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

Kumar, Pramod; Karmakar, Somenath; Prasad, Rajendra; Chopra, R. N.; Khandelwal, Sachin; Gupta, Sunil; Dhariwal, A C; Yadav, P. S.; Yadava, Pramod Kumar

doi:10.1016/j.nmni.2017.10.008

Cited by 6 publications

(4 citation statements)

References 14 publications

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“…The emergence of such virulent NAG vibrios is a threat to humankind. Actually, a new type of NAG vibrio with ctx has been isolated from a patient with persistent diarrhea ( Kumar et al, 2018 ). The strain possessed Haitian type CT, which is a type of CT, generated recently from the transfer of the mobile element encoding ctx .…”

Section: Discussionmentioning

confidence: 99%

Virulence of Cholera Toxin Gene-Positive Vibrio cholerae Non-O1/non-O139 Strains Isolated From Environmental Water in Kolkata, India

et al. 2021

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Cholera toxin (CT)-producing Vibrio cholerae O1 and O139 cause acute diarrheal disease and are proven etiological agents of cholera epidemics and pandemics. On the other hand, V. cholerae non-O1/non-O139 are designated as non-agglutinable (NAG) vibrios and are not associated with epidemic cholera. The majority of NAG vibrios do not possess the gene for CT (ctx). In this study, we isolated three NAG strains (strains No. 1, 2, and 3) with ctx from pond water in Kolkata, India, and examined their pathogenic properties. The enterotoxicity of the three NAG strains in vivo was examined using the rabbit ileal intestinal loop test. Strain No. 1 induced the accumulation of fluid in the loop, and the volume of fluid was reduced by simultaneous administration of anti-CT antiserum into the loop. The volume of fluid in the loop caused by strains No. 2 and 3 was small and undetectable, respectively. Then, we cultured these three strains in liquid medium in vitro at two temperatures, 25°C and 37°C, and examined the amount of CT accumulated in the culture supernatant. CT was accumulated in the culture supernatant of strain No.1 when the strain was cultured at 25°C, but that was low when cultured at 37°C. The CT amount accumulated in the culture supernatants of the No. 2 and No. 3 strains was extremely low at both temperature under culture conditions examined. In order to clarify the virulence properties of these strains, genome sequences of the three strains were analyzed. The analysis showed that there was no noticeable difference among three isolates both in the genes for virulence factors and regulatory genes of ctx. However, vibrio seventh pandemic island-II (VSP-II) was retained in strain No. 1, but not in strains No. 2 or 3. Furthermore, it was revealed that the genotype of the B subunit of CT in strain No. 1 was type 1 and those of strains No. 2 and 3 were type 8. Histopathological examination showed the disappearance of villi in intestinal tissue exposed to strain No. 1. In addition, fluid accumulated in the loop due to the action of strain No. 1 had hemolytic activity. This indicated that strain No. 1 may possesses virulence factors to induce severe syndrome when the strain infects humans, and that some strains of NAG vibrio inhabiting pond water in Kolkata have already acquired virulence, which can cause illness in humans. There is a possibility that these virulent NAG vibrios, which have acquired genes encoding factors involved in virulence of V. cholerae O1, may emerge in various parts of the world and cause epidemics in the future.

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Section: Discussionmentioning

confidence: 99%

Virulence of Cholera Toxin Gene-Positive Vibrio cholerae Non-O1/non-O139 Strains Isolated From Environmental Water in Kolkata, India

et al. 2021

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“…However, in recent years several studies reported NOVC strains with toxigenic genes and additional mobile genetic elements that confer resistance to multiple antibiotics ( 16 – 19 ). In addition in NOVC strains, accessory virulence factors such as a transcriptional activator for toxin-related genes including ctxAB ( toxR ), mannose-sensitive hemagglutinin pilus ( mshA ), different hemolysins ( hlyA ), repeats in toxin (RTX) toxin clusters, outer membrane proteins ( ompU ), cholix toxin ( chxA ), heat-stable enterotoxin ( stn ), flagellum-associated cytotoxin ( makA ), and glucose metabolism ( als ), may contribute directly or in a synergistic way to the infection process leading to diarrheal illness ( 20 – 24 ).…”

