Serogroups O1 Research Articles

The relationship between phylogenetic classification, virulence and antibiotic resistance of extraintestinal pathogenic Escherichia coli in İzmir province, Turkey

BackgroundExtraintestinal pathogenic Escherichia coli (ExPEC) is an important bacterium and responsible for many bloodstream infections, including urinary tract infections and even fatal bacteremia. The aim of this research was to investigate whether ExPEC strains isolated from Turkish blood cultures have a relationship between 16S rRNA based phylogenetic clusters and antibiotic resistance profiles, virulence factors or clonal lineages.MethodsPhenotypically identified ExPEC blood culture isolates (n = 104) were included in this study. The 16S rRNA partial sequence analysis was performed for genotypic identification of ExPEC isolates. Antibiotic susceptibility and Extended-Spectrum β-Lactamase testing of isolates were performed. Phylogenetic classification (A, B1, B2 and D), Multi Locus Sequence Typing analysis and virulence-associated genes were investigated.ResultsBased on 16S rRNA partial sequence analysis, 97 out of 104 (93.26%) ExPEC isolates were confirmed as E. coli. Ampicillin (74.22%) and cefuroxime axetil (65.97%) resistances had the highest frequencies among the ExPEC isolates. In terms of phylogenetic classification of ExPEC, D (38.14%, 37/97) was the most prevalent group after A (29.89%, 29/97), B2 (20.61%, 20/97), and B1 (11.34%, 11/97). The sequence types of the 20 ExPEC isolates belonging to the B2 phylogenetic group were analyzed by Multi Locus Sequence Typing. Ten isolates out of 20 (50.0%) were identified as ST131. The other STs were ST95 (n = 1), ST14 (n = 1), ST10 (n = 1), ST69 (n = 1), ST1722 (n = 2), ST141 (n = 1), ST88 (n = 1), ST80 (n = 1), and ST998 (n = 1). Of the ST131 strains, six (60%, 6/10) represented serogroup O25. The most common virulence factor genes were serum resistance factor gene, traT (55.7%) aerobactin siderophore receptor and yersiniabactin encoding genes iutA (45.3%) and fyuA (50.5%), respectively. In addition, PAI (41.2%), iroN (23.7%), hlyA (15.4%), kpsII (13.4%), ompT (13.4%), papG (12.4%), iss (9.3%), cnf1 (7.2%), ibeA (2.06%), and sfaS (2.06%) genes were present in the ExPEC isolates.ConclusionThe 16S rRNA-based phylogenetic relationship tree analysis showed that a large cluster was present among 97 ExPEC isolates along with related reference strains. There were 21 main clusters with 32 closely related subclusters. Based on our findings, different clonal lineages of ExPEC can display different antibiotic susceptibilities and virulence properties. We also concluded that virulence factors were not distributed depending on phylogenetic groups (A, B1, B2, and D). The ExPEC isolates belonging to the same phylogenetic group and sequence type could display different resistance and virulence characteristics.

Multi-drug resistant Escherichia coli in diarrhoeagenic foals: Pulsotyping, phylotyping, serotyping, antibiotic resistance and virulence profiling

Extraintestinal pathogenic E. coli (ExPEC) possess the ability to cause extraintestinal infections such as urinary tract infections, neonatal meningitis and sepsis. While information is readily available describing pathogenic E. coli populations in food-producing animals, studies in companion/sports animals such as horses are limited. In addition, many antimicrobial agents used in the treatment of equine infections are also utilised in human medicine, potentially contributing to the spread of antibiotic resistance determinants among pathogenic strains. The aim of this study was to phenotypically and genotypically characterise the multidrug resistance and virulence associated with 83 equine E. coli isolates recovered from foals with diarrhoeal disease. Serotyping was performed by both PCR and sequencing. Antibiotic resistance was assessed by disc diffusion. Phylogenetic groups, virulence genes, antibiotic resistance genes and integrons were determined by PCR. Thirty-nine (46%) of the isolates were classified as ExPEC and hence considered to be potentially pathogenic to humans and animals. Identified serogroups O1, O19a, O40, O101 and O153 are among previously reported human clinical ExPEC isolates. Over a quarter of the E. coli were assigned to pathogenic phylogroups B2 (6%) and D (23%). Class 1 and class 2 integrons were detected in 85% of E. coli, revealing their potential to transfer MDR to other pathogenic and non-pathogenic bacteria. With 65% of potentially pathogenic isolates harbouring one or more TEM, SHV and CTX-M-2 group β-lactamases, in addition to the high levels of resistance to fluoroquinolones observed, our findings signal the need for increased attention to companion/sport animal reservoirs as public health threats.

