Displaying publications 81 - 100 of 127 in total

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  1. Importation and co-circulation of multiple serotypes of dengue virus in Sarawak, Malaysia
    Holmes EC, Tio PH, Perera D, Muhi J, Cardosa J
    Virus Res, 2009 Jul;143(1):1-5.
    PMID: 19463715 DOI: 10.1016/j.virusres.2009.02.020
    Although dengue is a common disease in South-East Asia, there is a marked absence of virological data from the Malaysian state of Sarawak located on the island of Borneo. From 1997 to 2002 we noted the co-circulation of DENV-2, DENV-3 and DENV-4 in Sarawak. To determine the origins of these Sarawak viruses we obtained the complete E gene sequences of 21 isolates. A phylogenetic analysis revealed multiple entries of DENV-2 and DENV-4 into Sarawak, such that multiple lineages co-circulate, yet with little exportation from Sarawak. Notably, all viral isolates were most closely related to those circulating in different localities in South-East Asia. In sum, our analysis reveals a frequent traffic of DENV in South-East Asia, with Sarawak representing a local sink population.
    Matched MeSH terms: Serotyping
  2. Molecular characterization of serogrouping and virulence genes of Malaysian Vibrio cholerae isolated from different sources
    Shuan Ju Teh C, Lin Thong K, Tein Ngoi S, Ahmad N, Balakrish Nair G, Ramamurthy T
    J Gen Appl Microbiol, 2009 Dec;55(6):419-25.
    PMID: 20118606
    A pair of primers targeting the hlyA gene for Vibrio cholerae which could distinguish the classical from El Tor biotypes was designed and combined with other specific primers for ompW, rfb complex, and virulence genes such as ctxA, toxR, and tcpI in a multiplex PCR (m-PCR) assay. This m-PCR correctly identified 39 V. cholerae from clinical, water and seafood samples. The efficiency of this multiplex PCR (m-PCR) was compared with conventional biochemical and serogrouping methods. One O139 and 25 O1 V. cholerae strains including 10 environmental strains harbored all virulence-associated genes except 1 clinical strain which only had toxR and hlyA genes. Thirteen environmental strains were classified as non-O1/non-O139 and had the toxR and hlyA genes only. The detection limit of m-PCR was 7 x 10(4) cfu/ml. The m-PCR test was reliable and rapid and reduced the identification time to 4 h.
    Matched MeSH terms: Serotyping
  3. Changes in serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates from adult patients in Asia: Emergence of drug-resistant non-vaccine serotypes
    Kim SH, Chung DR, Song JH, Baek JY, Thamlikitkul V, Wang H, et al.
    Vaccine, 2020 08 27;38(38):6065-6073.
    PMID: 31590932 DOI: 10.1016/j.vaccine.2019.09.065
    This study was performed to investigate the serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae in Asian countries. A prospective surveillance study on S. pneumoniae collected from adult patients (≥50 years old) with invasive pneumococcal disease or community-acquired pneumonia was performed at 66 hospitals in Asian countries (Korea, China, Malaysia, Singapore, the Philippines, and Thailand) in 2012-2017. Serotyping and antimicrobial susceptibility tests of 850 pneumococcal isolates were performed. The proportions of isolates with serotypes covered by 13-valent pneumococcal conjugate vaccine (PCV13) were 37.0% in Korea, 53.4% in China, 77.2% in Malaysia, 35.9% in the Philippines, 68.7% in Singapore, and 60.2% in Thailand. Major serotypes were 19F (10.4%), 19A (10.1%), and 3 (8.5%) in 2012-2017, with different serotype distributions in each country. Macrolide resistance in pneumococci was high (66.8%) and prevalence of multidrug resistance (MDR) also remained high (50.8%). MDR non-PCV13 serotypes such as 11A, 15A, 35B, and 23A have emerged in Asian countries. This study showed the persistent prevalence of 19F and 19A with a noteworthy increase of certain non-PCV13 serotypes in Asian countries. High prevalence of macrolide resistance and MDR was also found in pneumococcal isolates. These data emphasize the need for continued surveillance of pneumococcal epidemiology in Asia in the post-pneumococcal vaccine era.
    Matched MeSH terms: Serotyping
  4. Fulltext Characterization of multiple-antimicrobial-resistant Salmonella enterica Subsp. enterica isolated from indigenous vegetables and poultry in Malaysia
    Yoke-Kqueen C, Learn-Han L, Noorzaleha AS, Son R, Sabrina S, Jiun-Horng S, et al.
    Lett Appl Microbiol, 2008 Mar;46(3):318-24.
    PMID: 18179445 DOI: 10.1111/j.1472-765X.2007.02311.x
    The aims of this communication were to study characterization of serogroups among Salmonella isolates and the relationship of antimicrobial resistance to serogroups. Multiple antimicrobial resistance (MAR) was performed on 189 Salmonella enterica isolates associated with 38 different serovars that were recovered from poultry and four types of indigenous vegetables.
    Matched MeSH terms: Serotyping
  5. Fulltext Analysis of Salmonella enterica serovar Enteritidis isolates from chickens and chicken meat products in Malaysia using PFGE, and MLST
    Zakaria Z, Hassan L, Sharif Z, Ahmad N, Ali RM, Husin SA, et al.
    BMC Vet Res, 2020 Oct 17;16(1):393.
    PMID: 33069231 DOI: 10.1186/s12917-020-02605-y
    BACKGROUND: Salmonella is a very important foodborne pathogen causing illness in humans. The emergence of drug-resistant strains also constitutes a serious worry to global health and livestock productivity. This study investigated Salmonella isolates from chicken and chicken meat products using the phenotypic antimicrobial screening as well as the molecular characteristics of Salmonella isolates. Upon serotyping of the isolates, the antimicrobial susceptibility profiling using a panel of 9 commonly used antimicrobials was done. Subsequently, the molecular profiles of all the isolates were further determined using Pulsed Field Gel Electrophoresis (PFGE) and the Whole Genome Multi-Locus Sequence Type (wgMLST) analysis in order to obtain the sequence types.

