scholarly journals Prevalence and molecular characterization ofSalmonella entericaisolates throughout an integrated broiler supply chain in China

2016 ◽  
Vol 144 (14) ◽  
pp. 2989-2999 ◽  
Author(s):  
X. REN ◽  
M. LI ◽  
C. XU ◽  
K. CUI ◽  
Z. FENG ◽  
...  

SUMMARYA total of 1145 samples were collected from chicken breeder farms, hatcheries, broiler farms, a slaughterhouse and retail refrigerated chicken stores in an integrated broiler supply chain in Guangdong Province, China, in 2013. One-hundred and twoSalmonella entericastrains were isolated and subjected to serotyping, antimicrobial susceptibility testing, virulence profile determination and molecular subtyping by pulsed field gel electrophoresis (PFGE). The contamination rates in samples from breeder farms, hatcheries, broiler farms, the slaughterhouse and retail stores were 1·46%, 4·31%, 7·00%, 62·86% and 54·67%, respectively. The isolated strains ofS. entericabelonged to 10 serotypes; most of them wereS. Weltevreden (46·08%, 47/102) andS. Agona (18·63%, 19/102). Isolates were frequently resistant to streptomycin (38·2%), tetracycline (36·3%), sulfisoxazole (35·3%) and gentamicin (34·3%); 31·4% of isolates were multidrug resistant. The isolates were screened for 10 virulence factors. TheSalmonellapathogenicity island genesavrA, ssaQ, mgtC, siiD, andsopBand the fimbrial genebcfCwere present in 100% of the strains. PFGE genotyping of the 102S. entericaisolates yielded 24 PFGE types at an 85% similarity threshold. The PFGE patterns show that the genotypes ofS. entericain the production chain are very diverse, but some strains have 100% similarity in different parts of the production chain, which indicates that someS. entericapersist throughout the broiler supply chain.

2012 ◽  
Vol 141 (8) ◽  
pp. 1614-1624 ◽  
Author(s):  
J. DEJLI ◽  
R. A. NADA ◽  
A. MANSOUR ◽  
A. A. EL-MONIEM ◽  
M. O. WASFY ◽  
...  

SUMMARYStrain characteristics of 51Shigella sonneiisolates obtained from children seeking medical care (MC) and 48 isolates recovered during a prospective diarrhoea birth cohort (BC) study were compared. Biochemical characterization and antibiotic susceptibility testing determined that allS. sonneiisolates were biotype g and multidrug-resistant. Plasmid profiling identified 15 closely related patterns andXbaI pulsed-field gel electrophoresis confirmed the high degree of genetic similarity between isolates. AllS.sonneiisolates harbouredipaHand class II integrase genes and 84·3 and 80% of the MC and BC isolates, respectively carried thesengene. Neither the class I integrase nor thesetgene was detected. Our results indicate thatS. sonneiisolates associated with severe diarrhoea were indistinguishable from those associated with mild diarrhoea. Additional genetic tests with greater discrimination might offer an opportunity to determine genetic differences within the globally disseminating biotype g clone.


2019 ◽  
Author(s):  
Tingting Chen ◽  
Jiali Jiang ◽  
Chao Ye ◽  
Jianhua Xie ◽  
Xia Chen ◽  
...  

Abstract Background: Salmonella is one of the most important foodborne pathogens, causing outbreaks of human salmonellosis worldwide. Owing to large scales of consumption markets, pork and poultry that contaminated by Salmonella could pose a tremendous threat to public health. The aim of this study was to investigate the contamination of Salmonella from chicken, pork and the environment in slaughtering and retail processes in Chongqing, China. Results: A total of 115 Salmonella isolates were recovered from 1112 samples collected from pork, chicken and the environment. Compared with the isolation rate of samples from chicken (9.50%) and the environment (6.23%), samples from pork had a significant higher isolation rate (44.00%). The isolation rates in slaughterhouses (10.76%) and in supermarkets (10.07%) showed no statistical different. 30 different serotypes were identified among all the isolates. S. Derby (n=26), S. London (n=16) and S. Rissen (n=12) were the dominant serotypes. Antimicrobial susceptibility testing revealed that 73.04% isolates were resistant to tetracycline, followed by 66.96% to ampicillin and 59.13% to doxycycline. More than half (50.43%) of the isolates were multidrug resistant (MDR), and most of the MDR isolates were from supermarkets. Multilocus sequence typing results showed 24 out of 115 isolates were ST40, which was the most prevalent. Furthermore, isolates from supermarkets had 20 different sequence types while isolates from slaughterhouses only had 8 different sequence types. Conclusion: Our study highlighted that Salmonella was more frequently isolated in pork production chain than that of chicken. Compared with isolates from slaughterhouses, isolates from supermarkets had more MDR profiles and represented a wider range of serotypes and sequence types, indicating that the retail process had more diverse sources of Salmonella contamination than that of slaughtering process.


