Characterization of enterovirulent Escherichia coli isolated from yak calves died of diarrhoea in India

Author(s):  
Samiran Bandyopadhyay ◽  
Achintya Mahanti ◽  
Indranil Samanta ◽  
Subhasis Batabyal

Shiga toxin producing (STEC), enteropathogenic (EPEC) and enterotoxigenic Escherichia coli (ETEC) were isolated from 29 diarrhoeic yak calves from two districts of Arunachal Pradesh, India (West Kameng and Tawang) during 2005 to 2011. The STEC (28) and EPEC (12) isolates belonged to 25 different O serogroups. Among the 28 STEC isolates, 8 (28.5%) isolates carried only stx1, 10 (35.7%) isolates were positive for both stx1 and stx2, 10 (35.7%) isolates carried only stx2. The stx variants such as stx1c, stx2c, stx2d and stx2e were detected in 7 (25%), 9 (32.1%), 1 (3.5%) and 4 (14.28%) isolates, respectively. Among the 12 EPEC isolates, 2 (4.65%) strains were ‘typical’ possessing bfpA gene. The ehxA and saa genes were present in 19 and 4 isolates, respectively. Among the 14 ETEC isolates, 6 (42.8%), 7 (50%), 5 (35.7%), 5 (35.7%), 7 (50%) and 6 (42.8%) isolates carried genes coding for STa, STb, LT, F5, F41 and EAST1, respectively. The present study detected LT, STb, F41 as the most prevalent type in yaks associated with diarrhoea. Further, the STEC, EPEC and ETEC isolates showed resistance against furazolidone (40%), nitrofurantoin (39%), nalidixic acid (38%), erythromycin (38%), kanamycin (38%), amikacin (37%). The dendrogram revealed clonal relationship among the isolates after RAPD/ERIC analysis. The study could not detect any specific RAPD/ERIC cluster associated with origin, serotypes or virotypes of the isolates. Thus, it was concluded that genetically diverse, multi-drug resistant enterovirulent E. coli were associated with death due to diarrhoea in yak calves in India.

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Amit Gaurav ◽  
Varsha Gupta ◽  
Sandeep K. Shrivastava ◽  
Ranjana Pathania

AbstractThe increasing prevalence of antimicrobial resistance has become a global health problem. Acinetobacter baumannii is an important nosocomial pathogen due to its capacity to persist in the hospital environment. It has a high mortality rate and few treatment options. Antibiotic combinations can help to fight multi-drug resistant (MDR) bacterial infections, but they are rarely used in the clinics and mostly unexplored. The interaction between bacteriostatic and bactericidal antibiotics are mostly reported as antagonism based on the results obtained in the susceptible model laboratory strain Escherichia coli. However, in the present study, we report a synergistic interaction between nalidixic acid and tetracycline against clinical multi-drug resistant A. baumannii and E. coli. Here we provide mechanistic insight into this dichotomy. The synergistic combination was studied by checkerboard assay and time-kill curve analysis. We also elucidate the mechanism behind this synergy using several techniques such as fluorescence spectroscopy, flow cytometry, fluorescence microscopy, morphometric analysis, and real-time polymerase chain reaction. Nalidixic acid and tetracycline combination displayed synergy against most of the MDR clinical isolates of A. baumannii and E. coli but not against susceptible isolates. Finally, we demonstrate that this combination is also effective in vivo in an A. baumannii/Caenorhabditis elegans infection model (p < 0.001)


