scholarly journals Antimicrobial Resistance, Virulence Factors, and Genetic Profiles ofVibrio parahaemolyticusfrom Seafood

2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Magdalena Lopatek ◽  
Kinga Wieczorek ◽  
Jacek Osek

ABSTRACTVibrio parahaemolyticusis a widespread bacterium in the marine environment and is responsible for gastroenteritis in humans. Foodborne infections are mainly associated with the consumption of contaminated raw or undercooked fish and shellfish. The aim of this study was to determine the antimicrobial resistance, virulence factors, and genetic profiles ofV. parahaemolyticusisolates from seafood originating from different countries. A total of 104 (17.5%) isolates were recovered from 595 analyzed samples. The isolates were tested for the presence of thetdhandtrhgenes, involved in the pathogenesis ofV. parahaemolyticusinfections in humans, and these genes were detected in 3 (2.9%) and 11 (10.6%) isolates, respectively. Thetrh-positive isolates also possessed theuregene, which is responsible for urease production. Moreover, the activity of protease A was identified in allV. parahaemolyticusstrains. Antimicrobial resistance revealed that most isolates were resistant to ampicillin (75.0%) and streptomycin (68.3%), whereas all strains were sensitive to chloramphenicol and tetracyclines. Most of the isolates (55.8%) showed resistance against two classes of antimicrobials, mainly to ampicillin and streptomycin (46.2%). Only one isolate displayed a multiresistant pattern. Genotypic analysis ofV. parahaemolyticusrevealed a high degree of diversity among the isolates tested. The pulsed-field gel electrophoresis (PFGE) method distinguished 73 clonal groups, and the most numerous group consisted of 7 strains. Sequencing by the multilocus sequence typing (MLST) method showed 76 sequence types (STs), of which ST481 and ST1361 were most frequently identified. In addition, 51 (67.1%) new sequence types were discovered and added to the PubMLST international database.IMPORTANCEThe presence ofV. parahaemolyticusin seafood may pose a risk for consumers, especially in countries where shellfish are eaten raw. In recent years, a significant increase of food poisoning caused by these bacteria has been also observed in Europe. Our results highlight the high level ofV. parahaemolyticuscontamination of seafood, along with the isolates being potentially pathogenic for humans. However, the first-line antimicrobials, such as tetracyclines and fluoroquinolones, remained highly effective againstV. parahaemolyticus. The monitoring of antimicrobial resistance of isolates is important to ensure the high efficacy in the treatment of human infections. Most ofV. parahaemolyticusstrains possessed new sequence types (STs), which showed the high genetic diversity of the isolates tested.

2020 ◽  
Vol 8 (2) ◽  
pp. 222 ◽  
Author(s):  
Guido Di Donato ◽  
Francesca Marotta ◽  
Roberta Nuvoloni ◽  
Katiuscia Zilli ◽  
Diana Neri ◽  
...  

Campylobacter spp. are among the microorganisms most commonly associated with foodborne disease. Swine are known to be the main reservoir of Campylobacter coli and a possible source infection of humans as a result of carcass contamination at slaughter. The aim of this study was to evaluate the prevalence of C. coli contamination in swine carcasses, the antimicrobial resistance (AMR) patterns of isolates and the genetic diversity between strains obtained from swine and those isolated from humans. The prevalence of contamination was higher on carcasses (50.4%) than in faeces (32.9%). The 162 C. coli isolated from swine were examined by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The results of PFGE indicated a high genetic diversity among the isolates, with 25 different PFGE types. MLST assigned 51 sequence types (STs) to isolates. The most common genotype was ST-854 (16.04%), ST-9264 (10.49 %) and ST-1016 (6.08 %). Results of AMR showed a high resistance to quinolones and fluoroquinolones together with aminoglycosides and tetracycline. Many strains were multi-resistant with predominant R-type TeSCipNa (57%). Five resistance genes were detected along with mutation in the gyrA gene. A strong correlation between phenotypic and genotypic resistance was found for fluoroquinolone and tetracycline. Genetic profiles obtained in swine isolates were compared to those of 11 human strains. All human strains and 64.19% of animal strains (104/162) were assigned to the ST-828 clonal complex.