Risk factors associated with E. coli causing neonatal calf diarrhea.

Calf diarrhea is one of the major health challenges in cattle herds. The bacteriological examination of fecal samples collected from apparently healthy and diarrheic calves' revealed isolation of 26 E. coli isolates out of 56 calves with an incidence of 46.4%. Serogroups O1, O26, O44, O55, O115, O119, O125, O146, and O151 were identified from the collected fecal samples. Using PCR all isolates was positive for ompA gene species specific for E. coli. While stx1 and eaeA genes detected with incidence of 3.8 and 19.2% respectively from the isolates. The presence of stx2 gene was negative in the fecal isolates. Among colostrum samples 4 E. coli isolates were detected and serogrouped to O26, O55 and O119. They were negative for eaeA, stx1 and stx2 except strain number 4 (O55) was positive for stx1. E. coli strains were sensitive to norfloxacin (80.7%) and resistant to ampicillin and cefotaxime (100% each). Based on our findings, there was no association between occurrence of E. coli and age of calf (2–14 days), while bottle feeding calf colostrum may be a source of E. coli contamination.

Virulence properties of uropathogenic Escherichia coli isolated from children with urinary tract infection in Korea.

Urinary tract infections (UTIs) are one of the most common types of bacterial infection in humans in various parts of the world and are caused mainly by uropathogenic Escherichia coli (UPEC). A total of 58 UPEC isolates from urine were characterized by serotyping and pulsed-field gel electrophoresis (PFGE). The majority of the UPEC strains belonged to serogroups O2 and O6. The UPEC strains were grouped under different pulsotypes and majority of them belonged to serogroups O2 and O6. Among the 14 virulence factors considered, 13 were present in various serogroups. The virulence genes fimH and sfa were present in all the isolates while none of the isolates carried lt-1. The strains exhibited 36 different virulence patterns, of which 11, referred to as UP (UPEC pattern) 1 to UP 11 were most common. Antibiotic resistance profiling of the UPEC isolates revealed that the serogroups O2 and O6 contain the highest number of resistant strains. The data from the current study depicting the distribution of UPEC strains among various serogroups and pulsotypes, and the occurrence of virulence genes and antibiotics resistance offer useful information on the epidemiological features of UPEC in Korea for the enhanced surveillance of potential emergence of UPEC.

A bivalent vaccine derived from attenuated Salmonella expressing O-antigen polysaccharide provides protection against avian pathogenic Escherichia coli O1 and O2 infection

Avian pathogenic Escherichia coli (APEC), a leading cause of avian airsacculitis and colibacillosis, is responsible for significant economic loss in the poultry industry. APEC serogroups O1, O2, and O78 are predominantly associated with disease. Lipopolysaccharide (LPS) O-antigen has been shown to be a potent antigen for inducing specific protective immune responses. Therefore, we sought to develop a multivalent polysaccharide vaccine to prevent most APEC infections. We previously reported the stable expression of plasmid pSS27 encoding the APEC O1 O-antigen gene cluster (10.8 kb) in attenuated Salmonella enterica serovar Typhimurium S740 provided excellent protection against APEC O1 challenge. In this study, the plasmid pSS28 harboring the APEC O2 O-antigen polysaccharide gene cluster (15.5 kb) was constructed. Biosynthesis of pSS28-encoded APEC O2 O-antigen in Salmonella vaccine strain S740 was validated by Western blot. The recombinant Salmonella vaccine strain S740 (pSS28) elicited homologous protection against virulent wild-type APEC O2 challenge in a chicken model. Furthermore, through equal-volume mixing the two monovalent vaccine strains S740 (pSS27) and S740 (pSS28), a bivalent vaccine candidate against both APEC O1 and O2 was developed. Immunization of chickens with the bivalent vaccine elicited production of serum IgG and mucosal sIgA antibodies against the LPS of both APEC O1 and O2. Moreover, antibodies induced by the bivalent vaccine promoted opsonization, provoked complement-mediated bactericidal activity, and elicited protection against lethal challenge with both virulent APEC O1 and O2 strains. These results demonstrate that the bivalent vaccine comprised of S740 (pSS27) and S740 (pSS28) is a promising vaccine candidate against APEC O1 and O2 infection.

