Molecular and Conventional Analysis of Acute Diarrheal Isolates Identifies Epidemiological Trends, Antibiotic Resistance and Virulence Profiles of Common Enteropathogens in Shanghai. - Related Documents




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266501.0000Molecular and Conventional Analysis of Acute Diarrheal Isolates Identifies Epidemiological Trends, Antibiotic Resistance and Virulence Profiles of Common Enteropathogens in Shanghai. Objective: To investigate prevalence of acute diarrhea in Shanghai and analyze virulence associated-genes and antibiotic resistance of major enteropathogens using combination of conventional and molecular epidemiology methods. Method: The 412 stool specimens were obtained by systematic sampling from diarrhea patients throughout entire year 2016. Bacterial and viral pathogens were identified and bacterial isolates were cultured and screened for antibiotic resistance profiles. Two most prevalent bacteria, Vibrio parahaemolyticus and Salmonella were further typed by multi-locus sequence typing (MLST) and analyzed for presence of virulence-associated genes. The association between virulence genes, resistance phenotypes and genetic diversities was analyzed. Results: Among stool specimens testing positive for pathogens (23.1%), 59 bacterial and 36 viral pathogens were identified. V. parahaemolyticus (27/412, 6.6%), Salmonella (23/412, 5.6%) and norovirus GII (21/412, 5.1%) were three most-commonly found. Most bacterial isolates exhibited high levels of antibiotic resistance with high percentage of MDR. The drug resistance rates of V. parahaemolyticus and Salmonella isolates to cephalosporins were high, such as 100.0 and 34.8% to CFX, 55.6 and 43.4% to CTX, 92.6 and 95.7% to CXM, respectively. The most common resistance combination of V. parahaemolyticus and Salmonella was cephalosporins and quinolone. The dominant sequence types (STs) of V. parahaemolyticus and Salmonella were ST3 (70.4%) and ST11 (43.5%), respectively. The detection rates of virulence genes in V. parahaemolyticus were tlh (100%) and tdh (92.6%), without trh and ureR. Most of the Salmonella isolates were positive for the Salmonella pathogenicity islands (SPIs) genes (87-100%), and some for Salmonella plasmid virulence (SPV) genes (34.8% for spvA and spvB, 43.5% for spvC). In addition, just like the drug resistance, virulence genes exhibited wide-spread distribution among the different STs albeit with some detectable frequency linkage among Salmonella STs. Conclusion: Bacterial infections are still the major cause of severe diarrheas in Shanghai. The most common bacteria V. parahaemolyticus and Salmonella show molecular characteristics consistent with preselection of highly virulent types with exceedingly high level of antibiotic resistance.201829556217
297410.9998Diversity of Virulence Genes in Multidrug Resistant Escherichia coli from a Hospital in Western China. BACKGROUND: Escherichia coli strains are the most commonly isolated bacteria in hospitals. The normally harmless commensal E. coli can become a highly adapted pathogen, capable of causing various diseases both in healthy and immunocompromised individuals, by acquiring a combination of mobile genetic elements. Our aim was to characterize E. coli strains from a hospital in western China to determine their virulence and antimicrobial resistance potential. METHODS: A total of 97 E. coli clinical isolates were collected from the First Affiliated Hospital of Chengdu Medical College from 2015 to 2016. Microbiological methods, PCR, and antimicrobial susceptibility tests were used in this study. RESULTS: The frequency of occurrence of the virulence genes fimC, irp2, fimH, fyuA, lpfA, hlyA, sat, and cnf1 in the E. coli isolates was 93.81, 92.78, 91.75, 84.54, 41.24, 32.99, 28.86, and 7.22%, respectively. Ninety-five (97.9%) isolates carried two or more different virulence genes. Of these, 44 (45.4%) isolates simultaneously harbored five virulence genes, 24 (24.7%) isolates harbored four virulence genes, and 17 (17.5%) isolates harbored six virulence genes. In addition, all E. coli isolates were multidrug resistant and had a high degree of antimicrobial resistance. CONCLUSION: These results indicate a high frequency of occurrence and heterogeneity of virulence gene profiles among clinical multidrug resistant E. coli isolates. Therefore, appropriate surveillance and control measures are essential to prevent the further spread of these isolates in hospitals.201931824179
