JMM Profile: Vibrio cholerae: an opportunist of human crises

2021 ◽  
Vol 70 (9) ◽  
Author(s):  
Trudy-Ann Grant ◽  
Deepak Balasubramanian ◽  
Salvador Almagro-Moreno

Vibrio cholerae O1 is the aetiological agent of the severe diarrhoeal disease cholera. Annually, there are an estimated 1–4 million cholera cases worldwide and over 140 000 deaths. The primary mode of disease transmission is through the consumption of water or food contaminated with the bacterium. Although cholera patients can be treated effectively using rehydration therapy, the disease remains a major scourge in areas with limited access to clean water and proper sanitation. Its continued prevalence highlights the failure of socioeconomic policies leading to wealth disparities, fragile and dated public infrastructure, and lack of appropriate health surveillance.

Microbiology ◽  
2021 ◽  
Vol 167 (10) ◽  
Author(s):  
Mengting Shi ◽  
Yue Zheng ◽  
Xianghong Wang ◽  
Zhengjia Wang ◽  
Menghua Yang

Vibrio cholerae the causative agent of cholera, uses a large number of coordinated transcriptional regulatory events to transition from its environmental reservoir to the host intestine, which is its preferred colonization site. Transcription of the mannose-sensitive haemagglutinin pilus (MSHA), which aids the persistence of V. cholerae in aquatic environments, but causes its clearance by host immune defenses, was found to be regulated by a yet unknown mechanism during the infection cycle of V. cholerae . In this study, genomic expression library screening revealed that two regulators, VC1371 and VcRfaH, are able to positively activate the transcription of MSHA operon. VC1371 is localized and active in the cell membrane. Deletion of vc1371 or VcrfaH genes in V. cholerae resulted in less MshA protein production and less efficiency of biofilm formation compared to that in the wild-type strain. An adult mouse model showed that the mutants with vc1371 or VcrfaH deletion colonized less efficiently than the wild-type; the VcrfaH deletion mutant showed less colonization efficiency in the infant mouse model. The findings strongly suggested that the two regulators, namely VC1371 and VcRfaH, which are involved in the regulation of MSHA expression, play an important role in V. cholerae biofilm formation and colonization in mice.


2021 ◽  
Vol 70 (11) ◽  
Author(s):  
Mark Philip Bugayong ◽  
Hidemasa Izumiya ◽  
Josie M. Bilar ◽  
Masatomo Morita ◽  
Eiji Arakawa ◽  
...  

Introduction. The Philippines, comprising three island groups, namely, Luzon, Visayas and Mindanao, experienced an increase in cholera outbreaks in 2016. Previous studies have shown that Vibrio cholerae isolates obtained from the Philippines are novel hybrid El Tor strains that have evolved in the country and are clearly distinct from those found in Mozambique and Cameroon. Gap statement. The characterization of the strains isolated from outbreaks has been limited to phenotypic characteristics, such as biochemical and serological characteristics, in most previous studies. Aim. We performed multilocus variable-number tandem repeat (VNTR) analysis (MLVA) for V. cholerae isolates obtained from 2015 to 2016 to further characterize and understand the emergence and dissemination of the strains in the Philippines. Methodology. A total of 139 V . cholerae O1 Ogawa biotype El Tor isolates were obtained from the Philippines during diarrhoeal outbreaks in 18 provinces between 2015 and 2016. VNTR data were analysed to classify the MLVA profiles where the large-chromosome types (LCTs) were applied for grouping. Results. We identified 50 MLVA types among 139 isolates originating from 18 provinces, and 14 LCTs. The distribution of the LCTs was variable, and a few were located in specific areas or even in specific provinces. Based on eBURST analysis, 99 isolates with 7 LCTs and 32 MLVA types belonged to 1 group, suggesting that they were related to each other. LCT A was predominant (n=67) and was isolated from Luzon and Visayas. LCT A had 14 MLVA types; however, it mostly emerged during a single quarter of a year. Eight clusters were identified, each of which involved specific MLVA type(s). The largest cluster involved 23 isolates showing 3 MLVA types, 21 of which were MLVA type A-14 isolated from Negros Occidental during quarter 4 of 2016. Comparative analysis showed that almost all isolates from the Philippines were distinct from those in other countries. Conclusions. The genotypic relationship of the V. cholerae isolates obtained during outbreaks in the Philippines was studied, and their emergence and dissemination were elucidated. MLVA revealed the short-term dynamics of V. cholerae genotypes in the Philippines.


