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Fulltext Cholera--still a major health problem

Lim VKE

Med J Malaysia, 1993 Mar;48(1):1-2.
PMID: 8341166
Matched MeSH terms: Cholera/microbiology
Evaluation of intestinal damage caused by V. cholerae O139, an in vivo study

Murugaiah C, Noor NZ, Mustafa S, Manickam R, Pattabhiraman L

Microb Pathog, 2017 Apr;105:25-29.
PMID: 28179117 DOI: 10.1016/j.micpath.2017.02.002

Cholera, a severe form of gastroenteritis, is one of the most widespread diseases in developing countries. The mechanism of intestinal infection caused by V. cholerae O139 remains unclear. In order to explore some morphological aspects of its infection in the intestine including Peyer's patches, we investigated the V. cholerae O139 infection at intestinal site of the rabbit gut-loop model. The electron microscopic analysis revealed denuded mucosal surface with loss of microvilli and integrity of the surface epithelium. Infection of the intestine with V. cholerae O139 induces destruction of villi, microvilli and lining epithelium with exposure of crypts of Lieberkuhn.

Matched MeSH terms: Cholera/microbiology*
Fulltext Non-O1 Vibrio cholerae septicaemia: a case report

Tan KK, Sin KS, Ng AJ, Yahya H, Kaur P

Singapore Med J, 1994 Dec;35(6):648-9.
PMID: 7761898

Non-O1 vibrio cholerae infections are associated with sporadic cases of gastroenteritis and extraintestinal infections. Septicaemia due to non-O1 vibrio cholerae is rare and are mainly reported in adults, particularly in immunocompromised patients. We report a case of non-O1 vibrio cholerae septicaemia and gastroenteritis in an 8-year-old child. The patient presented with bloody diarrhoea, fever and severe dehydration. Non-O1 vibrio cholerae were isolated from blood and stool cultures. The clinical course was uneventful after starting appropriate rehydration and supportive therapy.

Matched MeSH terms: Cholera/microbiology*
Survival of Vibrio cholerae on different finger locations of a volunteer following artificial inoculation

Yap KL, Hu KN

Southeast Asian J Trop Med Public Health, 2008 Jul;39(4):667-75.
PMID: 19058604

The importance of bacteria-suspending media and fingertip positions on the survival of Vibrio cholerae on human fingertips were examined. Vibrios were suspended in phosphate-buffered saline (PBS), PBS with albumin, and PBS with agarose. Each type of preparation was inoculated on the fingerpads, the hyponychia, or the eponychia and lateral nail grooves of the fourth, third and second fingers of a volunteer's hand. The last finger inoculated was immediately washed with PBS and the washing collected for examination ("0 minute" exposure). The third and fourth inoculated fingers were likewise washed for examination 2 and 5 minutes later, respectively. The vibrios obtained from the washings were enumerated by culture. For each of the different groups, which consisted of a different inoculated fingertip position, bacteria-suspending medium and exposure period of 2 or 5 minutes, the proportion of replicate inoculated fingers which retained viable vibrios (isolation rate) and the mean number of surviving vibrios, as a percentage of the inoculated vibrios at "0 minute exposure" (survival rate) were as follows: finger pads: vibrios in PBS, 2 minutes post-inoculation (isolation rate, 25%; mean survival rate, 0.002%); 5 minutes post-inoculation (isolation rate, 0%; mean survival rate, 0%). PBS-albumin: 2 minutes post-inoculation (60%, 0.004%); 5 minutes post-inoculation (40%, 0.03%). PBS-agarose: 2 minutes post-inoculation (100%, 24%); 5 minutes post-inoculation (38%, 0.005%). Lateral nail grooves and eponychia: PBS: 2 minutes post-inoculation (100%, 2.2%); 5 minutes post-inoculation (44%, 0.2%). PBS-agarose: 2 minutes post-inoculation (100%, 32%); 5 minutes post-inoculation (100%, 0.7%). Hyponychia: PBS: 2 minutes post-inoculation (100%, 8%); 5 minutes post-inoculation (100%, 0.2%). PBS-agarose: 2 minutes post-inoculation (100%, 46%); 5 minutes post-inoculation (100%, 8%). The results show that vibrios in moisture-retaining medium (PBS-agarose) and inoculated on a sheltered fingertip locations (hyponychium) have the best survival rates. However, the high survival rate was maintained briefly.