266820.9998Genotyping and distribution of putative virulence factors and antibiotic resistance genes of Acinetobacter baumannii strains isolated from raw meat. BACKGROUND: Acinetobacter baumannii strains with multiple antimicrobial resistance are primarily known as opportunistic nosocomial bacteria but they may also be regarded as emerging bacterial contaminants of food samples of animal origin. Here we aimed to study the molecular characteristics of the A. baumanni strains isolated from raw meat samples. METHODS: A total of 22 A. baumanni strains were isolated from 126 animal meat samples and were genotyped by ERIC-PCR method and by PCR detection of their virulence and antimicrobial resistance determinants. A. baumannii strains with 80% and more similarities were considered as one cluster. RESULTS: Sixteen different genetic clusters were found amongst the 22 A. baumanni strains. Of the 22 strains, 12 (54.54%) had similar genetic cluster. A. baumannii strains exhibited the highest percentage of resistance against tetracycline (90.90%), trimethoprim (59.09%), cotrimoxazole (54.54%) and gentamicin (50.00%). TetA (81.81%), tetB (72.72%), dfrA1 (63.63%), aac(3)-IV (63.63%), sul1 (63.63%) and aadA1 (45.45%) were the most commonly detected antibiotic resistance genes. FimH (81.81%), afa/draBC (63.63%), csgA (63.63%), cnf1 (59.09%), cnf2 (54.54%) and iutA (50.00%) were the most commonly detected virulence factors. A. baumannii strains isolated from the chicken meat samples had the highest similarities in the genetic cluster. CONCLUSIONS: A. baumannii strains with similar genetic cluster (ERIC-Type) had the same prevalence of antibiotic resistance, antibiotic resistance genes and virulence factors. Genetic cluster of the A. baumannii strains is the main factor affected the similarities in the genotypic and phenotypic properties of the A. baumannii strains.201830323923
297330.9998An evaluation of multidrug-resistant Escherichia coli isolates in urinary tract infections from Aguascalientes, Mexico: cross-sectional study. BACKGROUND: Uropathogenic Escherichia coli (UPEC) are one of the main bacteria causing urinary tract infections (UTIs). The rates of UPEC with high resistance towards antibiotics and multidrug-resistant bacteria have increased dramatically in recent years and could difficult the treatment. METHODS: The aim of the study was to determine multidrug-resistant bacteria, antibiotic resistance profile, virulence traits, and genetic background of 110 E. coli isolated from community (79 isolates) and hospital-acquired (31 isolates) urinary tract infections. The plasmid-mediated quinolone resistance genes presence was also investigated. A subset of 18 isolates with a quinolone-resistance phenotype was examined for common virulence genes encoded in diarrheagenic and extra-intestinal pathogenic E. coli by a specific E. coli microarray. RESULTS: Female children were the group most affected by UTIs, which were mainly community-acquired. Resistance to trimethoprim-sulfamethoxazole, ampicillin, and ampicillin-sulbactam was most prevalent. A frequent occurrence of resistance toward ciprofloxacin (47.3%), levofloxacin (43.6%) and cephalosporins (27.6%) was observed. In addition, 63% of the strains were multidrug-resistant (MDR). Almost all the fluoroquinolone (FQ)-resistant strains showed MDR-phenotype. Isolates from male patients were associated to FQ-resistant and MDR-phenotype. Moreover, hospital-acquired infections were correlated to third generation cephalosporin and nitrofurantoin resistance and the presence of kpsMTII gene. Overall, fimH (71.8%) and fyuA (68.2%), had the highest prevalence as virulence genes among isolates. However, the profile of virulence genes displayed a great diversity, which included the presence of genes related to diarrheagenic E. coli. Out of 110 isolates, 25 isolates (22.7%) were positive to qnrA, 23 (20.9%) to qnrB, 7 (6.4%) to qnrS1, 7 (6.4%) to aac(6')lb-cr, 5 (4.5%) to qnrD, and 1 (0.9%) to qnrC genes. A total of 12.7% of the isolates harbored bla(CTX-M) genes, with bla(CTX-M-15) being the most prevalent. CONCLUSIONS: Urinary tract infection due to E. coli may be difficult to treat empirically due to high resistance to commonly used antibiotics. Continuous surveillance of multidrug resistant organisms and patterns of drug resistance are needed in order to prevent treatment failure and reduce selective pressure. These findings may help choosing more suitable treatments of UTI patients in this region of Mexico.201830041652
297740.9998Molecular Detection of Antibiotic Resistance Genes in Shiga Toxin-Producing E. coli Isolated from Different Sources. Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen associated with human gastroenteritis outbreaks. Extensive use of antibiotics in agriculture selects resistant bacteria that may enter the food chain and potentially causes foodborne illnesses in humans that are less likely to respond to treatment with conventional antibiotics. Due to the importance of antibiotic resistance, this study aimed to investigate the combination of phenotypic and genotypic antibiotic resistance in STEC isolates belonging to serogroups O26, O45, O103, O104, O111, O121, O145, and O157 using disc diffusion and polymerase chain reaction (PCR), respectively. All strains were phenotypically resistant to at least one antibiotic, with 100% resistance to erythromycin, followed by gentamicin (98%), streptomycin (82%), kanamycin (76%), and ampicillin (72%). The distribution of antibiotic resistance genes (ARGs) in the STEC strains was ampC (47%), aadA1 (70%), ere(A) (88%), bla(SHV) (19%), bla(CMY) (27%), aac(3)-I (90%), and tet(A) (35%), respectively. The results suggest that most of the strains were multidrug-resistant (MDR) and the most often observed resistant pattern was of aadA1, ere(A), and aac(3)-I genes. These findings indicate the significance of monitoring the prevalence of MDR in both animals and humans around the globe. Hence, with a better understanding of antibiotic genotypes and phenotypes among the diverse STEC strains obtained, this study could guide the administration of antimicrobial drugs in STEC infections when necessary.202133804818
267650.9998Characterization of commensal Escherichia coli isolates from slaughtered sheep in Mexico. INTRODUCTION: Commensal Escherichia coli is defined as bacteria without known virulence factors that could be playing a specific role in some diseases; however, they could be responsible to disseminate antimicrobial resistance genes to other microorganisms. This study aimed to characterize the commensal E. coli isolates obtained from slaughtered sheep in the central region of Mexico. METHODOLOGY: Isolates were classified as commensal E. coli when distinctive genes related to diarrheagenic pathotypes (stx1, stx2, eae, bfp, LT, stp, ipaH, and aggR) were discarded by PCR. Identification of serotype, phylogenetic group, and antimicrobial resistance was also performed. RESULTS: A total of 41 isolates were characterized. The phylogenetic groups found were B1 in 37 isolates (90.2%), A in 2 (4.8%), and 1 isolate (2.4%) for C and D groups. Serotypes associated with diarrhea in humans (O104:H2 and O154:NM) and hemolytic uremic syndrome (O8:NM) were detected. Thirty-three isolates (80%) were resistant to ceftazidime, 23 (56%), to tetracycline 8 (19.5%) to ampicillin, and 1 to amikacin. Six isolates (14.6%) were multidrug-resistant. CONCLUSIONS: This study provides new information about commensal E. coli in slaughtered sheep, high percentages of resistance to antibiotics, and different profiles of antimicrobial resistance were found, their dissemination constitute a risk factor towards the consuming population.202134898507
267360.9998Geographical and ecological analysis of resistance, coresistance, and coupled resistance to antimicrobials in respiratory pathogenic bacteria in Spain. A multicenter susceptibility surveillance (the S.A.U.C.E. project) including 2,721 Streptococcus pneumoniae, 3,174 Streptococcus pyogenes, and 2,645 Haemophilus influenzae consecutive isolates was carried out in 25 hospitals all over Spain from November 2001 to October 2002 to evaluate the current epidemiology of resistance of the main bacteria involved in community-acquired respiratory tract infections. Susceptibility testing was performed in a single centralized laboratory by a broth microdilution method. The prevalence of resistant S. pneumoniae strains was 0.4% for cefotaxime, 4.4% for amoxicillin and amoxicillin-clavulanic acid, 25.6% for cefuroxime-axetil, 34.5% for erythromycin, clarithromycin, and azithromycin, and 36.0% for cefaclor. Phenotypes of resistance to erythromycin were MLS(B) (macrolide-lincosamide-streptogramin B) in 89.9% (gene ermB) and M (macrolide) in 9.7% of cases (gene mefA). No strain harbored both genes simultaneously. Serotypes 19, 6, 23, 14, and 3 were the most prevalent, accounting for 54.6% of the total isolates. Resistance to macrolides seems to be the most alarming point, since among penicillin-susceptible isolates it reached 15.1% compared to 55.8% among penicillin-resistant strains. Geographically, a number of regions had rates of erythromycin resistance above 40% (even higher in children). Resistance to erythromycin was also high in S. pyogenes isolates: mean regional 33.2%, beta-lactamase-producing H. influenzae were 20%, whereas 4.4% had a beta-lactamase-negative, ampicillin-resistant phenotype. We highlight the importance of different geographical frequencies of coresistance (associations of resistance to different drugs within the same species) and coupled resistance (association of resistance between different species) probably resulting from different local coselective events.200515855520