Author(s):  
Deepak Balasubramanian ◽  
Sebastian Murcia ◽  
C. Brandon Ogbunugafor ◽  
Ronnie Gavilan ◽  
Salvador Almagro-Moreno

Cholera is a severe diarrhoeal disease that spreads rapidly and affects millions of people each year, resulting in tens of thousands of deaths. The disease is caused by Vibrio cholerae O1 and is characterized by watery diarrhoea that can be lethal if not properly treated. Cholera had not been reported in South America from the late 1800s until 1991, when it was introduced in Peru, wreaking havoc in one of the biggest epidemics reported to date. Within a year, the disease had spread to most of the Latin American region, resulting in millions of cases and thousands of deaths in all affected countries. Despite its aggressive entry, cholera virtually disappeared from the continent after 1999. The progression of the entire epidemic was well documented, making it an ideal model to understand cholera dynamics. In this review, we highlight how the synergy of socioeconomic, political and ecological factors led to the emergence, rapid spread and eventual disappearance of cholera in Latin America. We discuss how measures implemented during the cholera epidemic drastically changed its course and continental dynamics. Finally, we synthesize our findings and highlight potential lessons that can be learned for efficient and standardized cholera management programmes during future outbreaks in non-endemic areas.


F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 589 ◽  
Author(s):  
Brian Y. Hsueh ◽  
Christopher M. Waters

Cholera infections caused by the gamma-proteobacterium Vibrio cholerae have ravaged human populations for centuries, and cholera pandemics have afflicted every corner of the globe. Fortunately, interventions such as oral rehydration therapy, antibiotics/antimicrobials, and vaccines have saved countless people afflicted with cholera, and new interventions such as probiotics and phage therapy are being developed as promising approaches to treat even more cholera infections. Although current therapies are mostly effective and can reduce disease transmission, cholera outbreaks remain deadly, as was seen during recent outbreaks in Haiti, Ethiopia, and Yemen. This is due to significant underlying political and socioeconomic complications, including shortages of vaccines and clean food and water and a lack of health surveillance. In this review, we highlight the strengths and weaknesses of current cholera therapies, discuss emerging technologies, and argue that a multi-pronged, flexible approach is needed to continue to reduce the worldwide burden of cholera.


2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Thea G. Fennell ◽  
Grace A. Blackwell ◽  
Nicholas R. Thomson ◽  
Matthew J. Dorman

Members of the bacterial genus Vibrio utilize chitin both as a metabolic substrate and a signal to activate natural competence. Vibrio cholerae is a bacterial enteric pathogen, sub-lineages of which can cause pandemic cholera. However, the chitin metabolic pathway in V. cholerae has been dissected using only a limited number of laboratory strains of this species. Here, we survey the complement of key chitin metabolism genes amongst 195 diverse V. cholerae . We show that the gene encoding GbpA, known to be an important colonization and virulence factor in pandemic isolates, is not ubiquitous amongst V. cholerae . We also identify a putatively novel chitinase, and present experimental evidence in support of its functionality. Our data indicate that the chitin metabolic pathway within V. cholerae is more complex than previously thought, and emphasize the importance of considering genes and functions in the context of a species in its entirety, rather than simply relying on traditional reference strains.


2021 ◽  
Vol 7 (10) ◽  
Author(s):  
Japheth A. Opintan ◽  
Robert C. Will ◽  
George K. Kuma ◽  
Mary Osei ◽  
Amos Akumwena ◽  
...  