Matched MeSH terms: Cholera/microbiology*
Molecular evidence of clonality amongst Vibrio cholerae O1 biotype El Tor during an outbreak in Malaysia

Vadivelu J, Iyer L, Kshatriya BM, Puthucheary SD

Epidemiol Infect, 2000 Feb;124(1):25-30.
PMID: 10722126

Forty-three clinical strains of V. cholerae O1 biotype E1 Tor were isolated between 3 May and 10 June 1998 during an outbreak in the metropolitan area of Kuala Lumpur and its suburbs. With the exception of three Inaba strains that were restricted to three members of a family, all the others belonged to the Ogawa serotype. The strains were analysed for clonality using ribotyping and pulsed-field gel electrophoresis (PFGE). Two ribotypes, V/B21a and B27, were identified among 40 Ogawa isolates using BglI restriction endonuclease. Ribotype V/B21a has been described previously from Taiwan and Colombia and several Asian countries while B27 has been reported among isolates from Senegal. The three Inaba strains belonged to one ribotype, designated type A, not previously reported. PFGE analysis using NotI revealed that all isolates within a ribotype had identical profiles demonstrating clonality amongst the strains. Dice coefficient analysis of the two Ogawa genotypes revealed 89% similarity on ribotype patterns and 91.3% on PFGE profiles. Ribotype V/B21a isolates were associated with cases from dispersed areas of Kuala Lumpur and its suburbs while ribotype B27 was restricted to cases from one particular area suggesting a common-source outbreak.

Matched MeSH terms: Cholera/microbiology*
Fulltext Tetracycline resistant cholera in Kelantan

Ranjit K, Nurahan M

Med J Malaysia, 2000 Mar;55(1):143-5.
PMID: 11072502 MyJurnal

Sensitivity testing on Vibrio cholerae isolates during an epidemic in 1998 in Kelantan identified strains resistant to tetracycline. This prompted a change in the usual management of cholera in Kelantan. The antibiotic of choice was changed from tetracycline to erythromycin.

Matched MeSH terms: Cholera/microbiology
Fulltext Wings of the common house fly (Musca domestica L.): importance in mechanical transmission of Vibrio cholerae

Yap KL, Kalpana M, Lee HL

Trop Biomed, 2008 Apr;25(1):1-8.
PMID: 18600198

The importance of house fly (Musca domestica L) wings in mechanical transmission of bacteria was studied. A droplet of phosphate-buffered saline containing Vibrio cholerae was rolled along one wing of each house fly. None adhered to the wings but small proportions of the bacterium were isolated from about half the wings. Vibrio cholerae was spread onto the ventral wing surfaces of each unconscious house fly which then was placed inside a bottle. When it regained consciousness, the types of activity it performed over five minutes were noted before the house fly was killed and the bacteria on its wings numerated. Control were house flies killed before inoculation. The proportion of house flies with bacteria on their wings and the mean number of bacteria remaining were significantly less on live house flies than killed controls. Among the live house flies, bacteria were detected on fewer house flies which flew (25%) than those which did not fly (81%). In addition, the mean number of bacteria on the former was significantly less than the latter (5 against 780 colonies). However, both these parameters were not significantly different between the group which performed and the group which did not perform wing grooming; takeoff and alighting over short distances, and somersaulting. Wings of unconscious house flies tethered by their thoraxes were inoculated with V. cholerae. After regaining consciousness, the house flies were allowed to move their wings in flight motions for up to 30 seconds. Small proportions of bacteria remained on all the house flies. House flies were placed in a chamber containing a liquid bait spiked with V. cholerae. After two hours, 10 were removed sequentially and cultured for V. cholerae. The bacterium was isolated from four house flies: two from the legs, and two others from their bodies minus legs and wings. In conclusion, house fly wings do not play an important role in mechanical transmission of bacteria suspended in a non-adhering liquid medium because of the low transfer rate of the bacteria to the wings and poor retention of bacteria on the wings during normal house fly activities.