116370.9997A Three-Year Look at the Phylogenetic Profile, Antimicrobial Resistance, and Associated Virulence Genes of Uropathogenic Escherichia coli. Uropathogenic Escherichia coli is the most common cause of urinary tract infections, resulting in about 150 million reported annual cases. With multidrug resistance on the rise and the need for global and region surveillance, this investigation looks at the UPEC isolates collected for a 3-year period, with a view of ascertaining their antimicrobial susceptibility patterns and associated virulence determinants. The identification of bacteria isolates, antimicrobial susceptibility, and extended-spectrum beta-lactamases (ESBLs) production was determined with a Vitek 2 Compact Automated System (BioMerieux, Marcy L'Etoile, France). ESBLs were confirmed by the combined disc test (CDT) and basic biochemical test. The isolates were distributed into A (11%), B1 (6%), B2 (62.4%), and D (20.6%). Resistance to the penicillin group was high, between 88% and 100%. Additionally, resistance was high to cephalosporins (100%) in 2017 and 2018. The isolates were all sensitive to tigecycline, while resistance against imipenem and meropenem was low, at 4-12% in 2017 and 2018 and 0% in 2019. The results also showed that ESBL isolates were seen in 2017 and 2018. They were confirmed positive to CTX/CLA (88.5%) and CAZ/CLA (85%). By 2019, the number of resistant isolates reduced, showing only 4% ESBL isolates. Two virulence genes, fimH (46%) and papE/F (15%), were detected among the isolates by PCR. In conclusion, this study found that phylogroups B2 and D carried the most virulence genes as well as MDR and ESBL characteristics, suggesting the UPEC strains to be extraintestinal pathogens responsible for UTIs.202235745485
266780.9997Prevalence, virulence and antimicrobial resistance patterns of Aeromonas spp. isolated from children with diarrhea. BACKGROUND: Aeromonas spp. cause various intestinal and extraintestinal diseases. These bacteria are usually isolated from fecal samples, especially in children under five years old. The aim of this study was to assess the prevalence of Aeromonas spp. and their antimicrobial resistance profile in children with diarrhea referred to the Children Medical Center in Tehran, between 2013 and 2014. METHODS: A total number of 391 stool samples were collected from children with ages between 1 day and 14 years old, with diarrhea (acute or chronic), referred to the Children Hospital, Tehran, Iran, between 2013 and 2014. Samples were enriched in alkaline peptone water broth for 24 hours at 37 °C and then cultured. Suspicious colonies were analyzed through biochemical tests. Furthermore, antimicrobial susceptibility tests were carried out for the isolates. Isolates were further studied for act, ast, alt, aerA and hlyA virulence genes using polymerase chain reaction. RESULTS: In total, 12 isolates (3.1%) were identified as Aeromonas spp.; all were confirmed using the API-20E test. Of these isolates, five A. caviae (42%), four A. veronii (33%) and three A. hydrophila (25%) were identified in cases with gastroenteritis. Second to ampicillin (which was included in the growth medium used), the highest rate of antimicrobial resistance was seen against nalidixic acid and trimethoprim-sulfamethoxazole (5 isolates each, 41.6%) and the lowest rate of antimicrobial resistance was seen against gentamicin, amikacin and cefepime (none of the isolates). Results included 76.4% act, 64.7% ast, 71.5% alt, 83.3% aerA and 11.7% hlyA genes. CONCLUSION: Aeromonas spp. are important due to their role in diarrhea in children; therefore, isolation and identification of these fecal pathogens should seriously be considered in medical laboratories. Since virulence genes play a significant role in gastroenteritis symptoms caused by these bacteria, Aeromonas species that include virulence genes are potentially suspected to cause severe infections. Moreover, bacterial antimicrobial resistance is increasing, especially against trimethoprim-sulfamethoxazole and nalidixic acid.201627622161
233390.9997Prevalence of USP and hlyA Genes and Association with Drug Resistance in Uropathogenic Escherichia coli Isolated from Patients in a Tertiary Hospital from Southeast China. E. coli was cultured from the urine of patients from the tertiary hospital located in Southeast China from 2017 to 2019. The species were identified, drug sensitivity test was performed, and the presence of the virulence genes USP and hlyA was determined. A total of 483 strains of E. coli were isolated, including 132 from patients with urinary tract infection (UTI). The resistance to ciprofloxacin was more common in non-UTI patients, while resistance to gentamycin was significantly higher in the UTI group. In the UTI group, the proportions of isolated bacteria with the virulence USP (40.15%) and hlyA (8.33%) genes were significantly higher than in the non-UTI group (19.60 and 2.56%, respectively). The rate of resistance of E. coli toward levofloxacin in the USP(+) group was significantly (p<0.05) higher than in the USP- group. Thus, we revealed the differences in the rate of drug resistance and prevalence of USP and hlyA between the UTI and non-UTI groups. Furthermore, the presence of the USP gene was found to be associated with greater resistance to levofloxacin.202236437317
