Infections due to non-O1 Vibrio cholerae in southern Taiwan: predominance in cirrhotic patients

High Mortality With Non-O1/Non-O139 Vibrio cholera Bacteraemia in Patients With Cirrhosis

Background

Data on non-O1/non-O139 Vibrio cholera (NOVC) infection in liver disease is limited. We studied the clinical features and outcome of patients with cirrhosis with non-NOVC bacteraemia and/or spontaneous bacterial peritonitis (SBP) when compared to non-extended spectrum beta lactamase (non-ESBL) Escherichia coli (E. coli).

Methods

Hospital information system of patients with cirrhosis admitted with bacteraemia and/or SBP from 2010 to 2020 was searched to include patients with NOVC infection. Non-ESBL E. coli bacteraemia/bacterascites were chosen as a comparator group, matched for the date of admission within 5 days of index case. Propensity score matching (PSM) was done for patient's age and Child score to compare outcome at discharge between NOVC-infected and E. coli-infected cirrhotic patients.

Results

There were 2545 patients admitted with bacteraemia and/or SBP during the study period; 29 had NOVC isolated (M:F = 23:6; age: 39, 18-54 years; median, range; model for end-stage liver disease [MELD] score: 25, 12-38; Child score: 11, 10-12.5) from either blood (26), ascites (3), or both (8). Of these, 26 isolates were pan-sensitive to antibiotic sensitivity tests. Fifty-three patients with non-ESBL E. coli were isolated (M: F = 43:10; age: 48; 18-69 years; MELD score: 25, 20-32; Child score:12,11-13) from blood (31), ascites (17), or both (5) within the selected time frame. Of these, 48 isolates were sensitive to the empirical antibiotics initiated.After PSM, in comparison with 29 non-ESBL E. coli patients (age: 41, 18-55 years; MELD score: 24, 19-31; Child score: 12, 11-13), NOVC patients had higher incidence of circulatory failure at admission (14 [49 %] vs 4 [13 %]; P: 0.01) and significantly higher in-hospital mortality (15 [52 %] vs 6 [20 %];P: 0.028].

Conclusions

Bacteraemia due to non-O1/non-O139 strains of V. cholera, is an uncommon cause of bacteraemia or bacterascites in patients with cirrhosis and is associated with high incidence of circulatory failure and significant mortality.

Non-serogroup O1/O139 agglutinable Vibrio cholerae: a phylogenetically and genealogically neglected yet emerging potential pathogen of clinical relevance

Somatic antigen agglutinable type-1/139 Vibrio cholerae (SAAT-1/139-Vc) members or O1/O139 V. cholerae have been described by various investigators as pathogenic due to their increasing virulence potential and production of choleragen. Reported cholera outbreak cases around the world have been associated with these choleragenic V. cholerae with high case fatality affecting various human and animals. These virulent Vibrio members have shown genealogical and phylogenetic relationship with the avirulent somatic antigen non-agglutinable strains of 1/139 V. cholerae (SANAS-1/139- Vc) or O1/O139 non-agglutinating V. cholerae (O1/O139-NAG-Vc). Reports on implication of O1/O139-NAGVc members in most sporadic cholera/cholera-like cases of diarrhea, production of cholera toxin and transmission via consumption and/or contact with contaminated water/seafood are currently on the rise. Some reported sporadic cases of cholera outbreaks and observed change in nature has also been tracable to these non-agglutinable Vibrio members (O1/O139-NAGVc) yet there is a sustained paucity of research interest on the non-agglutinable V. cholerae members. The emergence of fulminating extraintestinal and systemic vibriosis is another aspect of SANAS-1/139- Vc implication which has received low attention in terms of research driven interest. This review addresses the need to appraise and continually expand research based studies on the somatic antigen non-serogroup agglutinable type-1/139 V.cholerae members which are currently prevalent in studies of water bodies, fruits/vegetables, foods and terrestrial environment. Our opinion is amassed from interest in integrated surveillance studies, management/control of cholera outbreaks as well as diarrhea and other disease-related cases both in the rural, suburban and urban metropolis.

A tripartite cytolytic toxin formed by Vibrio cholerae proteins with flagellum-facilitated secretion

Vibrio cholerae, responsible for outbreaks of cholera disease, is a highly motile organism by virtue of a single flagellum. We describe how the flagellum facilitates the secretion of three V. cholerae proteins encoded by a hitherto-unrecognized genomic island. The proteins MakA/B/E can form a tripartite toxin that lyses erythrocytes and is cytotoxic to cultured human cells. A structural basis for the cytolytic activity of the Mak proteins was obtained by X-ray crystallography. Flagellum-facilitated secretion ensuring spatially coordinated delivery of Mak proteins revealed a role for the V. cholerae flagellum considered of particular significance for the bacterial environmental persistence. Our findings will pave the way for the development of diagnostics and therapeutic strategies against pathogenic Vibrionaceae.

The protein MakA was discovered as a motility-associated secreted toxin from Vibrio cholerae. Here, we show that MakA is part of a gene cluster encoding four additional proteins: MakB, MakC, MakD, and MakE. MakA, MakB, and MakE were readily detected in culture supernatants of wild-type V. cholerae, whereas secretion was very much reduced from a flagellum-deficient mutant. Crystal structures of MakA, MakB, and MakE revealed a structural relationship to a superfamily of bacterial pore-forming toxins. Expression of MakA/B/E in Escherichia coli resulted in toxicity toward Caenorhabditis elegans used as a predatory model organism. None of these Mak proteins alone or in pairwise combinations were cytolytic, but an equimolar mixture of MakA, MakB, and MakE acted as a tripartite cytolytic toxin in vitro, causing lysis of erythrocytes and cytotoxicity on cultured human colon carcinoma cells. Formation of oligomeric complexes on liposomes was observed by electron microscopy. Oligomer interaction with membranes was initiated by MakA membrane binding followed by MakB and MakE joining the assembly of a pore structure. A predicted membrane insertion domain of MakA was shown by site-directed mutagenesis to be essential for toxicity toward C. elegans. Bioinformatic analyses revealed that the makCDBAE gene cluster is present as a genomic island in the vast majority of sequenced genomes of V. cholerae and the fish pathogen Vibrio anguillarum. We suggest that the hitherto-unrecognized cytolytic MakA/B/E toxin can contribute to Vibrionaceae fitness and virulence potential in different host environments and organisms.

