected in 7, 25, and 3 isolates, respectively. Of 42 ampicillin-resistant isolates, bla(TEM), bla(CTX-M), and bla(SHV) were detected in 40, 9, and 3 isolates, respectively, and 10 (23.8%) ampicillin-resistant isolates were found to produce extended-spectrum β-lactamase. Each bla gene of extended-spectrum β-lactamase-producing E. coli was further subtyped to be bla(CTX-M-15), bla(CTX-M-104), bla(TEM-1), and bla(SHV-12). The class 1 integron was also detected in 28 resistant isolates, and three different patterns were obtained by PCR-restriction fragment length polymorphism. Sequencing analysis of the variable region revealed that four isolates had dfrA12/orfF/aadA2, two had aadA22, and one had dfrA1/aadA1. These data suggest that antimicrobial-resistant E. coli are widely distributed in the milk production and processing environment in Egypt and may play a role in dissemination of antimicrobial resistance to other pathogenic and commensal bacteria.201829323530
1334110.9992Intimin (eae) and virulence membrane protein pagC genes are associated with biofilm formation and multidrug resistance in Escherichia coli and Salmonella enterica isolates from calves with diarrhea. OBJECTIVES: This study aimed to evaluate the association of the intimin (eae) and pagC genes with biofilm formation and multidrug resistance (MDR) phenotype in Escherichia coli and Salmonella enterica collected from calves with diarrhea. RESULTS: Fecal samples (n: 150) were collected from calves with diarrhea. Of 150 fecal samples, 122 (81.3%) were culture positive and 115/122 (94.2%) were Gram-negative bacteria. Among them, E. coli (n = 64/115, 55.6%) was the most common isolate followed by S. enterica (n = 41/115, 35.6%). Also, 10 (8.6%) isolates were other Enterobacteriaceae bacteria including Klebsiella and Proteus species. Eighty-nine isolates (77.4%) from calf diarrhea, including 52 (81.3%) E. coli and 37 (90.2%) S. enterica were MDR. The eae and pagC genes were detected in 33 (51.5%) E. coli and 28 (68.3%) S. enterica isolates, respectively. There was a strong association between these genes and biofilm formation and MDR phenotype (P-value = 0.000). All E. coli isolates carrying the eae gene were biofilm producers and MDR. Also, all pagC-positive S. enterica isolates were MDR and 25 (89.3%) isolates of them produced biofilm.202236221149
1364120.9992Antimicrobial resistance patterns of Shiga toxin-producing Escherichia coli O157:H7 and O157:H7- from different origins. Shiga toxin-producing Escherichia coli (STEC) serotypes including O157:H7 (n = 129) from dairy cows, cull dairy cow feces, cider, salami, human feces, ground beef, bulk tank milk, bovine feces, and lettuce; and O157:H7- (n = 24) isolated from bovine dairy and bovine feedlot cows were evaluated for antimicrobial resistance against 26 antimicrobials and the presence of antimicrobial resistance genes (tetA, tetB, tetC, tetD, tetE, tetG, floR, cmlA, strA, strB, sulI, sulII, and ampC). All E. coli exhibited resistance to five or more antimicrobial agents, and the majority of isolates carried one or more target antimicrobial resistance gene(s) in different combinations. The majority of E. coli showed resistance to ampicillin, aztreonam, cefaclor, cephalothin, cinoxacin, and nalidixic acid, and all isolates were susceptible to chloramphenicol and florfenicol. Many STEC O157:H7 and O157:H7-isolates were susceptible to amikacin, carbenicillin, ceftriaxone, cefuroxime, ciprofloxacin, fosfomycin, moxalactam, norfloxacin, streptomycin, tobramycin, trimethoprim, and tetracycline. The majority of STEC O157:H7 (79.8%) and O157:H7- (91.7%) carried one or more antimicrobial resistance gene(s) regardless of whether phenotypically resistant or susceptible. Four tetracycline resistant STEC O157:H7 isolates carried both tetA and tetC. Other tetracycline resistance genes (tetB, tetD, tetE, and tetG) were not detected in any of the isolates. Among nine streptomycin resistant STEC O157:H7 isolates, eight carried strA-strB along with aadA, whereas the other isolate carried aadA alone. However, the majority of tetracycline and streptomycin susceptible STEC isolates also carried tetA and aadA genes, respectively. Most ampicillin resistant E. coli of both serotypes carried ampC genes. Among sulfonamide resistance genes, sulII was detected only in STEC O157:H7 (4 of 80 sulfonamide-resistant isolates) and sulI was detected in O157:H7- (1 of 16 sulfonamide resistant isolates). The emergence and dissemination of multidrug resistance in STEC can serve as a reservoir for different antimicrobial resistance genes. Dissemination of antimicrobial resistance genes to commensal and pathogenic bacteria could occur through any one of the horizontal gene transfer mechanisms adopted by the bacteria.200717536933