We investigated the evolution, phylogeny and antimicrobial resistance of Vibrio cholerae O1 isolates (VCO1) from Ghana. Outbreak and environmental sources of VCO1 were characterized, whole-genome sequenced and compared to globally available seventh pandemic (7P) strains of V. cholerae at SNP resolution. Final analyses included 636 isolates. Novel Ghanaian isolates clustered into three distinct clades (clades 1, 2 and 3) in wave 3 of the 7P lineage. The closest relatives of our novel Ghanaian isolates were from Benin, Cameroon, Togo, Niger and Nigeria. All novel Ghanaian isolates were multi-drug resistant. Environmental isolates clustered into clade 2, despite being isolated years later, showing the possibility of persistence and re-emergence of older clades. A lag phase of several years from estimated introduction to reported cases suggests pathogen persistence in the absence of reported cholera cases. These results highlight the importance of deeper surveillance for understanding transmission routes between bordering countries and planning tailored vaccination campaigns in an effort to eradicate cholera.


2021 ◽  
Vol 70 (11) ◽  
Author(s):  
Gian Piero Carboni

During the 1854 cholera outbreak in Florence, Italy, Filippo Pacini documented that the cause of the infection was a bacterium. This conclusion was also independently reached by John Snow during the 1854 cholera outbreak in London. By using an epidemiological method, Snow found that the infection spread through a polluted water network. Snow identified a water pump as the source of the disease. After removing the infected handle of this pump, the cases of cholera rapidly began to decrease. A microscopic examination of the water showed organic impurities but no bacteria. This discovery was ignored during Snow’s lifetime. In contrast, through microscopy during the autopsies of cholera victims, Pacini observed that the disruption of their intestinal mucosa was closely associated with millions of the bacteria that he called Vibrio cholerae . Via histological techniques, Pacini detected that intestinal mucosa reabsorption dysfunction was the cause of debilitating diarrhoea, vomiting, severe dehydration and death. Nevertheless, his discovery of Vibrio cholerae was ignored during Pacini’s lifetime. A survey of Pacini’s autographic manuscripts suggests that Pacini and Snow may have shared mutual knowledge within their respective seminal papers. This survey also facilitates, for the first time, the creation of maps that illustrate the worldwide distribution of Pacini’s cholera papers from 1854 to 1881. The consistent neglect of Pacini’s discovery remains a true enigma.


2014 ◽  
Vol 64 (Pt_9) ◽  
pp. 3208-3214 ◽  
Author(s):  
Paul C. Kirchberger ◽  
Maryann Turnsek ◽  
Dana E. Hunt ◽  
Bradd J. Haley ◽  
Rita R. Colwell ◽  
...  

A Gram-staining-negative, curved-rod-shaped bacterium with close resemblance to Vibrio cholerae , the aetiological agent of cholera, was isolated over the course of several years from coastal brackish water (17 strains) and from clinical cases (two strains) in the United States. 16S rRNA gene identity with V. cholerae exceeded 98 % yet an average nucleotide identity based on genome data of around 86 % and multi locus sequence analysis of six housekeeping genes (mdh, adk, gyrB, recA, pgi and rpoB) clearly delineated these isolates as a distinct genotypic cluster within the V. cholerae – V. mimicus clade. Most standard identification techniques do not differentiate this cluster of isolates from V. cholerae . Only amplification of the ompW gene using V. cholerae -specific primers and a negative Voges–Proskauer test showed a difference between the two clusters. Additionally, all isolated strains differed phenotypically from V. cholerae in their ability to utilize N-acetyl-d-galactosamine and d-glucuronic acid as sole carbon sources. Furthermore, they were generally unable to infect the slime mould Dictyostelium discoideum, a widespread ability in V. cholerae . Based on these clear phenotypic differences that are not necessarily apparent in standard tests as well as average nucleotide identity and phylogeny of protein-coding genes, we propose the existence of a novel species, Vibrio metoecus sp. nov. with the type strain OP3HT ( = LMG 27764T = CIP 110643T). Due to its close resemblance to V. cholerae and the increasing number of strains isolated over the past several years, we suggest that V. metoecus sp. nov. is a relatively common species of the genus Vibrio , isolates of which have been identified as atypical isolates of V. cholerae in the past. Its isolation from clinical samples also indicates that strains of this species, like V. cholerae , are opportunistic pathogens.


mBio ◽  
2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Kimberley D. Seed ◽  
Kip L. Bodi ◽  
Andrew M. Kropinski ◽  
Hans-Wolfgang Ackermann ◽  
Stephen B. Calderwood ◽  
...  