Population Structure and Multidrug Resistance of Non-O1/Non-O139 Vibrio cholerae in Freshwater Rivers in Zhejiang, China

To understand the environmental reservoirs of Vibrio cholerae and their public health significance, we surveyed freshwater samples from rivers in two cities (Jiaxing [JX] and Jiande [JD]) in Zhejiang, China. A total of 26 sampling locations were selected, and river water was sampled 456 times from 2015 to 2016 yielding 200 V. cholerae isolates, all of which were non-O1/non-O139. The average isolation rate was 47.3% and 39.1% in JX and JD, respectively. Antibiotic resistance profiles of the V. cholerae isolates were examined with nonsusceptibility to cefazolin (68.70%, 79/115) being most common, followed by ampicillin (47.83%, 55/115) and imipenem (27.83%, 32/115). Forty-two isolates (36.52%, 42/115) were defined as multidrug resistant (MDR). The presence of virulence genes was also determined, and the majority of the isolates were positive for toxR (198/200, 99%) and hlyA (196/200, 98%) with few other virulence genes observed. The population structure of the V. cholerae non-O1/non-O139 sampled was examined using multilocus sequence typing (MLST) with 200 isolates assigned to 128 STs and 6 subpopulations. The non-O1/non-O139 V. cholerae population in JX was more varied than in JD. By clonal complexes (CCs), 31 CCs that contained isolates from this study were shared with other parts of China and/or other countries, suggesting widespread presence of some non-O1/non-O139 clones. Drug resistance profiles differed between subpopulations. The findings suggest that non-O1/non-O139 V. cholerae in the freshwater environment is a potential source of human infections. Routine surveillance of non-O1/non-O139 V. cholerae in freshwater rivers will be of importance to public health.

Identification of chironomid species as natural reservoirs of toxigenic Vibrio cholerae strains with pandemic potential

Vibrio cholerae causes the fatal cholera diarrhea. Chironomids (Diptera; Chironomidae) are abundant in freshwater aquatic habitats and estuaries and are natural reservoirs of V. cholerae. Until now, only the non-O1/O139 serogroups of V. cholerae were identified in chironomids. Here, we explored whether chironomids are natural reservoirs of V. cholerae O1/O139 serogroups, which are associated with cholera endemics and pandemics. All four life stages of chironomids were sampled from two rivers, and a laboratory culture in Pune, India, and from a pond in Israel. In total, we analyzed 223 chironomid samples. The presence of V. cholerae O1/O139 serogroups was verified using molecular tools. Nine chironomid species were identified; of them, Chironomus circumdatus was the most abundant. The presence of V. cholerae serogroup O1 and the cholera toxin genes were detected in samples from all chironomid species. However, serogroup O139 was detected in only two chironomid species. Besides PCR to detect specific genes, a metagenomic analysis that was performed in three selected C. ramosus larvae, identified a list of virulence genes associated with V. cholerae. The findings provide evidence that chironomids are natural reservoirs of toxigenic V. cholerae O1/O139. Chironomid populations and V. cholerae show biannual peak patterns. A similar pattern is found for cholera epidemics in the Bengal Delta region. Thus, we hypothesize that monitoring chironomids in endemic areas of the disease may provide a novel tool for predicting and preventing cholera epidemics. Moreover, serogroup O139 was detected only in two chironomid species that have a restricted distribution in the Indian subcontinent, possibly explaining why the distribution of the O139 serogroup is limited.

A Fatal Case of Bacteremia Caused by Vibrio cholerae Non-O1/O139

Vibrio cholerae is a pathogen known to cause the waterborne epidemic disease cholera. Overall, V. cholerae O1 or O139 strains produce the cholera toxin that cause gastroenteritis, resulting in watery diarrhea. Most of the enterocolitis caused by V. cholerae can be easily treated with fluid therapy and conservative care. However, V. cholerae non-O1/O139 strains can cause extraintestinal infections, such as wound infection or sepsis, in immunocompromised patients. The clinical course of these infections is very similar to that of V. vulnificus infection. We report about a 52-year-old man without previous underlying disease who was diagnosed with V. cholerae non-O1/O139 infection and died within 72 hours after admission to the intensive care unit.

Intensive care management of a patient with necrotizing fasciitis due to non-O1/O139 Vibrio cholerae after traveling to Taiwan: a case report

Background

Vibrio cholerae are oxidase-positive bacteria that are classified into various serotypes based on the O surface antigen. V. cholerae serotypes are divided into two main groups: the O1 and O139 group and the non-O1/non-O139 group. O1 and O139 V. cholerae are related to cholera infection, whereas non-O1/non-O139 V. cholerae (NOVC) can cause cholera-like diarrhea. A PubMed search revealed that only 16 cases of necrotizing fasciitis caused by NOVC have been recorded in the scientific literature to date. We report the case of a Japanese woman who developed necrotizing fasciitis caused by NOVC after traveling to Taiwan and returning to Japan.