Evaluation of cholera surveillance system in Ga South Municipality, Greater Accra Region, Ghana, 2016

Introduction : cholera is an acute illness with profuse watery diarrhea with high case fatality rate is left untreated. It is caused by Vibrio cholera serogroups O1 or O139. The disease is transmitted fecal-orally through ingesting contaminated food or water. In 2014, 16,527 cases including 128 deaths (CFR 0.8%) were reported from 8 out of 10 regions in Ghana. Greater Accra region recorded 73% of the cases (12,120 cases with 97 deaths (CFR 0.7%). We evaluated the cholera surveillance system to describe operation of the system, and assess its attributes to determine whether the system is meeting the objectives. Methods : this was a cross-sectional study. We used the CDC Updated Guidelines for Evaluating Public Health Surveillance System. We interviewed key stakeholders using a structured questionnaire to collect information about the system and its attributes. We reviewed cholera data from 2011- 2015 from the Health Information System at district and regional levels. The system attributes were assessed and scored for description and comparison on a Likert scale from 1 to 4. Data was analyzed using Epi-info and Microsoft Excel. Results : the Cholera surveillance system was included in the Integrated Disease Surveillance and Response with a clear case definition and laboratory support at all levels. The system was simple and flexible as it is able to adapt to changes. It was also acceptable by all and was stable, and highly sensitive due to the

Epidemiology and Antibiogram Profile of Vibrio cholerae Isolates between 2004-2013 from Odisha, India.

Cholera is an acute diarrheal disease caused by Vibrio cholerae serogroups O1 and O139, which are known to cause epidemics of cholera in Odisha. The present study was intended to document the antibiotic resistance pattern among clinical isolates of both serogroups of V. cholerae (O1 and O139) isolated during 2004-2013. Nine-hundred nine isolates of V. cholerae were included in this study and were identified by standard procedures. An antibiotic sensitivity test was performed by the disc diffusion method. The seasonality of cholera in this region indicated that there was one peak in the rainy season only. The number of cholera cases started increasing from July and declined starting from the month of October onward. The adult age group of patients was the worst affected among all age groups of patients. The 2 different serogroups of V. cholerae (O1 and O139) showed different prevalence rates (%) of resistance to all the antibiotics in each year. Serogroup O1 showed uniformly high resistance to co-trimoxazole, furazolidone, and nalidixic acid throughout the study. Chloramphenicol encountered resistance only during 2009, but the strains were sensitive in the other years. The emergence of multiple drug-resistant V. cholerae strains may significantly influence the control of future outbreaks and epidemics of cholera in this region.

Persistent diarrhoea in a 5-month-old baby carrying Vibrio cholerae nonO1/nonO139 producing Haitian cholera toxin.

Cholera toxin (CT) is the principal virulence factor of Vibrio cholerae for fatal cholera diarrhoea. Serogroups O1 and O139 harbour CT and are known to be epidemic strains. The remaining serogroups (nonO1/nonO139) are non-toxigenic and may be associated with mild disease. O1 serogroup emerged with a variant of CT known as Haitian cholera toxin (HCT). The HCT strains are hypervirulent and have been associated with severe cholera outbreaks in India, Western Africa and Haiti. Here, we report the presence of HCT (ctxB7) in a nonO1/nonO139 isolate causing persistent diarrhoea.