2014 ◽  
Vol 53 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Walter Demczuk ◽  
Tarah Lynch ◽  
Irene Martin ◽  
Gary Van Domselaar ◽  
Morag Graham ◽  
...  

A large-scale, whole-genome comparison of CanadianNeisseria gonorrhoeaeisolates with high-level cephalosporin MICs was used to demonstrate a genomic epidemiology approach to investigate strain relatedness and dynamics. Although current typing methods have been very successful in tracing short-chain transmission of gonorrheal disease, investigating the temporal evolutionary relationships and geographical dissemination of highly clonal lineages requires enhanced resolution only available through whole-genome sequencing (WGS). Phylogenomic cluster analysis grouped 169 Canadian strains into 12 distinct clades. While someN. gonorrhoeaemultiantigen sequence types (NG-MAST) agreed with specific phylogenomic clades or subclades, other sequence types (ST) and closely related groups of ST were widely distributed among clades. Decreased susceptibility to extended-spectrum cephalosporins (ESC-DS) emerged among a group of diverse strains in Canada during the 1990s with a variety of nonmosaicpenAalleles, followed in 2000/2001 with thepenAmosaic X allele and then in 2007 with ST1407 strains with thepenAmosaic XXXIV allele. Five genetically distinct ESC-DS lineages were associated withpenAmosaic X, XXXV, and XXXIV alleles and nonmosaic XII and XIII alleles. ESC-DS with coresistance to azithromycin was observed in 5 strains with 23S rRNA C2599T or A2143G mutations. As the costs associated with WGS decline and analysis tools are streamlined, WGS can provide a more thorough understanding of strain dynamics, facilitate epidemiological studies to better resolve social networks, and improve surveillance to optimize treatment for gonorrheal infections.


Author(s):  
Nireshni Mitchev ◽  
Ravesh Singh ◽  
Mushal Allam ◽  
Stanford Kwenda ◽  
Arshad Ismail ◽  
...  

Objective: Antimicrobial resistance (AMR) is a major challenge to managing infectious diseases. Africa has the highest incidence of gonorrhoea but there is a lack of comprehensive data from sparse surveillance programs. This study investigated the molecular epidemiology and AMR profiles of Neisseria gonorrhoeae isolates in KwaZulu-Natal province (KZN), South Africa. Methods: Repository isolates, from patients attending public healthcare clinics for STI care, were used for phenotypic and genotypic analysis. Etest® was performed to determine antimicrobial susceptibility. Whole-genome sequencing (WGS) was used to determine epidemiology and to predict susceptibility by detecting resistance-associated genes and mutations. Results: Among the 61 isolates, multiple sequence types were identified. Six isolates were novel as determined by multilocus sequence typing. N.gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) determined 48 sequence types, of which 35 isolates had novel antimicrobial profiles. Two novel penA alleles and eight novel mtrR alleles were identified. Point mutations were detected in gyrA , parC , mtrR , penA , ponA and porB1 . This study revealed a high prevalence of AMR (penicillin 67%, tetracycline 89% and ciprofloxacin 52%). However, spectinomycin, cefixime, ceftriaxone and azithromycin remained 100% effective. Conclusion: This study is one of the first to comprehensively describe the epidemiology and AMR of N. gonorrhoeae in KZN, South Africa and Africa, using WGS. KZN has a wide strain diversity and most of these sequence types have been detected in multiple countries, however more than half of our isolates have novel antimicrobial profiles. Continued surveillance is crucial to monitor the emergence of resistance to cefixime, ceftriaxone and azithromycin.


Author(s):  
Geoffrey W Coombs ◽  
Denise A Daley ◽  
Shakeel Mowlaboccus ◽  
Yung Thin Lee ◽  
Stanley Pang ◽  
...  