Case presentation

A 63-year-old woman visited our hospital because she had experienced left knee pain for the past 3 days. She had a history of colon cancer (Stage IV: T3N3 M1a) and had received chemotherapy. She had visited Taiwan 5 days previously, where she had received a massage. She was diagnosed with septic shock owing to necrotizing fasciitis. She underwent fasciotomy and received intensive care. She recovered from the septic shock; however, after 3 weeks, she required an above-knee amputation for necrosis and infection. Her condition improved, and she was discharged after 22 weeks in the hospital.

Conclusions

With the increase in tourism, it is important for clinicians to check patients’ travel history. Clinicians should be alert to the possibility of necrotizing fasciitis in patients with risk factors. Necrotizing fasciitis caused by NOVC is severe and requires early fasciotomy and debridement followed by intensive postoperative care.

Three cases of fulminant cellulitis caused by non-O1, non-O139 Vibrio cholerae in Southern Finland

Background: Non-O1, non-O139 Vibrio cholerae is endemic in temperate waters. Most often encountered as the pathogen in transient gastroenteritis, it can also cause severe soft tissue infections. While normally a rare pathogen in Finland, we observed seven cases of non-O1, non-O139 V. cholerae infections in Helsinki University Hospital during the hot summer of 2018. Here we present three of these cases with fulminant V. cholerae cellulitis in detail.Methods: Patients with tissue culture positive soft tissue infections between 2017 and 2019 were identified using a local laboratory database. Patients with severe infections requiring surgical revision were included in this series.Results: Three patients with tissue culture positive non-O1, non-O139 V. cholerae cellulitis were identified. All were treated in the summer of 2018 for fulminant lower leg cellulitis. Two patients were febrile and hemodynamically unstable at presentation. One had septicaemia. Surgical revisions were done within the first week of admission, and defects covered with partial-thickness skin grafts several weeks later. Antibiotic treatment varied and continued until the wounds were healed, between one and over two months in total.

Vibrio cholerae non-O1 bacteraemia: description of three cases in the Netherlands and a literature review

Vibrio cholerae non-O1 serogroup (VCNO) bacteraemia is a severe condition with a high case-fatality rate. We report three cases diagnosed in the Netherlands, identified during a national microbiological congress, and provide a literature review on VCNO bacteraemia. A search strategy including synonyms for 'VCNO' and 'bacteraemia' was applied to PubMed, Medline, Web of Science and Embase databases. The three cases were reported in elderly male patients after fish consumption and/or surface water contact. The literature search yielded 82 case reports on 90 cases and six case series. Thirty case reports were from Asia (30/90; 33%), concerned males (67/90; 74%), and around one third (38/90; 42%) involved a history of alcohol abuse and/or liver cirrhosis The presenting symptom often was gastroenteritis (47/90; 52%) which occurred after seafood consumption in 32% of the cases (15/47).Aside from the most frequent symptom being fever, results of case series concurred with these findings. Published cases also included rare presentations e.g. endophthalmitis and neonatal meningitis. Based on the limited data available, cephalosporins seemed the most effective treatment. Although mainly reported in Asia, VCNO bacteraemia occurs worldwide. While some risk factors for VCNO were identified in this study, the source of infection remains often unclear. Clinical presentation may vary greatly and therefore a quick microbiological diagnosis is indispensable.

Non-O1/non-O139 Vibrio cholerae septicaemia in a Saudi man: a case report

Background. The non-O1/non-O139 serogroups of Vibrio cholerae occur in diverse natural niches, and usually cause mild and self-limiting gastrointestinal illness. However, they have well-documented potential to cause invasive and extra-intestinal infections among immunocompromised patients. Furthermore, their ability to grow in low-salinity surface water, and the existence of asymptomatic human carriers, suggest novel acquisition routes for this unusual infection, even in people without obvious risk factors.

Case presentation. A 62-year-old man presented with epigastric pain, vomiting and fever. The patient had a history of diabetes and cholecystectomy, although our initial examination did not reveal any significant findings that might indicate V. cholerae infection. However, blood cultures subsequently revealed the presence of V. cholerae, which was positively identified using both conventional and modern non-conventional technologies. The identity of the V. cholerae isolate was confirmed using Vitek MS (matrix–assisted laser desorption ionization-time of flight MS) and the FilmArray system, in addition to its initial identification using the Vitek 2 system. The septicaemia was successfully treated using a 14 day course of ciprofloxacin.

Conclusion. The present case highlights the need to remain highly suspicious of non-O1/non-O139 V. cholerae infections in patients with known risk factors, as well as in healthy individuals with epidemiological exposure and compatible clinical symptoms. Special care should be taken to avoid false-positive results from confirmatory laboratory tests, as the organism can grow in fresh water, and the results should be verified using multiple methods.

Vibrio cholerae non-O1, non-O139 bacteraemia associated with pneumonia, Italy 2016

This paper describes an elderly male patient, living in the Veneto Region, Italy, who developed Vibrio cholerae bacteraemia and pneumonia. Some days previously, while on holiday in the Lagoon of Venice, he had been collecting clams in seawater, during which he suffered small abrasions of the skin. On admission to hospital, he was confused, had fever and a cough, but neither diarrhoea nor signs of gastroenteritis were found. Both blood and stool cultures grew V. cholerae of non-O1 non-O-139 type, and the patient recovered after prompt administration of intravenous ceftriaxone for 2 weeks. This clinical case emphasises the role of global warming and climate changes in causing increasing numbers of water-borne infections.

The Role of Vibrio cholerae Haemagglutinin Protease (HAP) in Extra-Intestinal Infection

INTRODUCTION

Based on the diversity of surface O antigen Vibrio cholerae can be classified into 206 serogroups. Vibrio cholerae is the causative agent of cholera and extra intestinal infections like, septicemia, wound infection and haemorrhagic reactions. Pathogenic factors of V. cholerae extra-intestinal infection are yet to be explored.