2972100.9997Genetic characterisation of class 1 integrons among multidrug-resistant Salmonella serotypes in broiler chicken farms. OBJECTIVES: Antimicrobial resistance in Salmonella serotypes has been reported. Integrons play an important role in the dissemination of antimicrobial resistance genes in bacteria. Scarce literature is available on the identification of integrons in Salmonella isolated from broiler chickens. In this study, antimicrobial susceptibility testing and characterisation of class 1 integrons among multidrug-resistant (MDR) Salmonella enterica serotypes in broiler chicken farms in Egypt were performed. METHODS: Antimicrobial susceptibility was determined by the disk diffusion method. PCR was performed to detect antimicrobial resistance genes and class 1 integrons in the tested Salmonella serotypes. Gene sequencing of the variable region of a class 1 integron was performed. RESULTS: Salmonella spp. were detected in 26 (13.5%) of 192 broiler samples, with Salmonella Enteritidis being the most frequently detected serotype, followed by Salmonella Kentucky and Salmonella Typhimurium and other serotypes. A very high resistance rate was observed to trimethoprim/sulfamethoxazole (100%), whilst a low resistance rate was observed to cefuroxime (57.7%). MDR S. enterica isolates displayed resistance to ciprofloxacin and azithromycin. Class 1 integrons were detected in 20 (76.9%) of the 26 Salmonella isolates. A high prevalence of class 1 integrons, as the first recorded percentage in the literature, associated with MDR Salmonella isolates was observed. CONCLUSIONS: Antimicrobial resistance rates in Salmonella serotypes from broiler chicken farms were alarming, especially for ciprofloxacin and azithromycin. Thus, another therapeutic strategy other than antimicrobials is recommended to prevent outbreaks of MDR Salmonella.201829684574
2666110.9997The Characteristics of Multilocus Sequence Typing, Virulence Genes and Drug Resistance of Klebsiella pneumoniae Isolated from Cattle in Northern Jiangsu, China. Klebsiella pneumoniae (K. pneumoniae) induced bovine mastitis has been becoming one of the dominantly pathogenic bacteria in cases of bovine mastitis, and is threatening public health through dairy products. In order to explore the characteristics of multilocus sequence typing (MLST), virulence gene carrying, and the relationship between virulence genes and the antibiotic resistance of Klebsiella pneumoniae from dairy cattle in northern Jiangsu, 208 dairy milk samples were collected from four dairy farms in northern Jiangsu. A total of 68 isolates were obtained through bacterial isolation, purification, and 16S rDNA identification. Eleven virulence genes were detected by specific PCR. The susceptibility of the isolates to antimicrobials was analyzed using the Kirby-Bauer method. The Pearson correlation coefficient was used to analyze the correlation between the presence of virulence genes and the phenotype of drug resistance. ST 2661 was the most prevalent type of K. pneumoniae (13/68, 19.1%) among the 23 ST types identified from the 68 isolates. The virulence gene allS was not detected, but the positive detection rates of the virulence genes fimH, ureA, uge and wabG were 100.0%. Notably, the detection rates of genes rmpA and wcaG, related to the capsular polysaccharide, were 4.4% and 11.8%, respectively, which were lower than those of genes related to siderophores (kfuBC, ybtA and iucB at 50.0%, 23.5%, and 52.9%, respectively). The K. pneumoniae isolates were sensitive to ciprofloxacin, nitrofurantoin, and meropenem. However, the resistance rate to penicillin was the highest (58/68, 85.3%), along with resistance to amoxicillin (16/68, 23.5%). The results revealed the distribution of 23 ST types of K. pneumoniae from the milk from bovine-mastitis-infected dairy cows in northern Jiangsu, and the expression or absence of the virulence gene kfuBC was related to the sensitivity to antibiotics. The current study provides important information relating to the distribution and characteristics of K. pneumoniae isolated from dairy cows with clinical bovine mastitis, and is indicative of strategies for improving the treatment of K. pneumoniae-induced bovine mastitis.202236230368
2151120.9997Study of the Genomic Characterization of Antibiotic-Resistant Escherichia Coli Isolated From Iraqi Patients with Urinary Tract Infections. Urinary tract infection is one of the last diseases prevalent in humans, with various causative agents affecting 250 million people annually, This study analyzed UTIs in Iraqi patients caused by Escherichia coli. ESBL enzymes contribute to antibiotic resistance. The research aimed to analyze ESBL gene frequency, resistance patterns, and genetic diversity of E. coli strains; Between Dec 2020 and May 2021, 200 urine samples were collected, cultured on blood agar, EMB, and MacConkey's plates, samples incubated at 37 °C for 24 h. Positive samples (> 100 cfu/ml) underwent Kirby-Bauer and CLSI antibiotic susceptibility testing. PCR detected virulence genes, Beta-lactamase coding genes, and biofilm-associated resistance genes in E. coli isolates; Out of 200 isolates, 80% comprised Gram-positive and Gram-negative bacteria. Specifically, 120 isolates (60%) were Gram-negative, while 40 isolates (20%) were Gram-positive. Among Gram-negative isolates, 20% were identified as E. coli. Remarkably, all E. coli strains showed resistance to all tested antibiotics, ranging from 80 to 95% resistance. The E. coli isolates harbored three identified resistance genes: blaTEM, blaSHV, and blaCTXM. Regarding biofilm production, 10% showed no formation, 12% weak formation, 62% moderate formation, and 16% strong formation; our study found that pathogenic E. coli caused 20% of UTIs. The majority of studied E. coli strains from UTI patients carried the identified virulence genes, which are vital for infection development and persistence.202439011020