From 1 January to 31 December 2018, thirty-six institutions around Australia participated in the Australian Enterococcal Sepsis Outcome Programme (AESOP). The aim of AESOP 2018 was to determine the proportion of enterococcal bacteraemia isolates in Australia that were antimicrobial resistant, and to characterise the molecular epidemiology of the E. faecium isolates. Of the 1,248 unique episodes of bacteraemia investigated, 93.5% were caused by either E. faecalis (54.2%) or E. faecium (39.3%). Ampicillin resistance was not detected in E. faecalis but was detected in 89.4% of E. faecium. Vancomycin non-susceptibility was not detected in E. faecalis but was reported in 45.0% of E. faecium. Overall 49.3% of E. faecium isolates harboured vanA or vanB genes. Of the vanA/vanB positive E. faecium isolates, 52.9% harboured vanA genes and 46.2% vanB genes; 0.8% harboured both vanA and vanB genes. The percentage of E. faecium bacteraemia isolates resistant to vancomycin in Australia is substantially higher than that seen in most European countries. E. faecium consisted of 59 multilocus sequence types (STs) of which 74.4% of isolates were classified into six major STs containing ten or more isolates. All major STs belong to clonal cluster (CC) 17, a major hospital-adapted polyclonal E. faecium cluster. The predominant STs (ST17, ST1424, ST796, ST80, ST1421, and ST262) were found across most regions of Australia. The most predominant clone was ST17 which was identified in all regions except the Australian Capital Territory and the Northern Territory. Overall, 55.8% of isolates belonging to the six predominant STs harboured vanA or vanB genes. The AESOP 2018 study has shown that enterococcal bacteraemias in Australia are frequently caused by polyclonal ampicillin-resistant high-level gentamicin-resistant vanA- or vanB-harbouring E. faecium which have limited treatment options.


2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Tessa E. LeCuyer ◽  
Barbara A. Byrne ◽  
Joshua B. Daniels ◽  
Dubraska V. Diaz-Campos ◽  
G. Kenitra Hammac ◽  
...  

ABSTRACTEscherichia coliis the most common cause of human and canine urinary tract infection (UTI). Clonal groups, often with high levels of antimicrobial resistance, are a major component of theE. colipopulation that causes human UTI. While little is known about the population structure ofE. colithat causes UTI in dogs, there is evidence that dogs and humans can share fecal strains ofE. coliand that human-associated strains can cause disease in dogs. In order to better characterize theE. colistrains that cause canine UTI, we analyzed 295E. coliisolates obtained from canine urine samples from five veterinary diagnostic laboratories and analyzed their multilocus sequence types, phenotypic and genotypic antimicrobial resistance profiles, and virulence-associated gene repertoires. Sequence type 372 (ST372), an infrequent human pathogen, was the predominant sequence type in dogs at all locations. Extended-spectrum β-lactamase-producing isolates withblaCTX-Mgenes were uncommon in canine isolates but when present were often associated with sequence types that have been described in human infections. This provides support for occasional cross-host-species sharing of strains that cause extraintestinal disease and highlights the importance of understanding the role of companion animals in the overall transmission patterns of extraintestinal pathogenicE. coli.


2018 ◽  
Vol 200 (15) ◽  
Author(s):  
Carlos R. Osorio ◽  
Ana Vences ◽  
Xosé M. Matanza ◽  
Mateus S. Terceti

ABSTRACTPhotobacterium damselaesubsp.damselaecauses vibriosis in a variety of marine animals, including fish species of importance in aquaculture. It also may cause wound infections in humans that can progress to a fatal outcome. Two major virulence factors are encoded within the large conjugative plasmid pPHDD1, the phospholipase D damselysin (Dly) and the pore-forming toxin phobalysin P (PhlyP). The two toxins exert hemolytic and cytolytic activities in a synergistic manner. Even though PhlyP has close homologues in manyVibriospecies, it has unique features that differentiate it from related toxins. Dly phospholipase constitutes a singular trait ofP. damselaesubsp.damselaeamong theVibrionaceae, although related toxins are found in members of theAeromonadaceae. Fish farm outbreaks can also be caused by plasmidless strains. Such observations led to the characterization of two ubiquitous chromosome-encoded toxins with lesser cytolytic activity, the pore forming-toxin phobalysin C (PhlyC) and the phospholipase-hemolysin PlpV. The high genetic diversity of this pathogen deserves special attention, as it has a number of strain-specific features, including the cell envelope polysaccharide synthesis clusters. Fish outbreaks are likely caused by multiclonal populations which contain both plasmidless and pPHDD1-harboring isolates and not by well-adapted clonal complexes. Still, among such genetic heterogeneity, it is feasible to identify conserved weak points in the biology of this bacterium: the two-component regulatory system RstAB (CarSR) was found to be necessary for the maximal production of virulence factors, and its inactivation severely impaired virulence.


mSystems ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Chaofang Zhong ◽  
Maozhen Han ◽  
Pengshuo Yang ◽  
Chaoyun Chen ◽  
Hui Yu ◽  
...  