AIM

To identify the pathogenic factor associated with V. cholerae extra-intestinal infection.

MATERIALS AND METHODS

This study was carried out between April, 2007 to October 2007 in National Institute of Cholera and Enteric Diseases (NICED). Haemagglutinin Protease (HAP), a major secreted proteolytic enzyme, was purified from the culture supernatant of Vibrio cholerae O1 strain C6709 after removal of outer membrane vesicles using a single step ion-exchange chromatography. Function of HAP was characterized by animal model, like, subcutaneous mouse assay, basement membrane component's degradation assays and tissue culture assays.

RESULT

When suckling mouse was subcutaneously injected with culture supernatant of C6709 strain or purified HAP in both cases, distinct in vivo haemorrhagic response along with histopathological changes like necrosis of the capillaries and muscle layer, acute myofibre degeneration as well as moderate number of erythrocyte scattered through the skin, capillary necrosis, acute myofiber degeneration and necrosis of muscle layer were found. When Tryptic Soy Broth (TSB) media was used, the haemorrhagic effects in suckling mouse were not detectable. The major protein components, laminin and collagen, of basement membrane comprising of vascular endothelial cells, were degraded by HAP. Purified HAP showed cell rounding effects on Int 407 cells.

CONCLUSION

Result indicates that HAP may be a causative agent of Vibrio cholerae mediated extra-intestinal infection. This study confirms that Vibrio cholera as a sole pathogen can cause the extra-intestinal infection. This information is important for public health notification. Besides this, result indicates appropriate testing for Vibrio cholerae and intervention are important for the patient management.

Necrotizing fasciitis due to Vibrio cholerae non-O1/non-O139 after exposure to Austrian bathing sites

We report on two cases of necrotizing fasciitis of the lower leg due to nontoxigenic Vibrio cholerae (V. cholerae). A 73-year-old woman (case 1) and an 80-year-old man (case 2) were hospitalized with symptoms of necrotizing fasciitis on July 18 and August 15, 2015, respectively. In both cases, symptoms started the day after swimming in local ponds. Swabs gained intraoperatively and a blood culture from the male patient, yielded V. cholerae non-O1/non-O139, negative for cholera toxin gene ctx and positive for hemolysin genes hlyA and hlyB. Water samples taken from pond A on August 17, 2015 (32 days after exposure of case 1) and from pond B on August 20, 2015 (7 days after exposure of case 2) yielded non-O1/non-O139 V. cholerae in most-probable numbers of > 11,000 per 100 ml each. The occurrence of two cases of necrotizing fasciitis within a 1 month period related to two Austrian non-saline bathing waters, previously not known to harbor V. cholerae, is probably linked to the prevailing extreme weather conditions (heat wave, drought) this summer in Austria. While case 1 was discharged in good clinical condition after 73 days, case 2 died after four months of hospitalization. Public health authorities are challenged to assess the effects of long-term climate change on pathogen growth and survival in continental bodies of fresh water.

Non-O1, non-O139 Vibrio cholerae bacteremic skin and soft tissue infections

BACKGROUND

Non-O1, non-O139 Vibrio cholerae can cause sporadic cases of gastroenteritis and extra-intestinal invasive infections, following exposure to contaminated seawater or freshwater or after consumption of raw seafood. Bacteremic infections with skin and soft tissue manifestations are uncommon and in most cases are associated with liver cirrhosis, haematologic malignancies, diabetes mellitus and other immunosuppressed conditions.

METHODS

The medical literature was reviewed and we found 47 published cases of non-O1, non-O139 Vibrio cholerae bacteremic skin and soft tissue infections. A fatal case of bacteremia with bullous cellulitis in a 43-year-old patient with liver cirrhosis is described, which is the first reported in Greece.

RESULTS

From January 1974 to May 2015, a total of 48 patients with non-O1, non-O139 Vibrio cholerae bacteremia with skin and soft tissue infections were reported. Males predominated. Liver cirrhosis, chronic liver disease and alcohol abuse were common comorbidities. The soft tissue lesions most commonly described were localised cellulitis, with or without bullous and haemorrhagic lesions (66.7%), while necrotising fasciitis was more rare (29.2%). Of the 48 patients with non-O1, non-O139 V. cholerae bacteremic skin and soft tissue infections, 20 (41.7%) died despite treatment.

CONCLUSION

Although rarely encountered, non-O1, non-O139 Vibrio cholerae should be included in the differential diagnosis of bacteremic skin and soft tissue infections in patients with underlying illnesses and epidemiologic risk factors. Timely and appropriate antibiotic and surgical treatments are important in the management of the infection.

Non-O1, non-O139 Vibrio cholerae bacteraemia: case report and literature review

Non-O1, non-O139 Vibrio cholerae (NOVC) are increasingly frequently observed ubiquitous microorganisms occasionally responsible for intestinal and extra-intestinal infections. Most cases involve self-limiting gastroenteritis or ear and wound infections in immunocompetent patients. Bacteraemia, which have been described in patients with predisposing factors, are rare and poorly known, both on the clinical and therapeutic aspects. We describe a case of NOVC bacteraemia and a systematic literature review in PubMed conducted up to November 2014 using a combination of the following search terms: “Vibrio cholerae non-O1” and “bacter(a)emia”. The case was a 70 year-old healthy male subject returning from Senegal and suffering from NOVC bacteraemia associated with liver abscesses. Disease evolution was favourable after 2 months’ therapy (ceftriaxone then ciprofloxacin). Three hundred and fifty cases of NOVC bacteraemia have been identified in the literature. The majority of patients were male (77 %), with a median age of 56 years and presenting with predisposing conditions (96 %), such as cirrhosis (55 %) or malignant disease (20 %). Diarrhoea was inconstant (42 %). Mortality was 33 %. The source of infection, identified in only 25 % of cases, was seafood consumption (54 %) or contaminated water (30 %). Practitioners should be aware of these infections, in order to warn patients with predisposing conditions, on the risk of ingesting raw or undercooked seafood or bathing in potentially infected waters.