1281130.9991Antibiotic resistance in the pathogenic foodborne bacteria isolated from raw kebab and hamburger: phenotypic and genotypic study. BACKGROUND: In recent years, interest in the consumption of ready-to-eat (RTE) food products has been increased in many countries. However, RTE products particularly those prepared by meat may be potential vehicles of antibiotic-resistance foodborne pathogens. Considering kebab and hamburger are the most popular RTE meat products in Iran, this study aimed to investigate the prevalence and antimicrobial resistance of common foodborne pathogens (Escherichia coli, Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes) in raw kebab and hamburger samples collected from fast-food centers and restaurants. Therefore, total bacterial count (TBC), as well as the prevalence rates and antibiogram patterns of foodborne pathogens in the samples were investigated. Also, the presence of antibiotic-resistance genes (bla(SHV), bla(TEM,) bla(Z), and mecA) was studied in the isolates by PCR. RESULTS: The mean value of TBC in raw kebab and hamburger samples was 6.72 ± 0.68 log CFU/g and 6.64 ± 0.66 log CFU/g, respectively. E. coli had the highest prevalence rate among the investigated pathogenic bacteria in kebab (70%) and hamburger samples (48%). Salmonella spp., L. monocytogenes, and S. aureus were also recovered from 58, 50, and 36% of kebab samples, respectively. The contamination of hamburger samples was detected to S. aureus (22%), L. monocytogenes (22%), and Salmonella spp. (10%). In the antimicrobial susceptibility tests, all isolates exhibited high rates of antibiotic resistance, particularly against amoxicillin, penicillin, and cefalexin (79.66-100%). The bla(TEM) was the most common resistant gene in the isolates of E. coli (52.54%) and Salmonella spp. (44.11%). Fourteen isolates (23.72%) of E. coli and 10 isolates (29.41%) of Salmonella spp. were positive for bla(SHV). Also, 16 isolates (55.17%) of S. aureus and 10 isolates (27.27%) of L. monocytogenes were positive for mecA gene. CONCLUSIONS: The findings of this study showed that raw kebab and hamburger are potential carriers of antibiotic-resistance pathogenic bacteria, which can be a serious threat to public health.202134615465
1302140.9991A survey of prevalence and phenotypic and genotypic assessment of antibiotic resistance in Staphylococcus aureus bacteria isolated from ready-to-eat food samples collected from Tehran Province, Iran. BACKGROUND: Resistant Staphylococcus aureus (S. aureus) bacteria are considered among the major causes of foodborne diseases. This survey aims to assess genotypic and phenotypic profiles of antibiotic resistance in S. aureus bacteria isolated from ready-to-eat food samples. METHODS: According to the previously reported prevalence of S. aureus in ready-to-eat food samples, a total of 415 ready-to-eat food samples were collected from Tehran province, Iran. S. aureus bacteria were identified using culture and biochemical tests. Besides, the phenotypic antibiotic resistance profile was determined by disk diffusion. In addition, the genotypic pattern of antibiotic resistance was determined using the PCR. RESULTS: A total of 64 out of 415 (15.42%) ready-to-eat food samples were contaminated with S. aureus. Grilled mushrooms and salad olivieh harbored the highest contamination rate of (30%), while salami samples harbored the lowest contamination rate of 3.33%. In addition, S. aureus bacteria harbored the highest prevalence of resistance to penicillin (85.93%), tetracycline (85.93%), gentamicin (73.43%), erythromycin (53.12%), trimethoprim-sulfamethoxazole (51.56%), and ciprofloxacin (50%). However, all isolates were resistant to at least four antibiotic agents. Accordingly, the prevalence of tetK (70.31%), blaZ (64.06%), aacA-D (57.81%), gyrA (50%), and ermA (39.06%) was higher than that of other detected antibiotic resistance genes. Besides, AacA-D + blaZ (48.43%), tetK + blaZ (46.87%), aacA-D + tetK (39.06%), aacA-D + gyrA (20.31%), and ermA + blaZ (20.31%) were the most frequently identified combined genotypic patterns of antibiotic resistance. CONCLUSION: Ready-to-eat food samples may be sources of resistant S. aureus, which pose a hygienic threat in case of their consumption. However, further investigations are required to identify additional epidemiological features of S. aureus in ready-to-eat foods.202134635183