Matched MeSH terms: Cholera/microbiology
Molecular epidemiologic analysis of Vibrio cholerae O1 isolates by pulsed-field gel electrophoresis

Mahalingam S, Cheong YM, Kan S, Yassin RM, Vadivelu J, Pang T

J Clin Microbiol, 1994 Dec;32(12):2975-9.
PMID: 7883885

Isolates of Vibrio cholerae O1 El Tor from two well-defined cholera outbreaks in Malaysia were analyzed by using pulsed-field gel electrophoresis (PFGE). Isolates from sporadic cases occurring during the same time period were also studied. Digestion of chromosomal DNA from these isolates of V. cholerae O1 with restriction endonucleases NotI (5'-GCGGCCGC-3') and SfiI (5'-GGCCNNNN-3'), followed by PFGE, produced restriction endonuclease analysis (REA) patterns consisting of 13 to 24 bands (ranging in size from 46 to 398 kbp). Analysis of the REA patterns generated by PFGE after digestion with NotI and SfiI suggested the clonal nature and close genetic identity of the isolates obtained during each of the two outbreaks (Dice coefficient, 0.93 to 1.0). Although they had very similar REA patterns, the two outbreak clones were not identical. Isolates of V. cholerae O1 from sporadic cases, on the other hand, appeared to be much more heterogeneous (five different REA patterns detected in the five isolates tested; Dice coefficient, 0.31 to 0.81) than those obtained during the two outbreaks. We conclude that PFGE of V. cholerae O1 chromosomal DNA digested with infrequently cutting restriction endonucleases is a useful method for molecular typing of V. cholerae isolates for epidemiological purposes.

Matched MeSH terms: Cholera/microbiology
Fulltext Genome sequence and comparative genomics analysis of a Vibrio cholerae O1 strain isolated from a cholera patient in Malaysia

Osama A, Gan HM, Teh CS, Yap KP, Thong KL

J Bacteriol, 2012 Dec;194(24):6933.
PMID: 23209200 DOI: 10.1128/JB.01832-12

The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na(+)-driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223.

Matched MeSH terms: Cholera/microbiology*
Occurrence of Vibrio cholerae 01 strains in Southeast Asia resistant to vibriostatic compound 0/129

Mahalingam S, Cheong YM, Kan SK, Pang T

Southeast Asian J Trop Med Public Health, 1993 Dec;24(4):779-80.
PMID: 7939959
Matched MeSH terms: Cholera/microbiology*
Comparison of histopathological features of Vibrio cholerae O1 El Tor and O139 Bengal infections in rabbit intestinal mucosa

Amin A, Ali A, Kurunathan S, Cheong TG, Al-Jashamy KA, Jaafar H, et al.