Flagellar motility, extracellular proteases and Vibrio cholerae detachment from abiotic and biotic surfaces

Vibrio cholerae of serogroups O1 and O139, the causative agent of Asiatic cholera, continues to be a major global health threat. This pathogen utilizes substratum-specific pili to attach to distinct surfaces in the aquatic environment and the human small intestine and detaches when conditions become unfavorable. Both attachment and detachment are critical to bacterial environmental survival, pathogenesis and disease transmission. However, the factors that promote detachment are less understood. In this study, we examine the role of flagellar motility and hemagglutinin/protease (HapA) in vibrio detachment from a non-degradable abiotic surface and from the suckling mouse intestine. Flagellar motility facilitated V. cholerae detachment from abiotic surfaces. HapA had no effect on the stability of biofilms formed on abiotic surfaces despite representing >50% of the proteolytic activity present in the extracellular matrix. We developed a balanced lethal plasmid system to increase the bacterial cyclic diguanylate (c-di-GMP) pool late in infection, a condition that represses motility and HapA expression. Increasing the c-di-GMP pool enhanced V. cholerae colonization of the suckling mouse intestine. The c-di-GMP effect was fully abolished in hapA isogenic mutants. These results suggest that motility facilitates detachment in a substratum-independent manner. Instead, HapA appears to function as a substratum-specific detachment factor.

Bacterial pathogens of pigs with particular reference to Escherichia coli: A systematic review and meta-analysis

Pigs are ungulate animals of the genus Suis and family Suidae. They are globally spread but restricted in certain countries due to religious and cultural beliefs. Pork serves as an important source of protein (38% of meat consumed in the world). While pig production remains a profitable enterprise, commercial and particularly the small-scale farmers face huge constraint in this husbandry practice, one of the most important being bacterial infections and its associated with morbidity and mortality. In this work, we reviewed the prevalence of bacterial infections in pigs with particular reference to Escherichia coli, a bacterium that is regularly isolated and can lead to multiple infections in pigs. Literatures were searched on selected veterinary and biological data bases in 2016 with focus on natural infections and isolates from natural infections with epidemiological details. Pathotypes, serotypes and serogroups of E. coli, the country of origin, source, growth stage, age of pigs infected, disease outbreak, the number of samples and type of samples, numbers and percentage of positive samples and isolates were used as filters. Pathotypes reported include enterotoxigenic E. coli (ETEC) 66.7%, enterotoxigenic E. coli and shiga toxigenic E. coli (ETEC and STEC) 14.3%, STEC only (7.9%), enterotoxigenic E. coli/enteropathogenic E. coli/enteroaggregative E. coli (ETEC/EPEC/EAE) 31.7%. Others were enterohaemorrhagic E. coli (EHEC), diffusely adherent E. coli (DAEC) (ETEC, EPEC, STEC) and extra-intestinal pathogenic E. coli (ExPEC). Twenty-nine countries with documented records of cases of E. coli were included with the USA reporting, the highest number followed by China. About 74% of the samples were taken from farms and others were from samples submitted to research laboratories and veterinary faculties for necropsy. Serogroups O141, O149, O139, O138, O8 and O9 were most common. Piglets were most affected (52.3%) followed by weaners (39.6%) and porkers (7.9%) with age ranging from 1 to 392 days old. A total of 24,854 isolates were considered, 10477 (42.2%) were positives and the following genes were carried: STa, STb, LT, stx1, stx2, Stx-2e, F4, F5, F6, F18, F41, AIDA, EAST1, eae, paa and hlyA. The diseases produced by E. coli were neonatal diarrhoea, colibacillosis, post-weaning diarrhoea and edema disease. The associated risk factors were poor housing, management and feed changes, extensive use of antibiotics as prophylaxis, overcrowding, and high humidity and temperature changes. India, USA, Japan, Slovakia, Denmark Sweden and Poland were countries with significant reports and high detection of virulence factors (72 to 100%). Key words: Escherichia coli, diarrhea, serogroups, enterotoxigenic, colibacillosis.