1288150.9991Assessment of virulence factors and antimicrobial resistance among the Pseudomonas aeruginosa strains isolated from animal meat and carcass samples. BACKGROUND: Pseudomonas aeruginosa bacteria are emerging causes of food spoilage and foodborne diseases. Raw meat of animal species may consider a reservoir of P. aeruginosa strains. OBJECTIVES: The present survey was done to assess the prevalence, antibiotic resistance properties and distribution of virulence factors among the P. aeruginosa strains isolated from raw meat and carcass surface swab samples of animal species. METHODS: Five hundred and fifty raw meat and carcass surface swab samples were collected from cattle and sheep species referred to as slaughterhouses. P. aeruginosa bacteria were identified using culture and biochemical tests. The pattern of antibiotic resistance was determined by disk diffusion. The distribution of virulence and antibiotic resistance genes was determined using polymerase chain reaction. RESULTS: Forty-seven of 550 (8.54%) examined samples were contaminated with P. aeruginosa. The prevalence of P. aeruginosa in raw meat and carcass surface swab samples were 6.57 and 12%, respectively. P. aeruginosa isolates showed the maximum resistance rate toward penicillin (87.23%), ampicillin (85.10%), tetracycline (85.10%), gentamicin (65.95%) and trimethoprim (57.44%). The most commonly detected antibiotic resistance genes were BlaCTX-M (53.19%), blaDHA (42.55%) and blaTEM (27.65%). The most commonly detected virulence factors was ExoS (42.55%), algD (31.91%), lasA (31.91%), plcH (31.91%) and exoU (25.53%). CONCLUSIONS: Meat and carcass surface swab samples may be sources of resistant and virulent P. aeruginosa, which pose a hygienic threat in their consumption. However, further investigations are required to identify additional epidemiological features of P. aeruginosa in meat and carcass surface samples.202336418165
1313160.9991Molecular epidemiology of ceftiofur-resistant Escherichia coli isolates from dairy calves. Healthy calves (n = 96, 1 to 9 weeks old) from a dairy herd in central Pennsylvania were examined each month over a five-month period for fecal shedding of ceftiofur-resistant gram-negative bacteria. Ceftiofur-resistant Escherichia coli isolates (n = 122) were characterized by antimicrobial resistance (disk diffusion and MIC), serotype, pulsed-field gel electrophoresis subtypes, beta-lactamase genes, and virulence genes. Antibiotic disk diffusion assays showed that the isolates were resistant to ampicillin (100%), ceftiofur (100%), chloramphenicol (94%), florfenicol (93%), gentamicin (89%), spectinomycin (72%), tetracycline (98%), ticarcillin (99%), and ticarcillin-clavulanic acid (99%). All isolates were multidrug resistant and displayed elevated MICs. The E. coli isolates belonged to 42 serotypes, of which O8:H25 was the predominant serotype (49.2%). Pulsed-field gel electrophoresis classified the E. coli isolates into 27 profiles. Cluster analysis showed that 77 isolates (63.1%) belonged to one unique group. The prevalence of pathogenic E. coli was low (8%). A total of 117 ceftiofur-resistant E. coli isolates (96%) possessed the bla(CMY2) gene. Based on phenotypic and genotypic characterization, the ceftiofur-resistant E. coli isolates belonged to 59 clonal types. There was no significant relationship between calf age and clonal type. The findings of this study revealed that healthy dairy calves were rapidly colonized by antibiotic-resistant strains of E. coli shortly after birth. The high prevalence of multidrug-resistant nonpathogenic E. coli in calves could be a significant source of resistance genes to other bacteria that share the same environment.200616751500