2664130.9997The extended spectrum β-lactamases (ESBL) and virulence genes of intestinal enteroaggregative Escherichia coli (EAEC) in healthy elderly individuals. AIM: to analyze the detection rate of intestinal enteroaggregative Escherichia coli (EAEC) in healthy elderly (≥60 years) individuals in the Hangzhou area of China, and to investigate the extended spectrum β-lactamases and virulence genes of EAEC. METHODS: Stool specimens provided by healthy elderly individuals were cultured on blood agar, SS, and MAC plates. The bacterial strains were identified using Vitek-2 Compact automatic microorganism identification system and mass spectrometry. The resistance phenotypes of the bacteria were determined using the double-disk synergy method. The resistance genes and the EAEC virulence gene, astA and aggR, were amplified by PCR and compared to the sequences available in Gen Bank. RESULTS: Among the 1050 healthy volunteers, the majority of bacteria were E. coli, accounting for 960 strains, with an ESBL-positive rate of 36.3% (348/960). The EAEC detection rate was 10% (96/960); among them, 84 strains were astA, the detection rate of which was 8.75%; 12 strains were aggR, the detection rate of which was 1.25%. The ESBL-positive rate of EAEC strains were 56.25% (54/96), all of which carried the CTX-M type, with the CTX-M-14 predominating at 66.7% (36/54). CONCLUSIONS: The ESBL-positive rate of intestinal E. coli in healthy elderly individuals in the Hangzhou area of China was higher than the rate detected in other regions of china; and there was a high rate of antibiotic resistance among the intestinal EAEC in healthy elderly individuals. The results of this study suggest that EAEC is not only a pathogenic bacteria detected in diarrhea patients, but can also be present in healthy individuals, and high-resistance clinical strains have spread to the healthy population in the Hangzhou area. So vigilance is critical.201526885024
1143140.9997Antimicrobial Resistance and Virulence Profiles of mcr-1-Positive Escherichia coli Isolated from Swine Farms in Heilongjiang Province of China. ABSTRACT: The emergence and global distribution of the mcr-1 gene for colistin resistance have become a public concern because of threats to the role of colistin as the last line of defense against some bacteria. Because of the prevalence of mcr-1-positive Escherichia coli isolates in food animals, production of these animals has been regarded as one of the major sources of amplification and spread of mcr-1. In this study, 249 E. coli isolates were recovered from 300 fecal samples collected from swine farms in Heilongjiang Province, People's Republic of China. Susceptibility testing revealed that 186 (74.70%) of these isolates were colistin resistant, and 86 were positive for mcr-1. The mcr-1-positive isolates had extensive antimicrobial resistance profiles and additional resistance genes, including blaTEM, blaCTX-M, aac3-IV, tet(A), floR, sul1, sul2, sul3, and oqxAB. No mutations in genes pmrAB and mgrB were associated with colistin resistance. Phylogenetic group analysis revealed that the mcr-1-positive E. coli isolates belonged to groups A (52.33% of isolates), B1 (33.72%), B2 (5.81%), and D (8.14%). The prevalence of the virulence-associated genes iutA, iroN, fimH, vat, ompA, and traT was moderate. Seven mcr-1-positive isolates were identified as extraintestinal pathogenic. Among 20 mcr-1-positive E. coli isolates, multilocus sequence typing revealed that sequence type 10 was the most common (five isolates). The conjugation assays revealed that the majority of mcr-1 genes were transferable at frequencies of 7.05 × 10-7 to 7.57 × 10-4. The results of this study indicate the need for monitoring and minimizing the further dissemination of mcr-1 among E. coli isolates in food animals, particularly swine.202032730609