2021 ◽  
Vol 10 (1) ◽  
pp. 51-54

Sorbitol non-fermenting Shiga toxin producing Escherichia coli (SNF-STEC) is considered as a significant emerging pathogen. Though, cattle and buffaloes are the chief reservoir, species like goat, sheep, deer and other ruminants can also harbor this pathogen. Therefore, this pathogen can easily be transmitted to human and other animals through food chain and their environment. The present study, aimed to ascertain the antibiotic resistance profile of SNF-STEC isolates from buffaloes as well as to detect the resistance genes. A total of 33 sorbitol non-fermenting (SNF) E. coli isolates were tested against ten commonly used antibiotics both in human and veterinary medicine. Results revealed that 78.8% isolates were resistant to sulfamethoxazole-trimethoprim and nalidixic acid whereas 60.6% to tetracycline and 48.5% to doxycycline. The majority of the isolates were found sensitive to both gentamycin and ciprofloxacin (90%) followed by erythromycin (66.7%) and ceftriaxone (51.5%). Of 33 SNF E. coli, 12 were STEC harboring both stx1 and stx2 gene that dictated 66.7% isolates were found resistant to sulfamethoxazole-trimethoprim and nalidixic acid followed by ampicillin (58.3%) and tetracycline (58.3%). blaTEM was detected in 66.7% ampicillin resistant isolates and sul2 was exposed in 34.6% sulfamethoxazole-trimethoprim resistant isolates. sul1 gene was negative for the sulfamethoxazole-trimethoprim resistant isolates.


Infectio ◽  
2017 ◽  
Vol 21 (2) ◽  
Author(s):  
Eman Fathi Sharafa ◽  
Iman I. Shabanaa

Shiga toxin-producing Escherichia coli (STEC) strains have emerged as important foodborne pathogens of global public health concern, causing life-threatening diseases. Sheep and their products have been documented as important reservoirs for STECs, especially E. coli O157. The aim of this study was to investigate STECs from diarrheal human and sheep in Al-Madinah Al-Munawarah, Saudi Arabia. Fecal samples were collected between June and August, 2015 from diarrheal humans (n = 134) and sheep (n = 87). Presumptive E. coli human-and sheep-isolated strains were identified for their serotypes, the associated virulence genes (Shiga toxin [stx1 , stx2 ], haemolysin [ehxA] and intimin [eae]) by polymerase chain reaction and their susceptibility to antibiotics. Pulsed-field gel electrophoresis (PFGE) was used to demonstrate the genetic relatedness between Serotype O157:H7 human- and sheep-isolated strains. Forty eight (48/221; 21.7%) STECs were recovered from both human and sheep, their serotypes were as follows: O157:H7, O26:H11, O157:HNM, O26:HNM, O128:H2, O48:HNM, O111:HNM and OUT:HUT. Various virulence profiles and multiple antibiotic resistance were observed among the isolates. Twenty eight O157:H7 serotypes (17 human isolates and 11 sheep isolates) were identified in 13 PFGE pulsotypes, where human and sheep isolates were highly related. PFGE banding profiles together with serotypes and genotypes afford proof that human and sheep can be colonized and infected with similar E. coli O157:H7 strains. Our findings highlight the importance of epidemiological and microbiological surveillance of STECs; as well as the development of control measures to decrease risks associated with zoonotic O157:H7.


2020 ◽  
Author(s):  
Meghan Maguire ◽  
Julie A. Kase ◽  
Dwayne Roberson ◽  
Tim Muruvanda ◽  
Eric W. Brown ◽  
...  