1225170.9991Escherichia coli serogroups in slaughterhouses: Antibiotic susceptibility and molecular typing of isolates. This study aimed to investigate the contamination of carcasses and slaughterhouse environment with Escherichia coli O157:H7 and non-O157 serogroups (O45:H2, O103:H2, O121:H19, O145:H28, O26:H11, O111:H8). For this purpose, a total of 150 samples (30 carcasses, 30 shredding units, 30 knives, 30 slaughterhouse waste water and 30 wall surfaces) were collected from 5 different slaughterhouses in Kayseri, Turkey. The conventional and molecular methods were performed in order to detect Escherichia coli and its serogroups. Of the 150 samples, 55 (36%) were found to be contaminated with E. coli. Among isolates, E. coli serogroup (O157:H7) were detected in 2 (11%) carcass and 2 (11%) wastewater samples. None of the E. coli isolates harbored tested genes (stx1, stx2, eaeA, and hylA). Effective infection control measures and antibiotic stewardship programs should be adopted to limit the spread of multidrug-resistant bacteria. It was also deduced that these isolates resistance to different antibiotics could be hazardous for public health.202235427957
1299180.9991Prevalence, Drug Resistance, and Virulence Genes of Potential Pathogenic Bacteria in Pasteurized Milk of Chinese Fresh Milk Bar. Fresh Milk Bar (FMB), an emerging dairy retail franchise, is used to instantly produce and sell pasteurized milk and other dairy products in China. However, the quality and safety of pasteurized milk in FMB have received little attention. The objective of this study was to investigate the prevalence, antimicrobial resistance, and virulence genes of Escherichia coli, Staphylococcus aureus, and Streptococcus in 205 pasteurized milk samples collected from FMBs in China. Four (2.0%) isolates of E. coli, seven (3.4%) isolates of S. aureus, and three (1.5%) isolates of Streptococcus agalactiae were isolated and identified. The E. coli isolates were resistant to amikacin (100%), streptomycin (50%), and tetracycline (50%). Their detected resistance genes include aac(3)-III (75%), blaTEM (25%), aadA (25%), aac(3)-II (25%), catI (25%), and qnrB (25%). The S. aureus isolates were mainly resistant to penicillin G (71.4%), trimethoprim-sulfamethoxazole (71.4%), kanamycin (57.1%), gentamicin (57.1%), amikacin (57.1%), and clindamycin (57.1%). blaZ (42.9%), mecA (28.6%), ermB (14.3%), and ermC (14.3%) were detected as their resistance genes. The Streptococcus strains were mainly resistant to tetracycline (66.7%) and contained the resistance genes pbp2b (33.3%) and tetM (33.3%). The virulence genes eae and stx2 were only found in one E. coli strain (25%), sec was detected in two S. aureus strains (28.6%), and bca was detected in one S. agalactiae strain (33.3%). The results of this study indicate that bacteria with drug resistance and virulence genes isolated from the pasteurized milk of FMB are a potential risk to consumers' health.202134129676
2410190.9991Phenotypic and molecular characterization of antimicrobial resistance in Trueperella pyogenes strains isolated from bovine mastitis and metritis. BACKGROUND: Trueperella pyogenes is one of the most clinically imperative bacteria responsible for severe cases of mastitis and metritis, particularly in postpartum dairy cows. The bacterium has emergence of antibiotic resistance and virulence characters. The existing research was done to apprise the phenotypic and genotypic evaluation of antibiotic resistance and characterization of virulence factors in the T. pyogenes bacteria of bovine mastitis and metritis in postpartum cows. METHODS: Two-hundred and twenty-six bovine mastitic milk and 172 uterine swabs were collected and transferred to laboratory. Samples were cultured and T. pyogenes isolates were subjected to disk diffusion and DNA extraction. Distribution of virulence and antibiotic resistance genes was studied by PCR. RESULTS: Thirty-two out of 226 (14.15%) mastitic milk and forty-one out of 172 (23.83%) uterine swab samples were positive for T. pyogenes. Isolates of mastitic milk harbored the highest prevalence of resistance toward gentamicin (100%), penicillin (100%), ampicillin (90.62%), amoxicillin (87.50%) and trimethoprim-sulfamethoxazole (87.50%), while those of metritis harbored the highest prevalence of resistance toward ampicillin (100%), amoxicillin (100%), gentamicin (97.56%), penicillin (97.56%) and cefalexin (97.56%). AacC, aadA1, aadA2 and tetW were the most generally perceived antibiotic resistance genes. All bacteria harbored plo (100%) and fimA (100%) virulence factors. NanP, nanH, fimC and fimE were also the most generally perceived virulence factors. CONCLUSIONS: All bacteria harbored plo and fimA virulence factors which showed that they can use as specific genetic markers with their important roles in pathogenicity of T. pyogenes bacteria. Phenotypic pattern of antibiotic resistance was confirmed by genotypic characterization of antibiotic resistance genes.201931881834