Clinical manifestations of non-O1 Vibrio cholerae infections

BACKGROUND

Infections caused by non-O1 Vibrio cholera are uncommon. The aim of our study was to investigate the clinical and microbiological characteristics of patients with non-O1 V. cholera infections.

METHODS

The clinical charts of all patients with non-O1 V. cholera infections and who were treated in two hospitals in Taiwan were retrospectively reviewed.

RESULTS

From July 2009 to June 2014, a total of 83 patients with non-O1 V. cholera infections were identified based on the databank of the bacteriology laboratories of two hospitals. The overall mean age was 53.3 years, and men comprised 53 (63.9%) of the patients. Liver cirrhosis and diabetes mellitus were the two most common underlying diseases, followed by malignancy. The most common type of infection was acute gastroenteritis (n = 45, 54.2%), followed by biliary tract infection (n = 12, 14.5%) and primary bacteremia (n = 11, 13.3%). Other types of infection, such as peritonitis (n = 5, 6.0%), skin and soft tissue infection (SSTI) (n = 5, 6.0%), urinary tract infection (n = 3, 3.6%) and pneumonia (2, 2.4%), were rare. July and June were the most common months of occurrence of V. cholera infections. The overall in-hospital mortality of 83 patients with V. cholera infections was 7.2%, but it was significantly higher for patients with primary bacteremia, hemorrhage bullae, acute kidney injury, acute respiratory failure, or admission to an ICU. Furthermore, multivariate analysis showed that in-hospital mortality was significantly associated with acute respiratory failure (odds ratio, 60.47; 95% CI, 4.79-763.90, P = 0.002).

CONCLUSIONS

Non-O1 V. cholera infections can cause protean disease, especially in patients with risk factors and during warm-weather months. The overall mortality of 83 patients with non-O1 V. cholera infections was only 7.2%; however, this value varied among different types of infection.

Non-O1, non-O139 Vibrio cholerae bacteraemia in an Australian population

This retrospective case series identifies the largest cohort of non-O1, non-O139 Vibrio cholerae bacteraemia in an Australian population from 2000 to 2013. We examine the risk factors, epidemiology, clinical presentations and mortality of non-O1, non-O139 V. cholerae bacteraemia in Victoria and compare them with published cases in the literature. This case series highlights the pathogenic potential of non-O1, non-O139 V. cholerae and identifies possible associations with host (underlying chronic liver disease and malignancy) and environmental factors (contaminated water supply and raw seafood). Clinicians should be aware of the morbidity and mortality associated with invasive non-O1, non-O139 V. cholerae infections, particularly in immunocompromised patients.

Isolation and characterization of Vibrio cholerae isolates from seafood in Hat Yai City, Songkhla, Thailand

Seafood has been identified as an important source of Vibrio cholerae in Thailand, especially in the Southern coastal region. In this study, we isolated and characterized V. cholerae from seafood obtained from several markets in Hat Yai city, Southern Thailand. A total of 100 V. cholerae isolates were obtained from 55 of 125 seafood samples. The dominant serotype was non-O1/non-O139. Polymerase chain reaction (PCR) analysis was used to detect the presence of pathogenesis-related genes. The stn/sto and hlyA El Tor virulence genes were detected in 20% and 96% of the isolates, respectively. None of the isolates were positive for the ctxA, tcpA, zot, and ace genes. Only 6% of the isolates carried the T3SS gene (vcsV2); however, the majority of the isolates (96%) carried the T6SS gene (vasH). Representative isolates (n=35) that exhibited various virulence gene patterns were randomly selected and analyzed for their hemolytic activity, antibiotic susceptibility, biofilm formation, and genotype. Hemolytic activity using sheep red blood cells was detected in only one of the hlyA-negative isolates. Apart from ampicillin, all isolates were pansusceptible to five test antibiotics. Biofilm production was observed in most of the isolates, and there was no difference in the presence of a biofilm between the smooth and rugose isolates. Using the enterobacterial repetitive intergenic consensus-PCR method, clonal relationships were observed among the isolates that exhibited identical virulence gene patterns.

Comparison of skin and soft tissue infections caused by Vibrio and Aeromonas species

BACKGROUND

The aim of this study was to compare skin and soft tissue infections (SSTIs) caused by Vibrio and Aeromonas spp.

METHODS

Patients whose cultures yielded Vibrio or Aeromonas spp. from July 2004 to June 2010 were retrieved from the computerized database of the bacteriology laboratory at a hospital in southern Taiwan. The medical records were reviewed for all patients fulfilling the criteria of monomicrobial Vibrio or Aeromonas spp. SSTIs and the clinical characteristics were analyzed.

RESULTS

During the study period, there were 28 patients with Vibrio spp. and 26 patients with Aeromonas spp., respectively. Vibrio vulnificus (n=25) and A. hydrophila (n=14) were the most common spp. There were no significant differences in age, gender, underlying diseases between patients with Vibrio and Aeromonas SSTIs. In comparison to Aeromonas SSTIs, more patients with Vibrio SSTIs were complicated with acute respiratory failure (39.3% vs. 3.8%, p=0.002) and required intensive care unit admission (50.0% vs. 7.7%, p<0.001). Furthermore, patients with Aeromonas SSTIs had a higher likelihood of discharge alone within 30 days than Vibrio SSTIs (p=0.049). The difference in in-hospital mortality among the two groups was not statistically significant (p=0.11).