Histol Histopathol, 2009 05;24(5):559-65.
PMID: 19283664 DOI: 10.14670/HH-24.559

Vibrio cholerae is the causative agent of the infectious disease, cholera. The bacteria adhere to the mucosal membrane and release cholera toxin, leading to watery diarrhea. There are >100 serovars of V. cholerae, but the O1 and O139 serovars are the main causative agents of cholera. The present study aimed to compare the severity of intestinal mucosal infection caused by O1 El Tor and O139 V. cholerae in a rabbit ileal loop model. The results showed that although the fluid accumulation was similar in the loops inoculated with O1 and O139 V. cholerae, the presence of blood was detected only in the loops inoculated with the O139 serovar. Serosal hemorrhage was confirmed by histopathological examination and the loops inoculated with O139 showed massive destruction of villi and loss of intestinal glands. The submucosa and muscularis mucosa of the ileum showed the presence of edema with congested blood vessels, while severe hemorrhage was seen in the muscularis propria layer. The loops inoculated with O1 El Tor showed only minimal damage, with intact intestinal villi and glands. Diffuse colonies of the O139 serovar were seen to have infiltrated deep into the submucosal layer of the intestine. Although the infection caused by the O1 serovar was focal and invasive, it was more superficial than that due to O139, and involved only the villi. These observations were confirmed by immunostaining with O1 and O139 V. cholerae-specific monoclonal antibodies. The peroxidase reaction demonstrated involvement of tissues down to the submucosal layer in O139 V. cholerae infection, while in O1 El Tor infection, the reaction was confined mainly to the villi, and was greatly reduced in the submucosal region. This is the first reported study to clearly demonstrate the histopathological differences between infections caused by the O139 Bengal and O1 El Tor pathogenic serovars of V. cholerae.

Matched MeSH terms: Cholera/microbiology*
Electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere label for detection of Vibrio cholerae

Liew PS, Lertanantawong B, Lee SY, Manickam R, Lee YH, Surareungchai W

Talanta, 2015 Jul 1;139:167-73.
PMID: 25882423 DOI: 10.1016/j.talanta.2015.02.054

Vibrio cholerae is a Gram-negative bacterium that causes cholera, a diarrheal disease. Cholera is widespread in poor, under-developed or disaster-hit countries that have poor water sanitation. Hence, a rapid detection method for V. cholerae in the field under these resource-limited settings is required. In this paper, we describe the development of an electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere (AuNPs-PSA) reporter label. The reporter label mixture was prepared by lyophilization of AuNPs-PSA-avidin conjugate with different types of stabilizers. The best stabilizer was 5% sorbitol, which was able to preserve the dried conjugate for up to 30 days. Three methods of DNA hybridization were compared and the one-step sandwich hybridization method was chosen as it was fastest and highly specific. The performance of the assay using the lyophilized reagents was comparable to the wet form for detection of 1aM to 1fM of linear target DNA. The assay was highly specific for V. cholerae, with a detection limit of 1fM of PCR products. The ability of the sensor is to detect LAMP products as low as 50ngµl(-1). The novel lyophilized AuNPs-PSA-avidin reporter label with electrochemical genosensor detection could facilitate the rapid on-site detection of V. cholerae.

Matched MeSH terms: Cholera/microbiology
Evaluation of the cholera spot test: a chromatographic immunoassay for the rapid detection of cholera antigen

Rohani MY, Hasnidah D, Ong KH

Malays J Pathol, 1998 Jun;20(1):31-3.
PMID: 10879261

A chromatographic immunoassay cholera antigen detection kit, the Cholera Spot test, was evaluated. The test was found to be specific with a sensitivity of 10(6) cfu/ml for the direct detection of V. cholerae in simulated stool specimens and 10 cfu/ml in simulated cotton-tipped swab specimens after overnight incubation in alkaline peptone water. This enables early recognition of cholera cases and their contacts so that prevention and control measures can be promptly instituted.

Matched MeSH terms: Cholera/microbiology
Role of coaggregation in the pathogenicity and prolonged colonisation of Vibrio cholerae

Toh YS, Yeoh SL, Yap IKS, Teh CSJ, Win TT, Thong KL, et al.