2675150.9997Prevalence and Zoonotic Risk of Multidrug-Resistant Escherichia coli in Bovine Subclinical Mastitis Milk: Insights Into the Virulence and Antimicrobial Resistance. The emergence of antibiotic-resistant microorganisms has made antimicrobial resistance a global issue, and milk is a potential source for the propagation of resistant bacteria causing zoonotic diseases. Subclinical mastitis (SCM) cases, often overlooked and mixed with normal milk in dairy farms, frequently involve E. coli, which can spread through contaminated milk. We conducted this study to determine the prevalence of virulence genes, antibiotic resistance genes (ARGs), antimicrobial susceptibility, and the genetic relatedness of multidrug-resistant (MDR) Shiga toxin-producing E. coli (STEC) isolated from SCM milk. SCM-positive bovine milk was subjected to E. coli detection using cultural, biochemical, and molecular methods. Further, we detected STEC virulence genes including stx1, stx2, and eaeA. STEC isolates were tested for ARGs including blaSHV, CITM, tetA, and aac(3)-IV, and underwent antimicrobial susceptibility tests. Moreover, we performed a phylogenetic analysis of the stx1 gene of MDR-STEC. SCM was detected in 47.2% of milk samples of which 50.54% were E. coli positive. About 17.20% of E. coli isolates contained STEC virulence genes, and stx2 was the most prevalent. Moreover, all STEC isolates harbored at least one of the ARGs, while about 43.75% of the isolates carried multiple ARGs. Additionally, all the STEC isolates showed multidrug resistance, and were found to be fully resistant against amoxicillin, followed by ampicillin (87.50%) and gentamycin (75%); and were mostly sensitive to aztreonam (81.25%) and meropenem (68.75%). In phylogeny analysis, the stx1 gene of isolated MDR-STEC showed close relatedness with disease-causing non-O157 and O157 strains of different sources including cattle, humans, and food.202539816483
2152160.9997Immunological and molecular detection of biofilm formation and antibiotic resistance genes of Pseudomonas aeruginosa isolated from urinary tract. BACKGROUND AND OBJECTIVES: Pseudomonas aeruginosa (P. aeruginosa) is one of the most common causes of hospital-acquired infections. It is associated with high morbidity and healthcare costs, especially when appropriate antibiotic treatment is delayed. Antibiotic selection for patients with P. aeruginosa infections is challenging due to the bacteria's inherent resistance to many commercially available antibiotics. This study investigated antibiotic-resistance genes in isolated bacteria, which play a key role in disease pathogenesis. MATERIALS AND METHODS: 100 samples out of the 140 samples collected from urinary tract infections (UTIs) cases between December 15(th), 2022, and April 15(th), 2023, were included in the study. Identification of bacterial isolates was based on colony morphology, microscopic examination, biochemical tests, and the Vitek-2 system. Antibiotic resistance genes; Aph(3)-llla, ParC, Tet/tet(M), and aac(6´)-Ib-cr were tested by polymerase chain reaction (PCR). RESULTS: The obtained results were based on bacterial identifications of 81 clinical samples. Only 26 (32%) of these isolates were P. aeruginosa, 21 (26%) were Escherichia coli, and 18 (22.2%) were other bacteria. These isolates were used to detect four genes including tet(M), Aph(3)-llla, Par-c, and aac(6´)-Ib-cr. Four types of primers were used for PCR detection. The results showed that 11/14 (78.57%) carried the tet(M) gene, 10/14 (71.42%) carried the Aph(3)-llla gene, 14/14 (100%) carried the Par-c gene, and 10/14 (71.42%) of the isolates carried the aac(6´)-Ib-cr gene. The biofilm formation examining the esp gene, showed that 9 (64.28) isolates carried this gene. CONCLUSION: The inability of antibiotics to penetrate biofilms is an important factor contributing to the antibiotic tolerance of bacterial biofilms.202540612720
2334170.9997High Virulence and Multidrug Resistance of Escherichia coli Isolated in Periodontal Disease. Periodontal disease is caused by different gram-negative anaerobic bacteria; however, Escherichia coli has also been isolated from periodontitis and its role in periodontitis is less known. This study aimed to determine the variability in virulence genotype, antibiotic resistance phenotype, biofilm formation, phylogroups, and serotypes in different emerging periodontal strains of Escherichia coli, isolated from patients with periodontal disease and healthy controls. E. coli, virulence genes, and phylogroups, were identified by PCR, antibiotic susceptibility by the Kirby-Bauer method, biofilm formation was quantified using polystyrene microtiter plates, and serotypes were determined by serotyping. Although E. coli was not detected in the controls (n = 70), it was isolated in 14.7% (100/678) of the patients. Most of the strains (n = 81/100) were multidrug-resistance. The most frequent adhesion genes among the strains were fimH and iha, toxin genes were usp and hlyA, iron-acquisition genes were fyuA and irp2, and protectin genes were ompT, and KpsMT. Phylogroup B2 and serotype O25:H4 were the most predominant among the strains. These findings suggest that E. coli may be involved in periodontal disease due to its high virulence, multidrug-resistance, and a wide distribution of phylogroups and serotypes.202236677337
