Vibrio parahaemolyticus associated with cholera-like diarrhea among patients in North Jakarta, Indonesia

The trade-off of Vibrio parahaemolyticus between bacteriophage resistance and growth competitiveness

Vibrio parahaemolyticus is a food-borne pathogen, which is often isolated from various seafood products. In this study, two kinds of bacteriophages was isolated from the offshore sediments samples. The anti-phage mutant strain were obtained after seventeen rounds of co-culture of Vibrio parahaemolyticus and mixed bacteriophage, multigroup sequencing was carried out on spontaneous the anti-phage mutant strain and the wild-type strain. We used the Sanger sequencing to verify the accuracy of the mutation sites. Biolog GEN III MicroPlates were used to evaluate the metabolic capacity of wild-type strains and the anti-phage mutant strain. In this study, we found that with flaG gene (slight homology to N terminus of multiple flagellins) mutated, making the bacteriophage unable to absorb to the cell surface of the host. And, the growth competitiveness of the anti-phage mutant strain is lower than the wild-type strain. These results indicated that the fitness cost, including loss of the growth competitiveness, constitutes a barrier to the prevalence of these defense mechanisms. And the selection pressure on different anti-phage strategies depends on the trade-off between mortality imposed by bacteriophages and fitness cost of the defense strategy under the given environmental conditions. In conclusion, this study provides valuable insights into the phage-host interaction and phage resistance in Vibrio parahaemolyticus. Our study provided knowledge for the evolutionary adaption of bacteria against the bacteriophage, which could add more information to understand the phage resistance mechanism before applying in the industry.

Distribution and antibiotic resistance of vibrio population in an urbanized tropical lake-the Vembanad-in the southwest coast of India

Among the diverse Vibrio spp. autochthonous to coastal ecosystems, V. cholerae, V. fluvialis, V. vulnificus and V. parahaemolyticus are pathogenic to humans. Increasing sea-surface temperature, sea-level rise and water-related disasters associated with climate change have been shown to influence the proliferation of these bacteria and change their geographic distribution. We investigated the spatio-temporal distribution of Vibrio spp. in a tropical lake for 1 year at a 20-day interval. The abundance of Vibrio spp. was much higher during the south-west monsoon in 2018, when the lake experienced a once-in-a-century flood. The distribution of Vibrio spp. was influenced by salinity (r = 0.3, p < 0.001), phosphate (r = 0.18, p < 0.01) and nitrite (r = 0.16, p < 0.02) in the water. We isolated 470 colonies of Vibrio-like organisms and 341 could be revived further and identified using 16S rRNA gene sequencing. Functional annotations showed that all the 16 Vibrio spp. found in the lake could grow in association with animals. More than 60% of the isolates had multiple antibiotic resistance (MAR) index greater than 0.5. All isolates were resistant to erythromycin and cefepime. The proliferation of multiple antibiotic-resistant Vibrio spp. is a threat to human health. Our observations suggest that the presence of a diverse range of Vibrio spp. is favoured by the low-saline conditions brought about by heavy precipitation. Furthermore, infections caused by contact with Vibrio-contaminated waters may be difficult to cure due to their multiple antibiotic resistances. Therefore, continuous monitoring of bacterial pollution in the lakes is essential, as is the generation of risk maps of vibrio-infested waters to avoid public contact with contaminated waters and associated disease outbreaks.

Isolation and Characterization of a Lytic Vibrio parahaemolyticus Phage vB_VpaP_GHSM17 from Sewage Samples