Med Microbiol Immunol, 2019 Dec;208(6):793-809.
PMID: 31263955 DOI: 10.1007/s00430-019-00628-3

Cholera is an acute diarrheal illness caused by the Gram-negative bacterium Vibrio cholerae. The pathogen is known for its ability to form biofilm that confers protection against harsh environmental condition and as part of the colonisation process during infection. Coaggregation is a process that facilitates the formation of biofilm. In a preliminary in vitro study, high coaggregation index and biofilm production were found between V. cholerae with human commensals namely Escherichia coli and Enterobacter cloacae. Building upon these results, the effects of coaggregation were further evaluated using adult BALB/c mouse model. The animal study showed no significant differences in mortality and fluid accumulation ratio between treatment groups infected with V. cholerae alone and those infected with coaggregation partnership (V. cholerae with E. coli or V. cholerae with E. cloacae). However, mild inflammation was detected in both partnering pairs. Higher density of V. cholerae was recovered from faecal samples of mice co-infected with E. coli and V. cholerae in comparison with other groups at 24 h post-infection. This partnership also elicited slightly higher levels of interleukin-5 (IL-5) and interleukin-10 (IL-10). Nonetheless, the involvement of autoinducer-2 (AI-2) as the signalling molecules in quorum sensing system is not evident in this study. Since E. coli is one of the common commensals, our result may suggest the involvement of commensals in cholera development.

Matched MeSH terms: Cholera/microbiology*
Fulltext Genetic diversity of toxigenic Vibrio cholerae O1 from Sabah, Malaysia 2015

Zaw MT, Emran NA, Ibrahim MY, Suleiman M, Awang Mohd TA, Yusuff AS, et al.

J Microbiol Immunol Infect, 2019 Aug;52(4):563-570.
PMID: 29428381 DOI: 10.1016/j.jmii.2018.01.003

BACKGROUND: Cholera is an important health problem in Sabah, a Malaysian state in northern Borneo; however, Vibrio cholerae in Sabah have never been characterized. Since 2002, serogroup O1 strains having the traits of both classical and El Tor biotype, designated as atypical El Tor biotype, have been increasingly reported as the cause of cholera worldwide. These variants are believed to produce clinically more severe disease like classical strains.
PURPOSE: The purpose of this study is to investigate the genetic diversity of V.cholerae in Sabah and whether V.cholerae in Sabah belong to atypical El Tor biotype.
METHODS: ERIC-PCR, a DNA fingerprinting method for bacterial pathogens based on the enterobacterial repetitive intergenic consensus sequence, was used to study the genetic diversity of 65 clinical V.cholerae O1 isolates from 3 districts (Kudat, Beluran, Sandakan) in Sabah and one environmental isolate from coastal sea water in Kudat district. In addition, we studied the biotype-specific genetic traits in these isolates to establish their biotype.
RESULTS: Different fingerprint patterns were seen in isolates from these three districts but one of the patterns was seen in more than one district. Clinical isolates and environmental isolate have different patterns. In addition, Sabah isolates harbor genetic traits specific to both classical biotype (ctxB-1, rstRCla) and El Tor biotype (rstRET, rstC, tcpAET, rtxC, VC2346).
CONCLUSION: This study revealed that V.cholerae in Sabah were genetically diverse and were atypical El Tor strains. Fingerprint patterns of these isolates will be useful in tracing the origin of this pathogen in the future.

Matched MeSH terms: Cholera/microbiology*
Ambient temperature detection of PCR amplicons with a novel sequence-specific nucleic acid lateral flow biosensor

Ang GY, Yu CY, Yean CY

Biosens Bioelectron, 2012 Oct-Dec;38(1):151-6.
PMID: 22705404 DOI: 10.1016/j.bios.2012.05.019

In the field of diagnostics, molecular amplification targeting unique genetic signature sequences has been widely used for rapid identification of infectious agents, which significantly aids physicians in determining the choice of treatment as well as providing important epidemiological data for surveillance and disease control assessment. We report the development of a rapid nucleic acid lateral flow biosensor (NALFB) in a dry-reagent strip format for the sequence-specific detection of single-stranded polymerase chain reaction (PCR) amplicons at ambient temperature (22-25°C). The NALFB was developed in combination with a linear-after-the-exponential PCR assay and the applicability of this biosensor was demonstrated through detection of the cholera toxin gene from diarrheal-causing toxigenic Vibrio cholerae. Amplification using the advanced asymmetric PCR boosts the production of fluorescein-labeled single-stranded amplicons, allowing capture probes immobilized on the NALFB to hybridize specifically with complementary targets in situ on the strip. Subsequent visual formation of red lines is achieved through the binding of conjugated gold nanoparticles to the fluorescein label of the captured amplicons. The visual detection limit observed with synthetic target DNA was 0.3 ng and 1 pg with pure genomic DNA. Evaluation of the NALFB with 164 strains of V. cholerae and non-V. cholerae bacteria recorded 100% for both sensitivity and specificity. The whole procedure of the low-cost NALFB, which is performed at ambient temperature, eliminates the need for preheated buffers or additional equipment, greatly simplifying the protocol for sequence-specific PCR amplicon analysis.