ABSTRACT The genus Aeromonas is a common gastrointestinal pathogen associated with human and animal infections. Due to the high level of cross-species similarity, their evolutionary dynamics and genetic diversity are still fragmented. Hereby, we investigated the pan-genomes of 29 Aeromonas species, as well as Aeromonas species in microbial communities, to clarify their evolutionary dynamics and genetic diversity, with special focus on virulence factors and horizontal gene transfer events. Our study revealed an open pan-genome of Aeromonas containing 10,144 gene families. These Aeromonas species exhibited different functional constraints, with the single-copy core genes and most accessory genes experiencing purifying selection. The significant congruence between core genome and pan-genome trees revealed that core genes mainly affected evolutionary divergences of Aeromonas species. Gene gains and losses revealed a high level of genome plasticity, exhibited by hundreds of gene expansions and contractions, horizontally transferred genes, and mobile genetic elements. The selective constraints shaped virulence gene pools of these Aeromonas strains, where genes encoding hemolysin were ubiquitous. Of these strains, Aeromonas aquatica MX16A seemed to be more resistant, as it harbored most resistance genes. Finally, the virulence factors of Aeromonas in microbial communities were quite dynamic in response to environment changes. For example, the virulence diversity of Aeromonas in microbial communities could reach levels that match some of the most virulent Aeromonas species (such as A. hydrophila) in penetrated-air and modified-air packaging. Our work shed some light onto genetic diversity, evolutionary history, and functional features of Aeromonas, which could facilitate the detection and prevention of infections. IMPORTANCE Aeromonas has long been known as a gastrointestinal pathogen, yet it has many species whose evolutionary dynamics and genetic diversity had been unclear until now. We have conducted pan-genome analysis for 29 Aeromonas species and revealed a high level of genome plasticity exhibited by hundreds of gene expansions and contractions, horizontally transferred genes, and mobile genetic elements. These species also contained many virulence factors both identified from single isolated species and microbial community. This pan-genome study could elevate the level for detection and prevention of Aeromonas infections.


2019 ◽  
Vol 7 (11) ◽  
pp. 579 ◽  
Author(s):  
Jae-Ho Guk ◽  
Junhyung Kim ◽  
Hyokeun Song ◽  
Jinshil Kim ◽  
Jae-Uk An ◽  
...  

Campylobacter, a common foodborne human pathogen, is considered sensitive to oxygen. Recently, aerotolerant (AT) Campylobacter jejuni with the ability to survive under aerobic stress has been reported. Here, we investigated the prevalence of hyper-aerotolerant (HAT) Campylobacter coli from duck sources (118 carcasses and meat) and its characteristics to assess potential impacts on public health. Half of 56 C. coli isolates were HAT and most harbored various virulence genes including flaA, cadF, cdtA, ceuB, and wlaN. Moreover, 98.2% of C. coli isolates showed resistance to quinolones, including ciprofloxacin (CIP), and nine (16.1%) showed high-level resistance to ciprofloxacin (Minimum Inhibitory Concentration, MIC ≥ 32 μg/mL) and most of these were HAT. Based on genetic relatedness between C. coli from duck sources and those from human sources (PubMLST and NCBI), HAT isolates sharing the same MLST sequence types were significantly more prevalent than those not sharing the same sequence types as those from human sources. Therefore, HAT C. coli is prevalent in duck sources, and is most likely transmitted to humans through the food chain given its aerotolerance. This being so, it might pose a threat to public health given its virulence and antimicrobial resistance (AMR). This study will assist in improving control strategies to reduce farm-to-table HAT C. coli transmission to humans.


2021 ◽  
Vol 87 (10) ◽  
Author(s):  
Terence Lee ◽  
David Jordan ◽  
Shafi Sahibzada ◽  
Rebecca Abraham ◽  
Stanley Pang ◽  
...  