2012 ◽  
Vol 141 (2) ◽  
pp. 242-250 ◽  
Author(s):  
C. F. KO ◽  
L. Y. WANG ◽  
N. T. LIN ◽  
C. S. CHIOU ◽  
H. C. YEH ◽  
...  

SUMMARYShigella flexneri 4a caused sustained outbreaks in a large long-stay psychiatric centre, Taiwan, 2001–2006. Trimethoprim-sulphamethoxazole (SXT) prophylaxis was administered in 2004. We recovered 108 S. flexneri 4a isolates from 83 symptomatic (including one caregiver) and 12 asymptomatic subjects (11 contacts, one caregiver). The isolates were classified into eight antibiogram types and 15 genotypes (six clusters) by using antimicrobial susceptibility testing and pulsed-field gel electrophoresis of NotI-digested DNA, respectively. These characteristics altered significantly after SXT prophylaxis (P < 0·05), with concomitant emergence of SXT-resistant isolates in two antibiogram types. P01 (n = 71), the predominant epidemic genotype, caused infection in two caregivers and five patients under their care; two P01 isolates were recovered from the same patient 6 months apart. These results indicate the importance of sustained person-to-person transmission of S. flexneri 4a by long-term convalescent, asymptomatic or caregiver carriers, and support the emergence of SXT-resistant strains following selective pressure by SXT prophylaxis.


2016 ◽  
Vol 79 (8) ◽  
pp. 1418-1423
Author(s):  
M. FONTCUBERTA ◽  
R. PLANELL ◽  
A. TORRENTS ◽  
S. SABATÉ ◽  
R. GONZALEZ ◽  
...  

ABSTRACT The main purpose of this study was to determine the prevalence of Escherichia coli O157 on bovine carcasses before and after chilling at a large slaughterhouse located in the city of Barcelona, Spain, to assess the effectiveness of dry chilling on reducing E. coli O157 contamination of carcasses. In addition, the study characterized the E. coli O157 strains isolated in terms of virulence factors, antibiotic susceptibility, and their genetic diversity. Individual bovine carcasses were sampled before (n = 300) and after (n = 300) chilling over an 8-month period. Positive samples for E. coli O157 were subjected to virulence screening by PCR (stx1, stx2, and eaeA genes and the fliCH7 gene), antimicrobial susceptibility testing, and molecular typing by pulsed-field gel electrophoresis. A total of 9.7% (29 of 300) of the nonrefrigerated carcasses examined and 2.3% (7 of 300) of the refrigerated carcasses were positive for E. coli O157. All the isolates were serotype O157:H7, 92% (33 of 36) carried the stx1, stx2, and eaeA genes, and 8% (3 of 36) carried the stx2 and eaeA genes. Antimicrobial susceptibility testing showed a high degree of resistance: 29 strains (81%) were resistant to at least 1 antimicrobial of the 12 antimicrobials tested; 69% (25 of 36) were resistant to 4 or more antimicrobials. Molecular typing by pulsed-field gel electrophoresis found a high diversity of genetic types, implying little cross-contamination in the slaughterhouse. This study confirms that E. coli O157:H7 is present on the carcasses slaughtered in Spain, although its prevalence is reduced by the dry chilling process used. The recovered isolates showed potential pathogenesis and a high degree of multidrug resistance, confirming the importance of bovine meat monitoring.