Matched MeSH terms: Cholera/microbiology*
Detection of virulence associated genes, haemolysin and protease amongst Vibrio cholerae isolated in Malaysia

Iyer L, Vadivelu J, Puthucheary SD

Epidemiol Infect, 2000 Aug;125(1):27-34.
PMID: 11057956

Eighty-four strains of Vibrio cholerae O1, O139 and non-O1/non-O139 from clinical and environmental sources were investigated for the presence of the toxin co-regulated pilus gene, tcpA, the virulence cassette genes ctxA, zot, ace and cep and also for their ability to elaborate haemolysin and protease. The ctxA and zot genes were detected using DNA-DNA hybridization while the ace, cep and tcpA genes were detected using PCR. Production of haemolysin and protease was detected using mammalian erythrocytes and an agar diffusion assay respectively. Analysis of their virulence profiles showed six different groups designated Type I to Type VI and the major distinguishing factor among these profiles was in the in vitro production of haemolysin and/or protease. Clinical O1, O139 and environmental O1 strains were similar with regard to presence of the virulence cassette genes. All environmental O1 strains with the exception of one were found to possess ctxA, zot and ace giving rise to the probability that these strains may actually be of clinical origin. One strain which had only cep but none of the toxin genes may be a true environmental isolate. The virulence cassette and colonization factor genes were absent in all non-O1/non-O139 environmental strains but production of both the haemolysin and protease was present, indicating that these may be putative virulence factors. These findings suggest that with regard to its pathogenic potential, only strains of the O1 and O139 serogroup that possess the tcpA gene which encodes the phage receptor, have the potential to acquire the CTX genetic element and become choleragenic.

Matched MeSH terms: Cholera/microbiology*
Comparative PCR-based fingerprinting of Vibrio cholerae isolated in Malaysia

Shuan Ju Teh C, Thong KL, Osawa R, Heng Chua K

J Gen Appl Microbiol, 2011;57(1):19-26.
PMID: 21478644

Vibrio cholerae, the causative agent of cholera, is endemic in many parts of the world, especially in countries poor in resources. Molecular subtyping of V. cholerae is useful to trace the regional spread of a clone or multidrug-resistant strains during outbreaks of cholera. Current available PCR-based fingerprinting methods such as Random Amplified Polymorphic DNA (RAPD)-PCR, Enterobacterial Repetitive Intergenic Consensus Sequence (ERIC)-PCR, and Repetitive Extragenic Palindromic (REP)-PCR were used to subtype V. cholerae. However, there are problems for inter-laboratory comparison as these PCR methods have their own limitations especially when different PCR methods have been used for molecular typing. In this study, a Vibrio cholerae Repeats-PCR (VCR-PCR) approach which targets the genetic polymorphism of the integron island of Vibrios was used and compared with other PCR-based fingerprinting methods in subtyping. Forty-three V. cholerae of different serogroups from various sources were tested. The PCR-fingerprinting approaches were evaluated on typeability, reproducibility, stability and discriminatory power. Overall, Malaysian non-O1/non-O139 V. cholerae were more diverse than O1 strains. Four non-O1/non-O139 strains were closely related with O1 strains. The O139 strain in this study shared similarity with strains of both O1 and non-O1/non-O139 serogroups. ERIC-PCR was the most discriminative approach (D value = 0.996). VCR-PCR was useful in discriminating non-O1/non-O139 strains. RAPD-PCR and REP-PCR were less suitable for efficient subtyping purposes as they were not reproducible and lacked stability. The combination of the ERIC-PCR and VCR-PCR may overcome the inadequacy of any one approach and hence provide more informative data.