Vibrio parahaemolyticus is a major foodborne pathogen and the main cause of diarrheal diseases transmitted by seafood such as fish, shrimp, and shellfish. In the current study, a novel lytic phage infecting V. parahaemolyticus, vB_VpaP_GHSM17, was isolated from the sewage of a seafood market, Huangsha, Guangzhou, and its morphology, biochemistry, and taxonomy features were identified. Morphological observation revealed that GHSM17 had an icosahedral head with a short, non-contractile tail. The double-stranded DNA genome of GHSM17 consisted of 43,228 bp with a GC content of 49.42%. In total, 45 putative ORFs were identified in the GHSM17 genome. Taxonomic analysis indicated GHSM17 belonging to genus Maculvirus, family Autographiviridae. In addition, GHSM17 was stable over a wide range of temperatures (20-60 °C) and pH (5-11) and was completely inactivated after 70 min of ultraviolet irradiation. The bacterial inhibition assay revealed that GHSM17 could inhibit the growth of V. parahaemolyticus within 8 h. The results support that phage GHSM17 may be a potential candidate in the biological control of V. parahaemolyticus contamination in aquaculture.

Diagnosis, Management, and Future Control of Cholera

Cholera, caused by Vibrio cholerae, persists in developing countries due to inadequate access to safe water, sanitation, and hygiene. There are approximately 4 million cases and 143,000 deaths each year due to cholera. The disease is transmitted fecally-orally via contaminated food or water. Severe dehydrating cholera can progress to hypovolemic shock due to the rapid loss of fluids and electrolytes, which requires a rapid infusion of intravenous (i.v.) fluids. The case fatality rate exceeds 50% without proper clinical management but can be less than 1% with prompt rehydration and antibiotics. Oral cholera vaccines (OCVs) serve as a major component of an integrated control package during outbreaks or within zones of endemicity. Water, sanitation, and hygiene (WaSH); health education; and prophylactic antibiotic treatment are additional components of the prevention and control of cholera. The World Health Organization (WHO) and the Global Task Force for Cholera Control (GTFCC) have set an ambitious goal of eliminating cholera by 2030 in high-risk areas.

Distribution and antimicrobial resistance of Vibrio parahaemolyticus isolated from fish and shrimp aquaculture farms along the Korean coast

The present study investigated the distribution and antimicrobial susceptibility patterns of Vibrio parahaemolyticus in water samples and aquatic animals (fish and shrimp) from major aquaculture farms along the Korean coast in 2018. V. parahaemolyticus is the most common pathogen causing seafood-borne illness. The strain was detected in 34.7% of all samples tested, and was detected at higher levels during summer to autumn when the water temperature is higher. Although more than 90.0% of V. parahaemolyticus isolates were sensitive to 13 of the 15 antimicrobials tested, which is useful for treating V. parahaemolyticus infectious disease, the isolates exhibited higher resistance to two antibiotics (colistin and ampicillin), which should be excluded as treatment options for these infections. Koreans typically enjoy consuming raw seafood. To reduce the potential human health risk of raw seafood consumption, the prevalence and antimicrobial resistance of V. parahaemolyticus in aquaculture environments should be continuously valuated.

Characterization of Pathogenic Vibrio parahaemolyticus Isolated From Fish Aquaculture of the Southwest Coastal Area of Bangladesh

Vibrio parahaemolyticus is a major foodborne pathogen responsible for significant economic losses in aquaculture and a threat to human health. Here, we explored the incidence, virulence potential, and diversity of V. parahaemolyticus isolates from aquaculture farms in Bangladesh. We examined a total of 216 water, sediment, Oreochromis niloticus (tilapia), Labeo rohita (rui), and Penaeus monodon (shrimp) samples from the aquaculture system where 60.2% (130/216) samples were positive for V. parahaemolyticus. Furthermore, we identified 323 V. parahaemolyticus strains from contaminated samples, 17 of which were found positive for trh, a virulence gene. Four isolates out of the 17 obtained were able to accumulate fluid in the rabbit ileal loop assay. The correlation between the contamination of V. parahaemolyticus and environmental factors was determined by Pearson correlation. The temperature and salinity were significantly correlated (positive) with the incidence of V. parahaemolyticus. Most of the pathogenic isolates (94.1%) were found resistant to ampicillin and amoxicillin. O8: KUT was the predominant serotype of the potentially pathogenic isolates. ERIC-PCR reveals genetic variation and relatedness among the pathogenic isolates. Therefore, this region-specific study establishes the incidence of potential infection with V. parahaemolyticus from the consumption of tilapia, rui, and shrimp raised in farms in Satkhira, Bangladesh, and the basis for developing strategies to reduce the risk for diseases and economic burden.