Section: Introductionmentioning

confidence: 99%

“…Clinical NOVC strains that contain genes pathogenic to humans despite not being O1/O139 V. cholerae strains are of public health concern. Recently, NOVC clinical V. cholerae strains exhibited genotypic profiles similar to the O1 El Tor Haiti (CT) variant in a 5-month-old baby in India ( 19 ). Furthermore, several NOVC clinical and environmental isolates carrying mobile genetic elements and thereby acquiring resistance to multiple antibiotics are of global concern because, in general, SXT genetic elements play a role in the evolution of the isolate ( 19 , 30 , 31 ).…”

Section: Introductionmentioning

confidence: 99%

Clinical and Environmental Vibrio cholerae Non-O1, Non-O139 Strains from Australia Have Similar Virulence and Antimicrobial Resistance Gene Profiles

et al. 2023

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“…We hypothesize that these non-toxigenic V. cholerae O1 strains may convert to toxigenic strain via chitin-induced natural transformation (Mahmud et al, 2014; Zhang et al, 2014; Chowdhury et al, 2015; Azarian et al, 2016). Interestingly, recent reports demonstrated that toxigenic V. cholerae non-O1/non-O139 strains, including strains carrying “Haitian” ctxAB genes, isolated from clinical and environmental settings caused severe diarrheal disease in India (Bhuyan et al, 2016; Kumar et al, 2018). Emergence of such toxigenic non-O1/non-O139 strains in India may well have resulted via chitin-induced natural transformation using exogenous gDNA from toxigenic V. cholerae strains circulating in that country.…”

Section: Discussionmentioning

confidence: 99%

Conversion of a recA-Mediated Non-toxigenic Vibrio cholerae O1 Strain to a Toxigenic Strain Using Chitin-Induced Transformation

et al. 2019

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Toxigenic Vibrio cholerae strains, including strains in serogroups O1 and O139 associated with the clinical disease cholera, are ubiquitous in aquatic reservoirs, including fresh, estuarine, and marine environments. Humans acquire cholera by consuming water and/or food contaminated with the microorganism. The genome of toxigenic V. cholerae harbors a cholera-toxin producing prophage (CT-prophage) encoding genes that promote expression of cholera toxin. The CT-prophage in V. cholerae is flanked by two satellite prophages, RS1 and TLC. Using cell surface appendages (TCP and/or MSHA pili), V. cholerae can sequentially acquire TLC, RS1, and CTX phages by transduction; the genome of each of these phages ultimately integrates into V. cholerae’s genome in a site-specific manner. Here, we showed that a non-toxigenic V. cholerae O1 biotype El Tor strain, lacking the entire RS1-CTX-TLC prophage complex (designated as RCT: R for RS1, C for CTX and T for TLC prophage, respectively), was able to acquire RCT from donor genomic DNA (gDNA) of a wild-type V. cholerae strain (E7946) via chitin-induced transformation. Moreover, we demonstrated that a chitin-induced transformant (designated as AAS111) harboring RCT was capable of producing cholera toxin. We also showed that recA, rather than xerC and xerD recombinases, promoted the acquisition of RCT from donor gDNA by the recipient non-toxigenic V. cholerae strain. Our data document the existence of an alternative pathway by which a non-toxigenic V. cholerae O1 strain can transform to a toxigenic strain by using chitin induction. As chitin is an abundant natural carbon source in aquatic reservoirs where V. cholerae is present, chitin-induced transformation may be an important driver in the emergence of new toxigenic V. cholerae strains.

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

Cited by 6 publications

References 14 publications

Virulence of Cholera Toxin Gene-Positive Vibrio cholerae Non-O1/non-O139 Strains Isolated From Environmental Water in Kolkata, India

Virulence of Cholera Toxin Gene-Positive Vibrio cholerae Non-O1/non-O139 Strains Isolated From Environmental Water in Kolkata, India

Clinical and Environmental Vibrio cholerae Non-O1, Non-O139 Strains from Australia Have Similar Virulence and Antimicrobial Resistance Gene Profiles

Conversion of a recA-Mediated Non-toxigenic Vibrio cholerae O1 Strain to a Toxigenic Strain Using Chitin-Induced Transformation

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