ABSTRACT Lytic bacteriophages are hypothesized to contribute to the seasonality and duration of cholera epidemics in Bangladesh. However, the bacteriophages contributing to this phenomenon have yet to be characterized at a molecular genetic level. In this study, we isolated and sequenced the genomes of 15 bacteriophages from stool samples from cholera patients spanning a 10-year surveillance period in Dhaka, Bangladesh. Our results indicate that a single novel bacteriophage type, designated ICP1 (for the International Centre for Diarrhoeal Disease Research, Bangladesh cholera phage 1 ) is present in all stool samples from cholera patients, while two other bacteriophage types, one novel (ICP2) and one T7-like (ICP3), are transient. ICP1 is a member of the Myoviridae family and has a 126-kilobase genome comprising 230 open reading frames. Comparative sequence analysis of ICP1 and related isolates from this time period indicates a high level of genetic conservation. The ubiquitous presence of ICP1 in cholera patients and the finding that the O1 antigen of lipopolysaccharide (LPS) serves as the ICP1 receptor suggest that ICP1 is extremely well adapted to predation of human-pathogenic V. cholerae O1. IMPORTANCE The severe diarrheal disease cholera is caused by the bacterium Vibrio cholerae, which can be transmitted to humans from the aquatic environment. Factors that affect V. cholerae in the environment can impact the occurrence of cholera outbreaks; one of these factors is thought to be the presence of bacterial viruses, or bacteriophages. Bacteriophages that prey on V. cholerae in the environment, and potentially in humans, have not been extensively genetically characterized. Here, we isolated and sequenced the genomes of bacteriophages from cholera patient stool samples collected over a 10-year period in Dhaka, Bangladesh, a region that suffers from regular cholera outbreaks. We describe a unique bacteriophage present in all samples, infer its evolution by sequencing multiple isolates from different patients over time, and identify the host receptor that shows that the bacteriophage specifically predates the serogroup of V. cholerae responsible for the majority of disease occurrences.


Microbiology ◽  
2021 ◽  
Author(s):  
Erin C. Young ◽  
Jackson T. Baumgartner ◽  
Ece Karatan ◽  
Misty L. Kuhn

Biofilm formation in the human intestinal pathogen Vibrio cholerae is in part regulated by norspermidine, spermidine and spermine. V. cholerae senses these polyamines through a signalling pathway consisting of the periplasmic protein, NspS, and the integral membrane c-di-GMP phosphodiesterase MbaA. NspS and MbaA belong to a proposed class of novel signalling systems composed of periplasmic ligand-binding proteins and membrane-bound c-di-GMP phosphodiesterases containing both GGDEF and EAL domains. In this signal transduction pathway, NspS is hypothesized to interact with MbaA in the periplasm to regulate its phosphodiesterase activity. Polyamine binding to NspS likely alters this interaction, leading to the activation or inhibition of biofilm formation depending on the polyamine. The purpose of this study was to determine the amino acids important for NspS function. We performed random mutagenesis of the nspS gene, identified mutant clones deficient in biofilm formation, determined their responsiveness to norspermidine and mapped the location of these residues onto NspS homology models. Single mutants clustered on two lobes of the NspS model, but the majority were found on a single lobe that appeared to be more mobile upon norspermidine binding. We also identified residues in the putative ligand-binding site that may be important for norspermidine binding and interactions with MbaA. Ultimately, our results provide new insights into this novel signalling pathway in V. cholerae and highlight differences between periplasmic binding proteins involved in transport versus signal transduction.


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