Re-classification within the serogroups O3 and O8 of Citrobacter strains

BackgroundCitrobacter strains are opportunistic pathogens often responsible for serious enteric as well as extra-intestinal diseases, and therefore the O-antigenic scheme, still in use in diagnostic identification, should be set for proper serotyping. The structures of more than 30 different Citrobacter O-antigens (O-polysaccharide chains of the lipopolysaccharides) of 43 Citrobacter O-serogroups have been elucidated so far. However, relationships between strains in several heterogeneous serogroups still need to be clarified by immunochemical studies. These include complex serogroups O3 and O8, represented by 20 and 7 strains, respectively, which are the subject of the present work. Earlier, the O-polysaccharide structures have been determined for Citrobacter O3 strain Be35/57 (PCM 1508) and Citrobacter O8 strain Be64/57 (PCM 1536).ResultsSerological studies (immunoblotting) carried out on Citrobacter lipopolysaccharides from different strains ascribed to serogroups O3 and O8 showed that each of these serogroups should be divided into non-cross-reacting subgroups. Based on the results of chemical analyses and 1H and 13C NMR spectroscopy the structure of Citrobacter O-antigens from strains PCM 1504 (O6) and PCM 1573 (O2) have been established. Chemical data combined with serological analyses showed that several Citrobacter strains should be reclassified into other serogroups.ConclusionsImmunochemical studies carried out on Citrobacter LPS, described in this paper, showed the expediency of reclassification of: 1) strains PCM 1504 and PCM 1573 from serogroups O6 and O2 to serogroups O3 and O8, respectively, 2) strains PCM 1503 and PCM 1505 from serogroups O3 and O8 to new serogroups O3a and O8a, respectively.

A Rare Case of Non-O1, Non-O139 Vibrio Cholera Bacteraemia Causing Hepatic Encephalopathy in Cirrhotic Patient

Background: Vibrio cholera serogroups O1 or O139 are the aetiological agents of cholera. The pathogenicity of non-O1, non-O139 Vibrio cholera (NOVC) is less well known. NOVC bacteria are responsible for gastrointestinal infections or, more rarely, bacteraemia in patients with an underlying disease, leading to life-threatening complications. Case Summary: We report a case of 63 years old male who has chronic liver disease with portal hypertension and presented to us with grade III hepatic encephalopathy. He was started on rifaximin, lactulose solution and intravenous cephalosporin after sending his blood cultures. Later his blood culture grew non-O1, non-O139 Vibrio cholera strain. He was continued on cephalosporin as per sensitivity pattern and early antibiotic therapy allowed good outcome in our case. On retrospective history, contaminated water was the source of infection. Non-O1, non-O139 Vibrio cholera bacteraemia is rare but potentially fatal infection and cirrhotic patients are at particular risk. Conclusion: The aim of this case report is to underline the virulence of non-choleragenic Vibrio strains, possibly linked to haemolysin production, and the potential danger of consuming contaminated water, undercooked seafood or exposing wounds to sea water in cirrhotic patients. The authors have none to declare.

PROBLEM OF ESCHERICHIA COLI INFECTION IN BROILERS IN QENA PROVINCE

The present study was conducted on 81 commercial broiler chicken farms aged (1-45 days) located in five different centers at Qena province (Qena, Qift, Deshna, Qus and Nag-Hammadi), For bacteriological examination, Samples were taken from diseased and freshly dead chickens (liver; lung; intestine; trachea; nasal cavity; kidneys; yolk sacs; pericardium; and air sacs). The results revealed that 50 out of 600 samples (8.3%) were positive for E. coli isolation, where 30 isolates (9.0%) from 332 baby chicks (up to one week), 20 isolates (7.4%) from 268 broilers (from one week to 6 weeks) were positive for E. coli isolation. Thirty-seven seogroups of E. coli were obtained by serological identification (O1, O6, O8, O20, O26, O27, O44, O86a, O115, O125, O128, O136, O146, O152, O158, O159, O164, O166, O167,O168 and O169) represented as 4 strains were serotyped O27 (8%), 3 strains O44 (6%), 3 strains O125 (6%), 3 strains O152 (6%), 3 strains O159 (6%), 2 strains O1 (4%), 2 strains O6 (4%), 2 strains O20 (4%), 2 strains O26 (4%), 2 strains O166 (4%), 1 strain for each of O8, O86a, O115, O128, O136 ,O146, O158, O164, O167, O168, O169 with (2%) for each of them and 13 isolates were untyped (26%) by the available antisera. Multiplex PCR showed that ompA virulence gene was detected in all serogroups except O8. Moreover, papC virulence gene was detected in all serogroups except O8, O86a, O136, O146, O167 and O169. While Stx2 virulence gene was detected only in serotypes O27 & O125. The eaeA gene was amplified in serogroups O1, O20, O26, O115, O152, O166, O168 and O169. Finally, tsh virulence gene was detected in all serogroups except O20, O26, O86a, O115, O128, O167 and O169.