Rapid identification and detection of Vibrio parahaemolyticus via different types of modus operandi with LAMP method in vivo

Purpose

Vibrio parahaemolyticus, an easy-ignored food-borne pathogen, can cause bacterial outbreaks and human disease during early-stage infection. In this study, we aimed to evaluate the detection efficiency of loop-mediated isothermal amplification (LAMP) as an emerging technique to directly detect V. parahaemolyticus infection in mammalian hosts and assess its potential in clinical applications.

Methods

A LAMP assay was used for rapid identification of V. parahaemolyticus in a variety of mouse models in which animals were infected via the digestive tract, wounds, or through general infection, and the results were compared with routine analytical methods.

Results

Our results confirmed that the LAMP assay was capable of detecting V. parahaemolyticus in different mouse organs independent of the source of bacteria, although its sensitivity depended on the route of infection and the organ affected. Foodborne-derived V. parahaemolyticus was the most sensitive route, with the small intestine being the most sensitive organ. The LAMP assay indicated that V. parahaemolyticus that spread through the blood stream had the most serious consequences during early-stage infection. Positive LAMP results were identified in all blood samples from i.v. injected mice. Furthermore, the LAMP method could directly detect trace quantities of V. parahaemolyticus in fresh peripheral blood while conventional methods failed to do so, thereby shortening the time-to-result from days to minutes.

Conclusions

In this study, we demonstrated that the LAMP assay was effective in speeding up the detection of V. parahaemolyticus. Instead of being a secondary method to assist in the clinic, the LAMP assay has potential for use as the primary technique for rapid detection of V. parahaemolyticus in the future.

Isolation and Characterization of the Novel Phages vB_VpS_BA3 and vB_VpS_CA8 for Lysing Vibrio parahaemolyticus

Accumulating evidence has indicated that the multiple drug resistant Vibrio parahaemolyticus may pose a serious threat to public health and economic concerns for humans globally. Here, two lytic bacteriophages, namely vB_VpS_BA3 and vB_VpS_CA8, were isolated from sewage collected in Guangzhou, China. Electron microscopy studies revealed both virions taxonomically belonged to the Siphoviridae family with icosahedral head and a long non-contractile tail. The double-stranded DNA genome of phage BA3 was composed of 58648 bp with a GC content of 46.30% while phage CA8 was 58480 bp with an average GC content of 46.42%. In total, 85 putative open reading frames (ORFs) were predicted in the phage BA3 genome while 84 were predicted in that of CA8. The ORFs were associated with phage structure, packing, host lysis, DNA metabolism, and additional functions. Furthermore, average nucleotide identity analysis, comparative genomic features and phylogenetic analysis revealed that BA3 and CA8 represented different isolates but novel members of the family, Siphoviridae. Regarding the host range of the 61 V. parahaemolyticus isolates, BA3 and CA8 had an infectivity of 8.2 and 36.1%, respectively. Furthermore, ∼100 plaque-forming units (pfu)/cell for phage BA3 and ∼180 pfu/cell for phage CA8 were determined to be the viral load under laboratory growth conditions. Accordingly, the phage-killing assay in vitro revealed that phage CA8 achieved approximately 3.65 log unit reductions. The present results indicate that CA8 is potentially applicable for biological control of multidrug resistant V. parahaemolyticus.