CONCLUSION

Both Aeromonas and Vibrio spp. cause SSTIs in southern Taiwan and the pathogenicity of Vibrio spp. might be higher than Aeromonas spp.

Two cases of bacteriemia caused by nontoxigenic, non-O1, non-O139 Vibrio cholerae isolates in Ho Chi Minh City, Vietnam

The toxigenic bacterium Vibrio cholerae belonging to the O1 and O139 serogroups is commonly associated with epidemic diarrhea in tropical settings; other diseases caused by this environmental pathogen are seldom identified. Here we report two unassociated cases of nonfatal, nontoxigenic V. cholerae non-O1, non-O139 bacteremia in patients with comorbidities in Ho Chi Minh City, Vietnam, that occurred within a 4-week period.

Monomicrobial Aeromonas and Vibrio bacteremia in cirrhotic adults in southern Taiwan: Similarities and differences

BACKGROUND/PURPOSE

Aeromonas and Vibrio are important water-borne pathogens causing substantial morbidity and mortality in cirrhotic patients in Taiwan, but the differences in clinical manifestations of Aeromonas and Vibrio bacteremia have not been reported in detail.

METHODS

From January 2003 to September 2013, cirrhotic patients with monomicrobial Aeromonas or Vibrio bacteremia at a medical center in Taiwan were included in this study.

RESULTS

The study population consisted of 77 cirrhotic patients with Aeromonas bacteremia and 48 patients with Vibrio bacteremia. Both pathogens clustered during the summer season; Vibrio bacteremia was more correlated with higher temperatures (Vibrio: r(2) = 0.95, p < 0.0001; Aeromonas: r(2) = 0.74, p = 0.006) and was associated with ingestion of undercooked seafood (p = 0.03) or cutaneous exposure (p < 0.001). Vibrio bacteremia mainly occurred in mildly or moderately decompensated cirrhosis (Child-Pugh class A and B: 45.8% vs. 20.8%, p = 0.003), and caused more soft-tissue infections (31.3% vs. 5.2%; p < 0.001) and renal dysfunction (1.6 ± 1.2 mg/dL vs. 1.3 ± 0.8 mg/dL, p = 0.006). Sepsis-related mortality was similar in the cases of Vibrio and Aeromonas bacteremia (14.6% vs. 14.3%, p = 0.96), but those with Vibrio bacteremia underwent a fulminant course, as evidenced by a shorter time from bacteremia onset to death (3.1 days vs. 8.2 days, p = 0.04).

CONCLUSION

In cirrhotic patients, bacteremia caused by Aeromonas and Vibrio species clustered in summer months and caused similar mortality, but Vibrio bacteremia led to a more severe and fulminant sepsis.

Genomic and phenotypic characterization of Vibrio cholerae non-O1 isolates from a US Gulf Coast cholera outbreak

Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

Molecular diversity and predictability of Vibrio parahaemolyticus along the Georgian coastal zone of the Black Sea

Vibrio parahaemolyticus is a leading cause of seafood-related gastroenteritis and is also an autochthonous member of marine and estuarine environments worldwide. One-hundred seventy strains of V. parahaemolyticus were isolated from water and plankton samples collected along the Georgian coast of the Black Sea during 28 months of sample collection. All isolated strains were tested for presence of tlh, trh, and tdh. A subset of strains were serotyped and tested for additional factors and markers of pandemicity. Twenty-six serotypes, five of which are clinically relevant, were identified. Although all 170 isolates were negative for tdh, trh, and the Kanagawa Phenomenon, 7 possessed the GS-PCR sequence and 27 the 850 bp sequence of V. parahaemolyticus pandemic strains. The V. parahaemolyticus population in the Black Sea was estimated to be genomically heterogeneous by rep-PCR and the serodiversity observed did not correlate with rep-PCR genomic diversity. Statistical modeling was used to predict presence of V. parahaemolyticus as a function of water temperature, with strongest concordance observed for Green Cape site samples (Percent of total variance = 70, P < 0.001). Results demonstrate a diverse population of V. parahaemolyticus in the Black Sea, some of which carry pandemic markers, with increased water temperature correlated to an increase in abundance of V. parahaemolyticus.

Non-O1, non-O139 Vibrio cholerae sepsis in a patient with nephrotic syndrome

Non-O1, non-O139 Vibrio cholerae is an encapsulated bacterium, ubiquitous in the marine environment and generally considered to be non-pathogenic. However, it is known to cause diarrheal illness, wound infection, and bacteremia in immunocompromised hosts. Here we have describe non-O1, non-O139 V. cholerae sepsis in a patient with nephrotic syndrome following exposure to sea-water. Interestingly, the exposure occurred remotely 4 months prior to the onset of nephrotic syndrome. The occurrence of florid sepsis after a prolonged interval from the time of exposure is peculiar and raises the possibility of an association between occult Vibrio sepsis and nephrotic syndrome.

Population structure and evolution of non-O1/non-O139 Vibrio cholerae by multilocus sequence typing

Pathogenic non-O1/non-O139 Vibrio cholerae strains can cause sporadic outbreaks of cholera worldwide. In this study, multilocus sequence typing (MLST) of seven housekeeping genes was applied to 55 non-O1/non-O139 isolates from clinical and environmental sources. Data from five published O1 isolates and 17 genomes were also included, giving a total of 77 isolates available for analysis. There were 66 sequence types (STs), with the majority being unique, and only three clonal complexes. The V. cholerae strains can be divided into four subpopulations with evidence of recombination among the subpopulations. Subpopulations I and III contained predominantly clinical strains. PCR screening for virulence factors including Vibrio pathogenicity island (VPI), cholera toxin prophage (CTXΦ), type III secretion system (T3SS), and enterotoxin genes (rtxA and sto/stn) showed that combinations of these factors were present in the clinical isolates with 85.7% having rtxA, 51.4% T3SS, 31.4% VPI, 31.4% sto/stn (NAG-ST) and 11.4% CTXΦ. These factors were also present in environmental isolates but at a lower frequency. Five strains previously mis-identified as V. cholerae serogroups O114 to O117 were also analysed and formed a separate population with V. mimicus. The MLST scheme developed in this study provides a framework to identify sporadic cholera isolates by genetic identity.