ABSTRACTShiga toxin-producing Escherichia coli (STEC) contamination of agricultural water might be an important factor to recent foodborne illness and outbreaks involving leafy greens. Whole genome sequencing generation of closed bacterial genomes plays an important role in source tracking. We aimed to determine the limits of detection and classification of STECs by qPCR and nanopore sequencing using enriched irrigation water artificially contaminated with E. coli O157:H7 (EDL933). We determined the limit of STEC detection by qPCR to be 30 CFU/reaction, which is equivalent to 105 CFU/ml in the enrichment. By using Oxford Nanopore’s EPI2ME WIMP workflow and de novo assembly with Flye followed by taxon classification with a k-mer analysis software (Kraken), E. coli O157:H7 could be detected at 103 CFU/ml (68 reads) and a complete fragmented E. coli O157:H7 metagenome-assembled genome (MAG) was obtained at 105-108 CFU/ml. Using a custom script to extract the E. coli reads, a completely closed MAG was obtained at 107-108 CFU/ml and a complete, fragmented MAG was obtained at 105-106 CFU/ml. In silico virulence detection for E. coli MAGs for 105-108 CFU/ml showed that the virulotype was indistinguishable from the spiked E. coli O157:H7 strain. We further identified the bacterial species in the un-spiked enrichment, including antimicrobial resistance genes, which could have important implications to food safety. We propose this workflow could be used for detection and complete genomic characterization of STEC from a complex microbial sample and could be applied to determine the limit of detection and assembly of other foodborne bacterial pathogens.IMPORTANCEFoodborne illness caused by Shiga toxin-producing E. coli (STEC) ranges in severity from diarrhea to hemolytic uremic syndrome and produce-related incidence is increasing. The pervasive nature of E. coli requires not only detection, but also a complete genome to determine potential pathogenicity based on stx and eae genes, serotype, and other virulence factors. We have developed a pipeline to determine the limits of nanopore sequencing for STECs in a metagenomic sample. By utilizing the current qPCR in the FDA Bacteriological Analytical Manual (BAM) Chapter 4A, we can quantify the amount of STEC in the enrichment and then sequence and classify the STEC in less than half the time as current protocols that require a single isolate. These methods have wide implications for food safety, including decreased time to STEC identification during outbreaks, characterization of the microbial community, and the potential to use these methods to determine the limits for other foodborne pathogens.


1970 ◽  
Vol 8 (1) ◽  
pp. 23-26 ◽  
Author(s):  
SK Paul ◽  
MSR Khan ◽  
MA Rashid ◽  
J Hassan ◽  
SMS Mahmud

The research works was conducted with a view to isolate and identify the Escherichia coli (E. coli) organism from diarrhoeic cases of buffalo reared in selected areas of Bangladesh as well the prevalence and antibiotic sensitivity pattern of the isolated E. coli in the Department of Microbiology and Hygiene, Bangladesh Agricultural University (BAU), Mymensingh-2202 during the period from April 2008 to May 2009. A total of 50 rectal swab samples were collected from 4 different places namely Haluaghat and Boira of Mymensingh, Madupur of Tangail and Kazipur of Sirajgonj districts. The samples were aseptically carried to the laboratory of the Department of Microbiology and Hygiene and subjected to different cultural, morphological and biochemical examinations. Upon cultural, morphological and biochemical examinations 23 (45%) samples were found to be positive for E. coli. The highest prevalence was found in Haluaghat, Mymensingh (53.33%) and the lowest (40.00%) in Boira, Mymensingh and Kazipur, Sirajganj. Antibiogram study revealed that the isolated E. coli was highly sensitive to Enrofloxacin and Ciprofloxacin, moderately sensitive to Cefalexin and Amoxicillin, and resistant to Nalidixic acid and Erythromycin. DOI = 10.3329/bjvm.v8i1.7398 Bangl. J. Vet. Med. (2010). 8(1): 23-26


1970 ◽  
Vol 20 (1) ◽  
pp. 23-30
Author(s):  
Augustin Kakon Gomes ◽  
Humaira Akhter ◽  
Belal Mahmud ◽  
Sirajul Islam Khan ◽  
Anowara Begum