Abundance, antimicrobial resistance, and virulence of pathogenic Vibrio strains from molluscan shellfish farms along the Korean coast

To reduce the outbreaks caused by the major pathogenic Vibrio species, V. parahaemolyticus, V. vulnificus, and V. cholerae, the distribution, antibiotic resistance, and virulence of these Vibrio strains were monitored in shellfish and seawater along the Korean coast. Among the Vibrio strains, V. parahaemolyticus was the most abundant species; during summer, this strain showed a substantial increase that correlated with the water temperature. Although >99.0% of the Vibrio species isolates were sensitive to seven antimicrobials recommended by the Center for Disease Control and Prevention for the treatment of Vibrio infections, multiple-antibiotic resistance to at least three antimicrobials was found in 14.3% to 50.0% of each Vibrio species. Among V. parahaemolyticus isolates, 14.3% were positive for the trh gene, whereas only 1% was positive for the tdh gene. These results should aid in implementing proper precautions to avoid potential human health risks associated with exposure to pathogenic Vibrio species.

Prevalence, antimicrobial susceptibility and plasmid profiling of Vibrio spp. isolated from cultured groupers in Peninsular Malaysia

BACKGROUND

Numerous prevalence studies of Vibrio spp. infection in fish have been extensively reported worldwide, including Malaysia. Unfortunately, information on the prevalence of Vibrio spp. in groupers (Epinephelus spp.) is limited. In this study, groupers obtained from nine farms located at different geographical regions in Malaysia were sampled for the presence of pathogenic Vibrio spp. and their susceptibility profiles against seven antibiotics.

RESULTS

Out of 270 grouper samples, 195 (72%) were detected with the presence of Vibrio spp. Vibrio communis showed highest prevalence in grouper (28%), followed by V. parahaemolyticus (25%), V. alginolyticus (19%), V. vulnificus (14%), V. rotiferianus (3%), Vibrio sp. (3%), V. campbellii (2%), V. mytili (2%), V. furnissii (2%), V. harveyi (1%), V. tubiashii (1%), V. fluvialis (0.3%) and V. diabolicus (0.3%). Assessment on the antibiotic susceptibility profiles of the Vibrio spp. revealed that majority of the isolates were susceptible to tetracycline, streptomycin, erythromycin and bacitracin, but resistance to ampicillin, penicillin G and vancomycin. The mean MAR index of the Vibrio isolates was 0.51, with 85% of the isolates showed MAR index value of higher than 0.2. Results indicate that the Vibrio spp. were continuously exposed to antibiotics. Furthermore, the plasmid profiles of Vibrio spp. showed that 38.7% of the isolates harbored plasmid with molecular weight of more than 10 kb, while 61.3% were without plasmid. During curing process, Vibrio spp. lost their plasmid, but remained resistant to ampicillin, penicillin G, bacitracin and vancomycin while a few isolates remained resistant to erythromycin, streptomycin and tetracycline. The results suggested that the resistance to antibiotics in isolated Vibrio spp. might be due to chromosomal and plasmid borne.

CONCLUSIONS

This study demonstrates the prevalence of Vibrio spp. in groupers and the distribution of multidrug resistance strains that could be of concern to the farmers in Malaysia. In addition, data from this study can be further used in fish disease management plan.

Culture-dependent and metagenomic analysis of lesser horseshoe bats' gut microbiome revealing unique bacterial diversity and signatures of potential human pathogens

Bats are highly diverse and ecologically important mammals. They harbor various bacteria, viruses, and fungal communities that are either beneficial or potentially pathogenic. Extensive metagenomic studies in bats are limited, particularly for the gut, and to date, there are no reports on the bacterial diversity of Rhinolophus monoceros from Meghalaya, India. There are limited studies on the isolation of potential harmful or beneficial bacteria and their interactions with the environment through culture-dependent approaches. Therefore, high-throughput screening was used to understand the population structure, genetic diversity, and ecological role of the microorganisms. High-throughput sequencing of the 16S rRNA marker for gene mapping showed that the gut samples constitute a diverse group of bacteria that is dominated by Proteobacteria, followed by Firmicutes. The bacterial genera Corynebacterium and Mycobacterium were also observed in the Illumina dataset. Illumina sequencing revealed eight bacterial phyla composed of 112 genera. The metagenomic analysis of the OTUs from the gut revealed diverse bacterial communities as well as zoonotic and human pathogens. There were differences in the bacterial communities between the two methods used in this study, which could be related to host specificity, diet, and habitat. The culture-dependent technique resulted in the isolation of 35 bacterial isolates, of which Bacillus cereus and B. anthracis are well-known bacterial pathogens that show virulent traits including hemolytic and proteolytic activities. Pseudomonas stutzeri is an opportunistic human pathogen that was also isolated and showed similar traits. Antibiotic sensitivity tests were performed on all 35 isolates, and different antibiotics were used for Gram-positive and -negative bacteria. The result showed that some isolates are resistant to antibiotics such as penicillin G and Cefoxitin. This report on gut bacterial communities could attract interest in the possibility of isolating and characterizing bacteria for the production of antibiotics, enzymes, plant growth promoters, and probiotics. However, the presence of potential pathogenic bacteria that may impose health hazards cannot be ignored and needs to be studied further.