2013 ◽  
Vol 781-784 ◽  
pp. 1332-1335
Author(s):  
Tao Yu

Listeria monocytogenes isolates recovered from retail foods were characterized by serotyping, genotyping using pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. Six serotypes were identified among the isolates and the predominant serotype was 1/2a (42, 48.8%). PFGE differentiated the 86 isolates into 23 ApaI restriction patterns. Twenty-five (29.1%) of the L.monocytogenes strains exhibited resistance to at least one antimicrobial. Resistance to ciprofloxacin (17.4% of the isolates were resistant) and resistance to tetracycline (17.4%) were observed frequently.


2017 ◽  
Vol 71 (1) ◽  
pp. 0-0
Author(s):  
Patrycja Zalas-Więcek ◽  
Tomasz Bogiel ◽  
Krzysztof Wiśniewski ◽  
Eugenia Gospodarek-Komkowska

Introduction: The aim of the study was to evaluate genetic relatedness and antimicrobial susceptibility of extended-spectrum beta-lactamase-producing E. coli strains isolated from patients hospitalized in the University Hospital in Bydgoszcz (Poland).Material and methods: The study included 33 extended-spectrum beta-lactamase-producing E. coli strains isolated from 31 patients. The chromosomal DNA was extracted from the strains and separated by pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was performed by the agar dilution method and carried out according to the European Committee on Antimicrobial Susceptibility Testing recommendations.Results: According to the pulsed-field gel electrophoresis results, 32 distinct pulsotypes were revealed. Based on Molecular Analyst Fingerprinting software analysis, the studied isolates were divided into four subgroups: 6 (18.2%) isolates showing similarity greater than 90% (group A); 19 (57.6%) showing 80-90% similarity (group B); 7 (21.2%) showing 70-79% similarity (group C); and one isolate with less than 70% similarity (group D). Among E. coli isolates showing similarity greater than 90%, four antimicrobial patterns were noted. Among the isolates showing 80-90% similarity, 18 antimicrobial patterns were observed. E. coli isolates showing 70-79% similarity presented 6 antimicrobial patterns.Conclusions: Our results show a high degree of genetic diversity of extended-spectrum beta-lactamase-producing E. coli isolates. However, based on a similarity of ≥80%, almost 75% of E. coli isolates were clonally related. Although it is difficult to identify definitive transmission events based on the recovery of indistinguishable pulsed-field gel electrophoresis types alone, we speculate that extended-spectrum beta-lactamase-producing E. coli strains may have disseminated throughout the hospital.


AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Quan Li ◽  
Jian Yin ◽  
Zheng Li ◽  
Zewei Li ◽  
Yuanzhao Du ◽  
...  

AbstractSalmonella is an important food-borne pathogen associated with public health and high economic losses. To investigate the prevalence and the characteristics of Salmonella in a pig slaughterhouse in Yangzhou, a total of 80 Salmonella isolates were isolated from 459 (17.43%) samples in 2016–2017. S. Derby (35/80, 43.75%) was the most prevalent, followed by S. Rissen (16/80, 20.00%) and S. Newlands (11/80, 13.75%). The highest rates of susceptibility were observed to cefoxitin (80/80, 100.0%) and amikacin (80/80, 100.0%), followed by aztreonam (79/80, 98.75%) and nitrofurantoin (79/80, 98.75%). The highest resistance rate was detected for tetracycline (65/80, 81.25%), followed by ampicillin (60/80, 75.00%), bactrim (55/80, 68.75%), and sulfisoxazole (54/80, 67.50%). Overall, 91.25% (73/80) of the isolates were resistant to at least one antibiotic, while 71.25% (57/80) of the isolate strains were multidrug resistant in the antimicrobial susceptibility tested. In addition, 86.36% (19/22) of the 22 antimicrobial resistance genes in the isolates were identified. Our data indicated that the resistance to certain antimicrobials was significantly associated, in part, with antimicrobial resistance genes. Furthermore, 81.25% (65/80) isolates harbored the virulence gene of mogA, of which 2 Salmonella Typhimurium isolates carried the mogA, spvB and spvC virulence genes at the same time. The results showed that swine products in the slaughterhouse were contaminated with multidrug resistant Salmonella commonly, especially some isolates carry the spv virulence genes. The virulence genes might facilitate the dissemination of the resistance genes to consumers along the production chain, suggesting the importance of controlling Salmonella during slaughter for public health.


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