2971180.9997Characterization of integrons and resistance genes in multidrug-resistant Salmonella enterica isolated from meat and dairy products in Egypt. Foodborne pathogens are a leading cause of illness and death, especially in developing countries. The problem is exacerbated if bacteria attain multidrug resistance. Little is currently known about the extent of antibiotic resistance in foodborne pathogens and the molecular mechanisms underlying this resistance in Africa. Therefore, the current study was carried out to characterize, at the molecular level, the mechanism of multidrug resistance in Salmonella enterica isolated from 1600 food samples (800 meat products and 800 dairy products) collected from different street venders, butchers, retail markets and slaughterhouses in Egypt. Forty-seven out of 69 isolates (68.1%) showed multidrug resistance phenotypes to at least three classes of antimicrobials. The incidence of multidrug-resistant isolates was higher in meat products (37, 69.8%) than in dairy products (10, 62.5%). The multidrug-resistant serovars included, S. enterica serovar Typhimurium (24 isolates, 34.8%), S. enterica serovar Enteritidis, (15 isolates, 21.8%), S. enterica serovar Infantis (7 isolates, 10.1%) and S. enterica non-typable serovar (1 isolate, 1.4%). The highest resistance was to ampicillin (95.7%), then to kanamycin (93.6%), spectinomycin (93.6%), streptomycin (91.5%) and sulfamethoxazole/trimethoprim (91.5%). PCR and DNA sequencing were used to screen and characterize integrons and antibiotic resistance genes and 39.1% and 8.7% of isolates were positive for class 1 and class 2 integrons, respectively. β-lactamase-encoding genes were identified in 75.4% of isolates and plasmid-mediated quinolone resistance genes were identified in 27.5% of isolates. Finally, the florphenicol resistance gene, floR, was identified in 18.8% of isolates. PCR screening identified S. enterica serovar Typhimurium DT104 in both meat and dairy products. This is the first study to report many of these resistance genes in dairy products. This study highlights the high incidence of multidrug-resistant S. enterica in meat and dairy products in Egypt, with the possibility of their transfer to humans leading to therapeutic failure. Therefore, the overuse of antibiotics in animals should be drastically reduced in developing countries.201425113044
2680190.9997Antimicrobial Resistance, Biofilm Formation, and Virulence Genes in Enterococcus Species from Small Backyard Chicken Flocks. Backyard birds are small flocks that are more common in developing countries. They are used for poultry meat and egg production. However, they are also implicated in the maintenance and transmission of several zoonotic diseases, including multidrug-resistant bacteria. Enterococci are one of the most common zoonotic bacteria. They colonize numerous body sites and cause a wide range of serious nosocomial infections in humans. Therefore, the objective of the present study was to investigate the diversity in Enterococcus spp. in healthy birds and to determine the occurrence of multidrug resistance (MDR), multi-locus sequence types, and virulence genes and biofilm formation. From March 2019 to December 2020, cloacal swabs were collected from 15 healthy backyard broiler flocks. A total of 90 enterococci strains were recovered and classified according to the 16S rRNA sequence into Enterococcus faecalis (50%); Enterococcus faecium (33.33%), Enterococcus hirae (13.33%), and Enterococcus avium (3.33%). The isolates exhibited high resistance to tetracycline (55.6%), erythromycin (31.1%), and ampicillin (30%). However, all of the isolates were susceptible to linezolid. Multidrug resistance (MDR) was identified in 30 (33.3%) isolates. The enterococci AMR-associated genes ermB, ermA, tetM, tetL, vanA, cat, and pbp5 were identified in 24 (26.6%), 11 (12.2%), 39 (43.3%), 34 (37.7%), 1 (1.1%), 4 (4.4%), and 23 (25.5%) isolates, respectively. Of the 90 enterococci, 21 (23.3%), 27 (30%), and 36 (40%) isolates showed the presence of cylA, gelE, and agg virulence-associated genes, respectively. Seventy-three (81.1%) isolates exhibited biofilm formation. A statistically significant correlation was obtained for biofilm formation versus the MAR index and MDR. Multi-locus sequence typing (MLST) identified eleven and eight different STs for E. faecalis and E. faecium, respectively. Seven different rep-family plasmid genes (rep1-2, rep3, rep5-6, rep9, and rep11) were detected in the MDR enterococci. Two-thirds (20/30; 66.6%) of the enterococci were positive for one or two rep-families. In conclusion, the results show that healthy backyard chickens could act as a reservoir for MDR and virulent Enterococcus spp. Thus, an effective antimicrobial stewardship program and further studies using a One Health approach are required to investigate the role of backyard chickens as vectors for AMR transmission to humans.202235326843