First detection of the plasmid-mediated colistin resistance gene mcr-1 in virulent Vibrio parahaemolyticus

The plasmid-mediated colistin resistance gene mcr-1 has been identified in various Enterobacteriaceae species, which poses a great challenge to the public health. The present study aimed to investigate the prevalence of mcr-1 in Vibrio parahaemolyticus isolated from food samples in China, and to conduct a comprehensive analysis on the molecular characterization of V. parahaemolyticus isolate carrying mcr-1-harboring plasmid. A total of 646 V. parahaemolyticus strains isolated from 2531 food samples collected in retail markets in 34 different cities in China were screened for colistin resistance. Of the 646 V. parahaemolyticus isolates tested, 25 (2.5%) exhibited colistin resistance. The mcr-1 gene was detected in one colistin-resistant V. parahaemolyticus isolate, VP181, obtained from a shrimp sample collected in Hong Kong. The mcr-1 gene was located on a transferable IncX4 plasmid with size of ~40 kb. A Class A β-lactamase gene, bla_CARB-17 and the plasmid-mediated quinolone resistance (PMQR) gene qnrVC5 were detected in the mcr-1-positive V. parahaemolyticus isolate VP181. Virulence gene assays indicated that tdh was detected in VP181 by PCR. This is the first report of the occurrence of plasmid-encoded mcr-1 in virulent V. parahaemolyticus strain. Our findings indicate horizontal transfer of this gene to non-Enterobacteriaceae gram-negative bacteria, which warrants further investigation because of the public health threat it poses.

Occurrence, virulence, and antimicrobial resistance of Vibrio parahaemolyticus isolated from bivalve shellfish farms along the southern coast of Korea

Vibrio parahaemolyticus is the most common pathogen causing seafood-borne illnesses in Korea. The present study evaluated the occurrence, virulence, and antimicrobial resistance of V. parahaemolyticus in seawater and bivalves obtained in 2016 from the southern coast of Korea, an important region for commercial aquaculture industries, especially the Korean raw seafood culture. V. parahaemolyticus was detected in 87 of 160 (54.4%) bivalve samples and in 32 of 130 (24.5%) seawater samples. Especially high levels were detected during summer to early autumn. All the seawater and bivalves contained less than 2 and 5% of the tdh and trh genes of the isolates, respectively, and seawater isolates possessed two fewer genes than the bivalve isolates. Of 23 antimicrobials tested, three agents (ofloxacin, norfloxacin, and trimethoprim/sulfamethoxazole) effectively treated V. parahaemolyticus illness due to the sensitivity of the isolates. The isolates were highly resistant to ampicillin, however, excluding it as a treatment option. More than half of the isolates exhibited resistance to at least three antimicrobials. These findings indicate the importance of an integrated monitoring and surveillance program noting the occurrence, virulence, and antimicrobial resistance patterns of V. parahaemolyticus in various aquatic sources for preventing human health risks from seafood consumption.