Detection of enteropathogenic Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus: performance of real-time PCR kits in an interlaboratory study

Bacteria belonging to the genus Vibrio are very common to marine and estuarine environments and are found in association with marine plants and animals. Vibrio parahaemolyticus strains that produce thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH), toxigenic strains of Vibrio cholerae belonging to the serogroups O1 and O139, and Vibrio vulnificus are regarded as important food-borne pathogens, which represent a serious and growing public health hazard. In this study, we established and validated real-time PCR assays for the detection of enteropathogenic Vibrio strains. In a first step, seafood is investigated for the presence of the three Vibrio species. In case of detection of V. cholerae or V. parahaemolyticus, samples are tested for the presence of the cholera toxin gene (ctxA) or tdh/trh genes, respectively, in a second step. All PCR analyses were performed with the same cycling program. Primer/probe sets were thoroughly tested for limit of detection, inclusivity, exclusivity and performance in the matrix. In an interlaboratory study, kits based on these primer/probe sets were successfully tested with cultural and DNA samples.

Characterization of Virulence Potential of Pseudomonas Aeruginosa Isolated from Bovine Meat, Fresh Fish, and Smoked Fish.

Pseudomonas aeruginosa owns a variability of virulence factors. These factors can increase bacterial pathogenicity and infection severity. Despite the importance of knowledge about them, these factors are not more characterized at level of strains derived from local food products. This study aimed to characterize the virulence potential of P. aeruginosa isolated from various animal products. Several structural and virulence genes of P. aeruginosa including lasB, exoS, algD, plcH, pilB, exoU, and nan1 were detected by polymerase chain reaction (PCR) on 204 strains of P. aeruginosa. They were isolated from bovine meat (122), fresh fish (49), and smoked fish (33). The 16S rRNA gene was detected on 91.1% of the presumptive strains as Pseudomonas. The rpoB gene showed that 99.5% of the strains were P. aeruginosa. The lasB gene (89.2%) was the most frequently detected (p < 0.05). In decreasing importance order, exoS (86.8%), algD (72.1%), plcH (72.1%), pilB (40.2%), and exoU (2.5%) were detected. The lasB gene was detected in all strains of P. aeruginosa serogroups O11 and O16. The prevalence of algD, exoS, and exoU genes in these strains varied from 51.2% to 87.4%. The simultaneous determination of serogroups and virulence factors is of interest for the efficacy of surveillance of infections associated with P. aeruginosa.

The Escherichia coli Serogroup O1 and O2 Lipopolysaccharides Are Encoded by Multiple O-antigen Gene Clusters.

Escherichia coli strains belonging to serogroups O1 and O2 are frequently associated with human infections, especially extra-intestinal infections such as bloodstream infections or urinary tract infections. These strains can be associated with a large array of flagellar antigens. Because of their frequency and clinical importance, a reliable detection of E. coli O1 and O2 strains and also the frequently associated K1 capsule is important for diagnosis and source attribution of E. coli infections in humans and animals. By sequencing the O-antigen clusters of various O1 and O2 strains we showed that the serogroups O1 and O2 are encoded by different sets of O-antigen encoding genes and identified potentially new O-groups. We developed qPCR-assays to detect the various O1 and O2 variants and the K1-encoding gene. These qPCR assays proved to be 100% sensitive and 100% specific and could be valuable tools for the investigations of zoonotic and food-borne infection of humans with O1 and O2 extra-intestinal (ExPEC) or Shiga toxin-producing E. coli (STEC) strains.

Characterization and Genetic Variation of Vibrio cholerae Isolated from Clinical and Environmental Sources in Thailand.