Isolation, identification and characterization of Escherichia coli were carried out in terms of biochemical, serological, antibiogram, plasmid profile and culture condition of urine samples. Out of 50 urine samples, 36 were positive for E. coli that were confirmed by biochemical (e.g. oxidase, kligler’s iron agar, indole, methyl red-voges proskauer and citrate utilization) tests and 4-methyl-umbelliferyl-β-D-glucoronide (MUG) test. Twenty seven strains gave positive result with different antisera whereas nine strains were untypable (UT), respectively. Thirty six strains were also tested by antibiogram against ten different antibiotics. Most E. coli strains were resistant to bacitracin, ampicillin, novobiocin, kanamycin and streptomycin. Eighty three per cent strains were sensitive to ciprofloxacin and gentamycin while 11 and 12% showed resistance to ciprofloxacin and gentamycin, respectively. By plasmid profile analysis of the 36 strains seven different plasmid patterns were observed. Comparison of the plasmid profiles with the antibiogram results indicated the presence of resistant (R) plasmid. Thirty four isolates of E. coli contained a common 25 kb plasmid that may possibly be responsible for drug resistance in this study. The results suggested that the prevalence of multi-drug resistant and new serotype of E. coli may be increasing rapidly which is alarming for treatment of urinary tract infection in Bangladesh.Key words: Prevalence; Characterization; E. coli; Multi-drug resistant; Serotype; Clinical sampleDOI: http://dx.doi.org/10.3329/dujbs.v20i1.8834Dhaka Univ. J. Biol. Sci. 20(1): 23-30, 2011 (January)


2006 ◽  
Vol 72 (3) ◽  
pp. 2254-2259 ◽  
Author(s):  
Lutz Geue ◽  
Thomas Selhorst ◽  
Christina Schnick ◽  
Birgit Mintel ◽  
Franz J. Conraths

ABSTRACT Variations in time and space of a clonal group of Escherichia coli O165:H25 on a cattle farm were monitored. The virulence marker pattern (stx genes, eae gene, hly EHEC gene, katP gene, espP gene, efa gene) suggests that E. coli O165:H25 of bovine origin may represent a risk for human infection.


2020 ◽  
Vol 83 (11) ◽  
pp. 1909-1917
Author(s):  
SAIDA ESSENDOUBI ◽  
XIANQIN YANG ◽  
ROBIN KING ◽  
JULIA KEENLISIDE ◽  
JAVIER BAHAMON ◽  
...  

ABSTRACT The objective of this study was to determine the prevalence of Shiga toxin–producing Escherichia coli (STEC) O157:H7 in colon contents and on carcasses from pigs slaughtered at provincially licensed abattoirs (PLAs) in Alberta, Canada. In 2017, carcass sponge samples and colon content samples were collected from 504 healthy market hogs at 39 PLAs and analyzed for E. coli O157:H7. Carcass samples were also analyzed for E. coli and aerobic colony count (ACC). Nine (1.8%) of 504 carcass samples were confirmed positive for E. coli O157:H7. Seven (1.4%) of 504 colon content samples were confirmed positive for E. coli O157:H7. These positives were found in 5 (12.8%) of 39 PLAs from hogs originating from eight farms. The E. coli O157:H7 isolates recovered from the positive samples (n = 1 isolate per sample) were clonal, as determined by pulsed-field gel electrophoresis. Six E. coli O157:H7 isolates obtained over 8 months from one PLA that only processed hogs and sourced hogs from one farm had indistinguishable pulsed-field gel electrophoresis patterns. All 16 E. coli O157:H7 isolates harbored eae and ehxA and were of stx2a subtype, suggesting that swine can carry E. coli O157:H7 of importance to human health. All carcass sponge swabs (100%) were positive for ACC. E. coli was present in 72% of carcass swabs. Carcasses from PLAs slaughtering both beef and hogs had a numerically higher ACC mean value but not statistically different compared with the carcasses from PLAs slaughtering only swine (2,799 and 610 CFU/cm2, respectively). E. coli showed a similar trend with a mean value of 0.88 CFU/cm2 in PLAs slaughtering both species and 0.26 CFU/cm2 in PLAs slaughtering only swine (P ≤ 0.05). This study provides evidence that healthy market hogs from different producers and farms in Alberta can carry E. coli O157:H7, and some strains of the organism may be able to establish persistence on some swine farms. HIGHLIGHTS


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