Discovery on Antibiotic Resistance Patterns of Vibrio parahaemolyticus in Selangor Reveals Carbapenemase Producing Vibrio parahaemolyticus in Marine and Freshwater Fish

Vibrio parahaemolyticus, a Gram-negative halophilic bacterium is often associated with fish and fishery products, thus causing gastroenteritis in humans upon ingestion of contaminated food. V. parahaemolyticus has become a globally well-known pathogen with yearly reported cases in many countries. This study aimed to discover the antibiotic resistance patterns of V. parahaemolyticus as well as detect Carbapenem resistant isolates from marine and freshwater fish in Selangor. A total of 240 freshwater and marine fish samples collected from wet market and supermarket in Selangor were tested for the presence of V. parahaemolyticus. All the fish samples were determined positive for V. parahaemolyticus using conventional microbiological culture-based method. The toxR gene were detected via polymerase chain reaction (PCR) in 165/240 (69%) isolates. The two-virulence factor of V. parahaemolyticus, thermostable direct hemolysin (tdh) and TDH-related hemolysin (trh) was screened via PCR. As such, four isolates were trh+and none were tdh+. Majority of the isolates presented high resistance to ampicillin (88%), amikacin (64%), and kanamycin (50%). In addition, this study identified 19-imipenem resistant isolates isolated from freshwater and marine fish samples. Further analysis of these 19-imipenem resistant isolates revealed that the resistance toward imipenem was plasmid mediated after plasmid curing assay. The multiple antibiotics resistance index was >0.2 for 70% of the isolates. In summary, the results confirm the presence of V. parahaemolyticus in freshwater and marine fish samples in Selangor, Malaysia. To our best knowledge, this is the first report discovering the antibiotic resistant patterns and Carbapenem-resistant isolates of V. parahaemolyticus isolated from marine and freshwater fish samples in Selangor.

Vibrio Parahaemolyticus: A Leading Cause of Infectious Diarrhoea in Hong Kong

Vibrio parahaemolyticus is one of the commonest pathogens responsible for infectious diarrhoea in Asia. This article highlights recent findings from a retrospective study in an A&E Department in Hong Kong, and reviews current literature in regard to the epidemiological features and laboratory investigations. Prevention, prompt diagnosis and treatment are discussed. Vibrio parahaemolyticus gastroenteritis causes significant morbidity, and is much more prevalent in the summer season. Compared to other bacterial gastroenteritis, patients with this condition may present relatively sooner after the onset of diarrhoea. To ensure prompt detection of outbreaks, an appropriate stool culture medium specific for Vibrio spp. should be used.

Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma) in Malaysia

Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from <3 to >10⁵ MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >10⁵ MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk assessment model to estimate health risks associated with the consumption of short mackerels contaminated with pathogenic V. parahaemolyticus.

Antimicrobial resistance of Vibrio parahaemolyticus and Vibrio alginolyticus strains isolated from farmed fish in Korea from 2005 through 2007

The antimicrobial resistance patterns to 15 antimicrobial agents of Vibrio parahaemolyticus and Vibrio alginolyticus isolated from farmed fishes, including olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), were investigated from 2005 through 2007. A total of 218 V. parahaemolyticus isolates and 153 V. alginolyticus isolates were obtained from the 180 fish samples collected from fish farms located along the southern coast of Korea. We found that 65.1% of V. parahaemolyticus and 85.6% of V. alginolyticus isolates showed antimicrobial resistance against more than one antimicrobial agent. The prevalence of resistance in V. parahaemolyticus isolates to ampicillin was highest (57.8%), followed by resistance to rifampin (11.9%), streptomycin (8.7%), and trimethoprim (6.4%). V. alginolyticus isolates were also most resistant to ampicillin (75.2%), followed by tetracycline (15.0%), trimethoprim (12.4%), and rifampin (9.8%). The prevalence of multiresistance to four or more antimicrobials was higher in V. alginolyticus (11.1%) than in V. parahaemolyticus (5%). Antimicrobial resistance rates per isolate of V. parahaemolyticus and V. alginolyticus possessing virulence genes were not different from those of the rest of the isolates.