Cholera is still an important public health problem in several countries, including Thailand. In this study, a collection of clinical and environmental V. cholerae serogroup O1, O139, and non-O1/non-O139 strains originating from Thailand (1983 to 2013) was characterized to determine phenotypic and genotypic traits and to investigate the genetic relatedness. Using a combination of conventional methods and whole genome sequencing (WGS), 78 V. cholerae strains were identified. WGS was used to determine the serogroup, biotype, virulence, mobile genetic elements, and antimicrobial resistance genes using online bioinformatics tools. In addition, phenotypic antimicrobial resistance was determined by the minimal inhibitory concentration (MIC) test. The 78 V. cholerae strains belonged to the following serogroups O1: (n = 44), O139 (n = 16) and non-O1/non-O139 (n = 18). Interestingly, we found that the typical El Tor O1 strains were the major cause of clinical cholera during 1983–2000 with two Classical O1 strains detected in 2000. In 2004–2010, the El Tor variant strains revealed genotypes of the Classical biotype possessing either only ctxB or both ctxB and rstR while they harbored tcpA of the El Tor biotype. Thirty O1 and eleven O139 clinical strains carried CTXϕ (Cholera toxin) and tcpA as well four different pathogenic islands (PAIs). Beside non-O1/non-O139, the O1 environmental strains also presented chxA and Type Three Secretion System (TTSS). The in silico MultiLocus Sequence Typing (MLST) discriminated the O1 and O139 clinical strains from other serogroups and environmental strains. ST69 was dominant in the clinical strains belonging to the 7th pandemic clone. Non-O1/non-O139 and environmental strains showed various novel STs indicating genetic variation. Multidrug-resistant (MDR) strains were observed and conferred resistance to ampicillin, azithromycin, nalidixic acid, sulfamethoxazole, tetracycline, and trimethoprim and harboured variants of the SXT elements.For the first time since 1986, the presence of V. cholerae O1 Classical was reported causing cholera outbreaks in Thailand. In addition, we found that V. cholerae O1 El Tor variant and O139 were pre-dominating the pathogenic strains in Thailand. Using WGS and bioinformatic tools to analyze both historical and contemporary V. cholerae circulating in Thailand provided a more detailed understanding of the V. cholerae epidemiology, which ultimately could be applied for control measures and management of cholera in Thailand.

Prevalence and Antibiotic Resistance of Pseudomonas aeruginosa Isolated from Bovine Meat, Fresh Fish and Smoked Fish.

Background and Objectives: Pseudomonas aeruginosa is a major opportunistic pathogen with several resistance factors that are partially evaluated in local products. This study aimed to evaluate P. aeruginosa multidrug-resistant (PAMDR) contaminating animal products. Materials and Methods: API20NE methods, susceptibility testing, serotyping, and molecular characterizations by using rpoB gene were performed. Results: On a set of 500 samples analyzed, API 20NE identified 205 (91.1%) of the 225 presumptive isolates as Pseudomonas aeruginosa. The rpoB gene confirmed that 204 (99.5%) of the 205 strains were Pseudomonas aeruginosa. The strains of P. aeruginosa were isolated from bovine meat (122), fresh fish (49) and smoked fish (33). With a total prevalence of 36.2%, 181 strains of Pseudomonas aeruginosa out of 204 isolated were multidrug-resistant. The prevalence of Pseudomonas aeruginosa multidrug-resistant was 47.8%, 33.1% and 20.0%, respectively, in bovine meat, fresh fish and smoked fish. The percentage of resistance showed by P. aeruginosa strains were 98.4% for aztreonam, 51.4% ticarcillin + clavulanic acid, 50.4% ticarcillin, 31.4% piperacillin, 33.6% ciprofloxacin, 17.0% cefepime, 6.9% ceftazidim 7.2% imipenem, 4.5% colistin and 0.0% fosfomycin. Pseudomonas aeruginosa strains mainly resistant to ticarcillin, ticarcillin-clavulanic acid, cefepime, imipenem, ceftazidim, ciprofloxacin and piperacillin were serogroups O5, O7 and O11. Conclusion: These animal products play an active role in the spread of antibiotic resistance.