Fatal non-O1, non-O139 Vibrio cholerae septicaemia in a patient with chronic liver disease

A 49-year-old male with underlying liver disease presented with fever and signs of sepsis. Non-O1/non-O139 Vibrio cholerae was isolated from his blood culture, which was positive for the hlyA and toxR genes. We report this fatal case of non-O1/non-O139 V. cholera sepsis and review the literature on non-O1/non-O139 V. cholerae sepsis in patients with chronic liver disease.

Non-toxigenic Vibrio cholerae bacteraemia: case report and review of the literature

Vibrio cholerae is a serious public health problem worldwide, but in the UK, V. cholerae infections are rare. Here, we report a case of V. cholerae bacteraemia in an elderly patient. To our knowledge, this is the first non-travel-related V cholerae bacteraemia in the UK.

Molecular analysis of non-O1/non-O139 Vibrio cholerae isolated from hospitalised patients in China

BACKGROUND

Cholera is still a significant public health issue in developing countries. The aetiological agent is Vibrio cholerae and only two serogroups, O1 and O139, are known to cause pandemic or epidemic cholera. In contrast, non-O1/non-O139 V. cholerae has only been reported to cause sporadic cholera-like illness and localised outbreaks. The aim of this study was to determine the genetic diversity of non-O1/non-O139 V. cholerae isolates from hospitalised diarrhoeal patients in Zhejiang Province, China.

RESULTS

In an active surveillance of enteric pathogens in hospitalised diarrhoeal patients, nine non-O1/non-O139 V. cholerae isolates were identified from 746 diarrhoeal stool samples at a rate of 1.2%. These isolates and an additional 31 isolates from sporadic cases and three outbreaks were analysed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). PFGE divided the isolates into 25 PFGE types while MLST divided them into 15 sequence types (STs). A single ST, ST80, was predominant which persisted over several years in different cities and caused two outbreaks in recent years. Antibiotic resistance varied with the majority of the isolates resistant to sulphamethoxazole/trimethoprim and nearly all isolates either resistant or intermediate to erythromycin and rifampicin. None of the isolates carried the cholera toxin genes or toxin co-regulated pilus genes but the majority carried a type III secretion system as the key virulence factor.

CONCLUSIONS

Non-O1/non-O139 V. cholerae is an important contributor to diarrhoeal infections in China. Resistance to commonly used antibiotics limits treatment options. Continuous surveillance of non-O1/non-O139 V. cholerae is important for control and prevention of diarrhoeal infections.

Detection of Vibrio cholerae in environmental waters including drinking water reservoirs of Azerbaijan

Cholera, a globally prevalent gastrointestinal disease, remains a persistent problem in many countries including the former Soviet republics of the Caucasus region where sporadic outbreaks occurred recently. Historically, this region has experienced cholera during every pandemic since 1816; however, no known comprehensive evaluation of the presence of Vibrio cholerae in surface waters using molecular methods has been done. Here we present the first report of the presence of V. cholerae in surface waters of Azerbaijan and its seasonality, using a combination of bacteriological and molecular methods. Findings from the present study indicate a peak in the presence of V. cholerae in warmer summer months relative to colder winter months. In the Caspian Sea, water temperature when optimal for growth of V. cholerae was significantly associated with detection of V. cholerae. Vibrio cholerae was simultaneously detected at freshwater sites including two water reservoirs. Most importantly, detection of V. cholerae in these water reservoirs, the source of municipal drinking water, poses a potential health risk to the population due to the limited and insufficient treatment of water in Azerbaijan. Routine monitoring of environmental waters used for recreational purposes, and especially drinking water reservoirs, is highly recommended as a measure for public health safety.

Vibrio cholerae non-O1 and non-O139 bacteremia in a non-traveler Portuguese cirrhotic patient: first case report

Bacteremia due to Vibrio cholerae non-O1 and non-O139 is a rare condition and potentially fatal. We report a case of bacteremia due to V. cholerae non-O1 and non-O139 in a Portuguese male with Hepatitis C cirrhosis, admitted due to acute diarrhea, after consuming shrimp. He had no recent travels. To our knowledge, this is the first reported case of bacteremia due to V. cholerae non-O1 and non-O139 in Portugal.

Incidence of Aeromonas bacteremia in Southern Taiwan: vibrio and Salmonella bacteremia as comparators

The aim of the investigation was to describe the incidence of Aeromonas bacteremia in a city with a population of about 1.87 million inhabitants, located in southern Taiwan, between 2008 and 2010. Such data were compared with the incidences of Vibrio and Salmonella bacteremia in the same period and the incidence of Aeromonas bacteremia in other countries in the literature. The data revealed the average annual incidences of bacteremia due to Aeromonas, Vibrio, and Salmonella species were 76, 38, and 103 cases/million inhabitants, respectively. The incidence of Aeromonas bacteremia was higher than those in Western countries.

Spontaneous bacterial empyema due to non-O1, non-O139 Vibrio cholerae in a cirrhotic patient with hepatocellular carcinoma

Vibrio cholerae is known as a common etiology of epidemic diarrheal disease and rarely causes extra-intestinal infections. In this report, we described a cirrhotic patient with hepatocellular carcinoma who developed spontaneous bacterial empyema due to non-O1, non-O139 V. cholerae. The patient was successfully treated with antimicrobial agents and percutaneous drainage.