Antibiotic susceptibility profiles of some Vibrio strains isolated from wastewater final effluents in a rural community of the Eastern Cape Province of South Africa

BACKGROUND

To evaluate the antibiogram and antibiotic resistance genes of some Vibrio strains isolated from wastewater final effluents in a rural community of South Africa. V. vulnificus (18), V. metschnikovii (3), V. fluvialis (19) and V. parahaemolyticus (12) strains were isolated from final effluents of a wastewater treatment plant (WWTP) located in a rural community of South Africa. The disk diffusion method was used for the characterization of the antibiogram of the isolates. Polymerase chain reaction (PCR) was employed to evaluate the presence of established antibiotic resistance genes using specific primer sets.

RESULTS

The Vibrio strains showed the typical multidrug-resistance phenotype of an SXT element. They were resistant to sulfamethoxazole (Sul), trimethoprim (Tmp), cotrimoxazole (Cot), chloramphenicol (Chl), streptomycin (Str), ampicillin (Amp), tetracycline (Tet) nalidixic acid (Nal), and gentamicin (Gen). The antibiotic resistance genes detected includes dfr18 and dfrA1 for trimethoprim; floR, tetA, strB, sul2 for chloramphenicol, tetracycline, streptomycin and sulfamethoxazole respectively. Some of these genes were only recently described from clinical isolates, demonstrating genetic exchange between clinical and environmental Vibrio species.

CONCLUSIONS

These results demonstrate that final effluents from wastewater treatment plants are potential reservoirs of various antibiotics resistance genes. Moreover, detection of resistance genes in Vibrio strains obtained from the wastewater final effluents suggests that these resistance determinants might be further disseminated in habitats downstream of the sewage plant, thus constituting a serious health risk to the communities reliant on the receiving waterbodies.

Determinants of carriage of resistant Escherichia coli in the Indonesian population inside and outside hospitals

OBJECTIVES

Antibiotic resistance is a worldwide healthcare problem exacerbated by antibiotic use and transmission of resistant bacteria. Not much is known about resistance in commensal flora and about determinants for resistance in Indonesia. This study analysed recent antibiotic use as well as demographic, socioeconomic, disease-related and healthcare-related determinants of rectal carriage of resistant Escherichia coli in the community and in hospitals in Indonesia.

METHODS

Carriers of susceptible E. coli were compared with carriers of E. coli with resistance to any of the tested antibiotics. Logistic regression analysis was performed to determine which variables were associated with carriage of resistant E. coli. Individuals in the community with varying levels of contact with healthcare institutions and hospitalized patients were analysed as separate populations.

RESULTS AND CONCLUSIONS

Of 3275 individuals (community 2494, hospital 781), 54% carried resistant E. coli. Recent antibiotic use was the most important determinant of resistance in both populations [community: odds ratio (OR) 1.8, 95% confidence interval (95% CI) 1.5-2.3; hospital: OR 2.5, 95% CI 1.6-3.9]. In the community, hospitalization (OR 2.4, 95% CI 2.0-3.0), diarrhoeal symptoms (OR 1.9, 95% CI 1.3-2.7) and age under 16 years (adults: OR 0.4, 95% CI 0.3-0.5) were associated with carriage of resistant E. coli. For hospitalized patients, having no health insurance was associated with less resistance (OR 0.6, 95% CI 0.4-0.9) and differences were observed between hospitals (Semarang: OR 2.2, 95% CI 1.5-3.3) and departments (Paediatrics: OR 4.3, 95% CI 1.7-10.7). Further research is needed to investigate whether transmission is responsible for these differences.

Detection ofVibrio parahaemolyticusin cockle (Anadara granosa) by PCR

This study aimed to determine the occurrence of Vibrio parahaemolyticus in cockles (Anadara granosa) at a harvesting area and to detect the presence of virulent strains carrying the thermostable direct hemolysin (tdh) and TDH-related hemolysin genes (trh) using PCR. Of 100 samples, 62 were positive for the presence of V. parahaemolyticus with an MPN (most probable number) value greater than 3.0 (>1100 MPN per g). The PCR analysis revealed 2 samples to be positive for the tdh gene and 11 to be positive for the trh gene. Hence, these results demonstrate the presence of pathogenic V. parahaemolyticus in cockles harvested in the study area and reveal the potential risk of illness associated with their consumption.