Matched MeSH terms: Cholera/microbiology
A signal-amplified electrochemical DNA biosensor incorporated with a colorimetric internal control for Vibrio cholerae detection using shelf-ready reagents

Low KF, Zain ZM, Yean CY

Biosens Bioelectron, 2017 Jan 15;87:256-263.
PMID: 27567251 DOI: 10.1016/j.bios.2016.08.064

A novel enzyme/nanoparticle-based DNA biosensing platform with dual colorimetric/electrochemical approach has been developed for the sequence-specific detection of the bacterium Vibrio cholerae, the causative agent of acute diarrheal disease in cholera. This assay platform exploits the use of shelf-stable and ready-to-use (shelf-ready) reagents to greatly simplify the bioanalysis procedures, allowing the assay platform to be more amenable to point-of-care applications. To assure maximum diagnosis reliability, an internal control (IC) capable of providing instant validation of results was incorporated into the assay. The microbial target, single-stranded DNA amplified with asymmetric PCR, was quantitatively detected via electrochemical stripping analysis of gold nanoparticle-loaded latex microspheres as a signal-amplified hybridization tag, while the incorporated IC was analyzed using a simplified horseradish peroxidase enzyme-based colorimetric scheme by simple visual observation of enzymatic color development. The platform showed excellent diagnostic sensitivity and specificity (100%) when challenged with 145 clinical isolate-spiked fecal specimens. The limits of detection were 0.5ng/ml of genomic DNA and 10 colony-forming units (CFU)/ml of bacterial cells with dynamic ranges of 0-100ng/ml (R(2)=0.992) and log10 (1-10(4) CFU/ml) (R(2)=0.9918), respectively. An accelerated stability test revealed that the assay reagents were stable at temperatures of 4-37°C, with an estimated ambient shelf life of 200 days. The versatility of the biosensing platform makes it easily adaptable for quantitative detection of other microbial pathogens.

Matched MeSH terms: Cholera/microbiology
Immunohistochemical, histological and ultrastructural evaluation of protection provided by cholera vaccine against V. cholerae O139

Murugaiah C, Nik Mohd Noor NZ, Al-Talib H, Mustafa S, Manickam R, Pattabhiraman L

Microb Pathog, 2020 Mar;140:103964.
PMID: 31904450 DOI: 10.1016/j.micpath.2020.103964

In our previous study, complete protection was observed in rabbit immunized with 1 × 1010 CFU of live attenuated VCUSM21P vaccine against challenge with 1 × 109 CFU Vibrio cholerae O139. In the present study, we investigated whether the vaccines can effectively protect immunized animals from any pathologic changes using histological, immunohistochemical and ultrastructural techniques. Severe pathology is evident in wild type injected ileum in non-immunized, showing extensive villous destruction, edema, necrosis and inflammation with infiltration of large numbers of inflammatory cells, extensive damage to the villi and microvilli with pore formation. Histology of ileum injected with wild type in immunized rabbit shows no significant pathological changes except for a few inflammatory cells in lamina propria with mild edema in mucosa and submucosa. immunohistochemical staining revealed O139 antigens of wild type are seen in the lamina propria of edematous villi, muscularis mucosa and submucosa with weak presence in the muscle coat in non-immunized rabbit after challenged with wild type in non-immunized rabbits, but in immunized rabbit localisation of the O139 LPS antigen is seen at the tips of the intact villi, within lamina propria and muscularis mucosa only. These observations suggest that the vaccine can effectively protect animals from any pathologic changes and eliminate V. cholerae O139 from the immunized animals.

Matched MeSH terms: Cholera/microbiology

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