Comparative genomics of European avian pathogenic E. Coli (APEC)

BackgroundAvian pathogenic Escherichia coli (APEC) causes colibacillosis, which results in significant economic losses to the poultry industry worldwide. However, the diversity between isolates remains poorly understood. Here, a total of 272 APEC isolates collected from the United Kingdom (UK), Italy and Germany were characterised using multiplex polymerase chain reactions (PCRs) targeting 22 equally weighted factors covering virulence genes, R-type and phylogroup. Following these analysis, 95 of the selected strains were further analysed using Whole Genome Sequencing (WGS).ResultsThe most prevalent phylogroups were B2 (47%) and A1 (22%), although there were national differences with Germany presenting group B2 (35.3%), Italy presenting group A1 (53.3%) and UK presenting group B2 (56.1%) as the most prevalent. R-type R1 was the most frequent type (55%) among APEC, but multiple R-types were also frequent (26.8%). Following compilation of all the PCR data which covered a total of 15 virulence genes, it was possible to build a similarity tree using each PCR result unweighted to produce 9 distinct groups. The average number of virulence genes was 6–8 per isolate, but no positive association was found between phylogroup and number or type of virulence genes. A total of 95 isolates representing each of these 9 groupings were genome sequenced and analysed for in silico serotype, Multilocus Sequence Typing (MLST), and antimicrobial resistance (AMR). The UK isolates showed the greatest variability in terms of serotype and MLST compared with German and Italian isolates, whereas the lowest prevalence of AMR was found for German isolates. Similarity trees were compiled using sequencing data and notably single nucleotide polymorphism data generated ten distinct geno-groups. The frequency of geno-groups across Europe comprised 26.3% belonging to Group 8 representing serogroups O2, O4, O18 and MLST types ST95, ST140, ST141, ST428, ST1618 and others, 18.9% belonging to Group 1 (serogroups O78 and MLST types ST23, ST2230), 15.8% belonging to Group 10 (serogroups O8, O45, O91, O125ab and variable MLST types), 14.7% belonging to Group 7 (serogroups O4, O24, O35, O53, O161 and MLST type ST117) and 13.7% belonging to Group 9 (serogroups O1, O16, O181 and others and MLST types ST10, ST48 and others). The other groups (2, 3, 4, 5 and 6) each contained relatively few strains.However, for some of the genogroups (e.g. groups 6 and 7) partial overlap with SNPs grouping and PCR grouping (matching PCR groups 8 (13 isolates on 22) and 1 (14 isolates on 16) were observable). However, it was not possible to obtain a clear correlation between genogroups and unweighted PCR groupings. This may be due to the genome plasticity of E. coli that enables strains to carry the same virulence factors even if the overall genotype is substantially different.ConclusionsThe conclusion to be drawn from the lack of correlations is that firstly, APEC are very diverse and secondly, it is not possible to rely on any one or more basic molecular or phenotypic tests to define APEC with clarity, reaffirming the need for whole genome analysis approaches which we describe here.This study highlights the presence of previously unreported serotypes and MLSTs for APEC in Europe. Moreover, it is a first step on a cautious reconsideration of the merits of classical identification criteria such as R typing, phylogrouping and serotyping.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3289-7) contains supplementary material, which is available to authorized users.

Efficacy of an experimental E. coli inactivated vaccine in turkey poults

E. coli infections are responsible for great economic losses in the poultry industry worldwide, bringing serious threat to the turkey industry. The present investigation aimed to prepare a potent vaccine from E. coli serogroups O1 and O78 to aid in control of colibacillosis in turkey. One hundred commercial 14 days-old turkey poults were used and divided into three groups; first group was vaccinated twice with 3 weeks interval by prepared inactivated E.coli vaccine adjuvanted with aluminum hydroxide gel, second group was vaccinated twice with 3 weeks interval by prepared inactivated E.coli vaccine adjuvanted with montanide ISA70, third group was left as unvaccinated control one. The immune response was measured by MAT (Microagglutination test), ELISAand challenge test. It was found that the protection rate for inactivated vaccine with aluminum hydroxide gel and E.coli inactivated vaccine with montanide ISA70 were 80% and 85% respectively although it was 30% among the unvaccinated group.