The burden of diarrhoea, shigellosis, and cholera in North Jakarta, Indonesia: findings from 24 months surveillance

Background

In preparation of vaccines trials to estimate protection against shigellosis and cholera we conducted a two-year community-based surveillance study in an impoverished area of North Jakarta which provided updated information on the disease burden in the area.

Methods

We conducted a two-year community-based surveillance study from August 2001 to July 2003 in an impoverished area of North Jakarta to assess the burden of diarrhoea, shigellosis, and cholera. At participating health care providers, a case report form was completed and stool sample collected from cases presenting with diarrhoea.

Results

Infants had the highest incidences of diarrhoea (759/1 000/year) and cholera (4/1 000/year). Diarrhea incidence was significantly higher in boys under 5 years (387/1 000/year) than girls under 5 years (309/1 000/year; p < 0.001). Children aged 1 to 2 years had the highest incidence of shigellosis (32/1 000/year). Shigella flexneri was the most common Shigella species isolated and 73% to 95% of these isolates were resistant to ampicillin, trimethoprim-sulfamethoxazole, chloramphenicol and tetracycline but remain susceptible to nalidixic acid, ciprofloxacin, and ceftriaxone. We found an overall incidence of cholera of 0.5/1 000/year. Cholera was most common in children, with the highest incidence at 4/1 000/year in those less than 1 year of age. Of the 154 V. cholerae O1 isolates, 89 (58%) were of the El Tor Ogawa serotype and 65 (42%) were El Tor Inaba. Thirty-four percent of patients with cholera were intravenously rehydrated and 22% required hospitalization. V. parahaemolyticus infections were detected sporadically but increased from July 2002 onwards.

Conclusion

Diarrhoea causes a heavy public health burden in Jakarta particularly in young children. The impact of shigellosis is exacerbated by the threat of antimicrobial resistance, whereas that of cholera is aggravated by its severe manifestations.

Plasmid profiling and antibiotic resistance of Vibrio strains isolated from cultured penaeid shrimp

Resistance to different antibiotics was found in 26 of the 30 strains analyzed, more than 70% of the strains analyzed were resistant to carbenicillin and ampicillin and a significant correlation was found between the resistance to both antibiotics. Plasmids were found in 80% of the strains analyzed, and 11 different plasmid profiles were observed. The most common profile obtained had only a 21.2-kbp plasmid, a significant correlation was found between the presence of this plasmid and resistance to carbenicillin, although some exceptions could be detected. Plasmids were cured from a cephalothin resistant strain and reintroduced into the plasmid-free cell and into Escherichia coli DH5alpha, both strains gained resistance to this antibiotic.

Spectrum of vibrio species associated with acute diarrhea in North Jakarta, Indonesia

Vibrio spp was isolated from 1024 (21.2%) of 4820 diarrhea patients admitted to a community hospital in North Jakarta from 1996 through 1998. Vibrio cholerae O1 (49.5%) and V. parahaemolyticus (30.1%) comprised the major species isolated, followed by V. cholerae non-O1 (16.9%), and V. fluvialis (9.4%). In 938 (19.4%) patients, Vibrio was found as single isolate. Multiple infections were detected in 86 (1.8%) patients. A small number of V. furnisii, V. metschnikovii, V. mimicus and V. hollisae were also isolated. No V. cholerae O139 was detected. The majority of patients with Vibrio spp. infections were adults between the ages of 20 to 45 years. No Vibrio spp. was isolated from infants <1 year old in this study. In vitro antibiotic susceptibility testing revealed no antibiotic resistance associated with the 507 V. cholerae O1 isolates tested, except for colistin (100%). These data implicate Vibrio spp. as a major cause of diarrhea in this region.