ABSTRACT Enterococci are ubiquitous opportunistic pathogens that have become a major public health issue globally. The increasing prevalence of antimicrobial resistance in hospital-adapted enterococci had been thought to originate from livestock. However, this association between livestock and hospital-adapted enterococci is currently unclear. This study investigates the antimicrobial susceptibilities of enterococci isolated from pig cecal samples and compares the genomic characteristics of Enterococcus faecium from pigs to those of isolates from meat chickens and from human sepsis cases. From 200 cecal samples, antimicrobial susceptibility testing was performed for E. faecium (n = 84), E. hirae (n = 36), and E. faecalis (n = 17). Whole-genome sequencing was performed for all E. faecium isolates, and the sequences were compared to those of previously studied isolates from meat chickens and human sepsis cases through bioinformatics analysis. Resistance (non-wild type) to erythromycin, gentamicin, tetracycline, ampicillin, daptomycin, virginiamycin, and quinupristin-dalfopristin was identified. More importantly, except for a single isolate harboring the vanC operon, no resistance was observed in the three species to vancomycin, teicoplanin, and linezolid, which are critically important antimicrobials used to treat enterococcal infections in humans. The E. faecium isolates from chickens were genetically distinct from human and pig isolates, which were more closely related. Human strains that were closely related to pig strains were not typical “hospital-adapted strains” as previously identified. The results of this study show that enterococci from Australian finisher pigs are not a source of resistance to critically important antimicrobials and that E. faecium from pigs is not part of the current human hospital-adapted population. IMPORTANCE Resistance to the critically important antimicrobials vancomycin, teicoplanin, and linezolid is not found in enterococci collected from Australian finisher pigs. However, some antimicrobial resistance was observed. In particular, resistance to quinupristin-dalfopristin, a combination of two streptogramin class antimicrobials, was identified despite the absence of streptogramin use Australia-wide since 2005. Other observed resistance among enterococci from pigs include chloramphenicol, erythromycin, and tetracycline resistance. Genomic comparison of E. faecium from Australian pigs to isolates collected from previous studies on chickens and humans indicate that E. faecium from pigs are genetically more similar to those of humans than those from chickens. Despite the increased genetic similarities, E. faecium strains from pigs are phylogenetically distinct and did not belong to the dominant sequence types found in hospital-adapted strains causing sepsis in humans. Therefore, the results indicate that Australian finisher pigs are not a source of hospital-adapted E. faecium in Australia.


2021 ◽  
Vol 7 (11) ◽  
Author(s):  
Ka Lip Chew ◽  
Sophie Octavia ◽  
Roland Jureen ◽  
Oon Tek Ng ◽  
Kalisvar Marimuthu ◽  
...  

Mycobacterium abscessus comprises three subspecies: M. abscessus subsp. abscessus , M. abscessus subsp. bolletii , and M. abscessus subsp. massiliense . These closely related strains are typically multi-drug-resistant and can cause difficult-to-treat infections. Dominant clusters of isolates with increased pathogenic potential have been demonstrated in pulmonary infections in the global cystic fibrosis (CF) population. An investigation was performed on isolates cultured from an Asian, predominantly non-CF population to explore the phylogenomic relationships within our population and compare it to global M. abscessus isolates. Whole-genome-sequencing was performed on M. abscessus isolates between 2017 and 2019. Bioinformatic analysis was performed to determine multi-locus-sequence-type, to establish the phylogenetic relationships between isolates, and to identify virulence and resistance determinants in these isolates. A total of 210 isolates were included, of which 68.5 % (144/210) were respiratory samples. These isolates consisted of 140 (66.6 %) M . abscessus subsp. massiliense , 67 (31.9 %) M . abscessus subsp. abscessus, and three (1.4 %) M . abscessus subsp. bolletii . Dominant sequence-types in our population were similar to those of global CF isolates, but SNP differences in our population were comparatively wider despite the isolates being from the same geographical region. ESX (ESAT-6 secretory) cluster three appeared to occur most commonly in ST4 and ST6 M. abscessus subsp. massiliense , but other virulence factors did not demonstrate an association with isolate subspecies or sample source. We demonstrate that although similar predominant sequence-types are seen in our patient population, cross-transmission is absent. The risk of patient-to-patient transmission appears to be largely limited to the vulnerable CF population, indicating infection from environmental sources remains more common than human-to-human transmission. Resistance and virulence factors are largely consistent across the subspecies with the exception of clarithromycin susceptibility and ESX-3.


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