Nontoxigenic Vibrio cholerae Septicemia in an Immunocompromised Patient

We report a recent case of non-O1, non-O139, nontoxigenic Vibrio cholerae septicemia in a post-liver-transplant immunocompromised patient associated with prior seafood consumption. Non-O1, non-O139 V. cholerae strains have been reported in several cases of extraintestinal infections and seem to be emerging infectious agents especially in patients with immunocompromising conditions.

Acute Otitis due to Vibrio fluvialis after Swimming

A 40-year-old female presented with purulent exudate through the left auditive duct and pain in the left ear region, which intensified during mastication. After collection of the pus from the left ear lesion, amoxicillin-clavulanic acid for seven days was prescribed for a presumed diagnosis of acute otitis. Four days later, the pus culture grew V. fluvialis which is further identified by API 20E identification system (bioMérieux). Following the successful completion of a course of antibiotics, the patient recovered completely and without complication. To the best of our knowledge, this is the first case of Vibrio fluvialis otitis after swimming in an immunocompetent patient.

Bacterial infections other than spontaneous bacterial peritonitis in cirrhosis

Cirrhotic patients are immunocompromised with a high risk of infection. Proinflammatory cytokines and hemodynamic circulation derangement further facilitate the development of serious consequences of infections. Other than spontaneous bacterial peritonitis, bacteremia and bacterial infections of other organ systems are frequently observed. Gram-negative enteric bacteria are the most common causative organism. Other bacterial infections, such as enterococci, Vibrio spp., Aeromonas spp., Clostridium spp., Listeria monocytogenes, Plesiomonas shigelloides and Mycobacterium tuberculosis are more prevalent and more virulent. Generally, intravenous third generation cephalosporins are recommended as empirical antibiotic therapy. Increased incidences of gram-positive and drug-resistant organisms have been reported, particularly in hospital-acquired infections and in patients receiving quinolones prophylaxis. This review focuses upon epidemiology, microbiology, clinical features and treatment of infections in cirrhosis other than spontaneous bacterial peritonitis, including pathogen-specific and liver disease-specific issues.

[A case of liver abscess and bacteremia caused by Vibrio cholerae non-O1]

Vibrio cholerae non-O1 have caused several well-studied food-borne outbreaks of gastroenteritis and also have been responsible for sporadic cases of otitis media, wound infection, and bacteremia. Few cases of liver abscess caused by Vibrio cholerae non-O1 have been reported. A 73-year-old man with underlying diabetes mellitus was admitted with nausea, vomiting, dyspepsia and febrile sensation. We identified Vibrio cholerae non-O1 in his blood cultures and multiple hepatic microabscess on abdominal computed tomography. He was treated with systemic antibiotics and fluid therapy, but died due to septic shock on sixth day. We report here, a case of liver abscess with bacteremia due to Vibrio cholerae non-O1 in a patient with diabetes mellitus.

Occurrence of potentially pathogenic vibrios and related environmental factors in Songkhla Lake, Thailand

Vibrios are halophilic bacteria that are ubiquitous in marine environments. Their occurrence in tropical lakes has rarely been investigated. In this study, the predominance and diversity of Vibrio spp. was investigated over a 12-month period in a coastal lagoon, Songkhla Lake, in southern Thailand. Water samples were collected at 2 stations in the estuary near Yor Island in Songkhla Lake. The predominant vibrios were detected by a culture-based method, using thiosulfate–citrate–bile salt–sucrose agar and CHROMagar Vibrio. The diversity of Vibrio spp. was evaluated using denaturant density gradient electrophoresis (DGGE). The highest numbers of total vibrios and Vibrio parahaemolyticus in both areas were observed during the summer. There was no significant correlation between the numbers of vibrios, including V. parahaemolyticus, and either the water temperature or plankton density. Variations in Vibrio species were observed with changes in salinity. Vibrio parahaemolyticus and V. cholerae non-O1/non-O139 were detected during the rainy season when the salinity dropped to nearly 0 parts per thousand. In both areas, V. alginolyticus was the most prominent species detected by the culture method, whereas Vibrio parahaemolyticus was detected by DGGE, every month. Other Vibrio spp. of potential public health concern were also detected by the culture method; they included V. vulnificus , V. fluvialis , and V. mimicus .

The management of hospitalized patients with cirrhosis: the Mount Sinai experience and a guide for hospitalists

BACKGROUND

Cirrhosis and chronic liver disease carry appreciable morbidity and mortality. Cirrhotic patients frequently require hospitalization and their care is both extremely complex and labor-intensive.

AIM

We seek to provide a review for gastroenterologists, hepatologists, internists, and hospitalists on the approach to care in patients hospitalized for complications related to end-stage liver disease.

METHODS

The Mount Sinai Medical Center's inpatient liver service has developed an integrated team approach for cirrhotic patients and throughout the years has educated fellows-in-training and medical house staff on both the treatment principles and "pearls" in managing the hospitalized cirrhotic patient. We reviewed the literature and provide recommendations on the management of complications of end-stage liver disease. Additionally, we provide a review of the protocols used at our institution in the care for cirrhotic patients.

RESULTS

Major complications of advanced liver disease include infection, ascites, spontaneous bacterial peritonitis, hepatic encephalopathy, portal hypertension, variceal hemorrhage, hepatorenal syndrome, and hepatocellular carcinoma. Management of these complications involves selecting the appropriate diagnostic studies and prompt administration of therapy.

CONCLUSIONS

There are many complications of cirrhosis. Management of these complications can be complex and are targeted at stabilizing the patient's clinical condition. Liver transplantation remains the only definitive treatment.