    RESULTS: The PFGE data was input into FPQuest software, and the dendrogram generated was studied for possible genetic relatedness among the isolates. All the isolates were found to belong to the Salmonella Enteritidis serotype with notable resistance to tetracycline, gentamycin, streptomycin, and sulfadimidine. The S. Enteritidis isolates tested predominantly subtyped into the ST11 and ST1925, which was found to be a single cell variant of ST11. The STs were found to occur in chicken meats, foods, and live chicken cloacal swabs, which may indicate the persistence of the bacteria in multiple foci.

    CONCLUSION: The data demonstrate the presence of S. Enteritidis among chickens, indicating its preference and reservoir status for enteric Salmonella pathogens.

    Matched MeSH terms: Serotyping
  6. Simple and rapid detection of Salmonella strains by direct PCR amplification of the hilA gene
    Pathmanathan SG, Cardona-Castro N, Sánchez-Jiménez MM, Correa-Ochoa MM, Puthucheary SD, Thong KL
    J Med Microbiol, 2003 Sep;52(Pt 9):773-6.
    PMID: 12909653
    The suitability of a PCR procedure using a pair of primers targeting the hilA gene was evaluated as a means of detecting Salmonella species. A total of 33 Salmonella strains from 27 serovars and 15 non-Salmonella strains from eight different genera were included. PCR with all the Salmonella strains produced a 784 bp DNA fragment that was absent from all the non-Salmonella strains tested. The detection limit of the PCR was 100 pg with genomic DNA and 3 x 10(4) c.f.u. ml(-1) with serial dilutions of bacterial culture. An enrichment-PCR method was further developed to test the sensitivity of the hilA primers for the detection of Salmonella in faecal samples spiked with different concentrations of Salmonella choleraesuis subsp. choleraesuis serovar Typhimurium. The method described allowed the detection of Salmonella Typhimurium in faecal samples at a concentration of 3 x 10(2) c.f.u. ml(-1). In conclusion, the hilA primers are specific for Salmonella species and the PCR method presented may be suitable for the detection of Salmonella in faeces.
    Matched MeSH terms: Serotyping
  7. Fulltext Capsular serotyping of Pasteurella multocida from various animal hosts - a comparison of phenotypic and genotypic methods
    Arumugam ND, Ajam N, Blackall PJ, Asiah NM, Ramlan M, Maria J, et al.
    Trop Biomed, 2011 Apr;28(1):55-63.
    PMID: 21602769
    One hundred and fourteen strains of Pasteurella multocida were isolated from different domestic animals species (cattle, buffalo, sheep, goat, pig, rabbit, dog, cat), avian species (chicken, duck, turkey) and wild animals (deer, tiger, orang utan, marmoset). The serogroups of P. multocida were determined by both conventional capsular serotyping and a multiplex PCR assay targeting specific capsular genes. Based on the conventional serotyping method, the 114 strains of P. multocida were subtyped into 55 species-specific (untypeable strains) P. multocida, 15 serogroup A, 23 serogroup B and 21 serogroup D. Based on the multiplex PCR assay on the specific capsular genes associated with each serogroup, the 114 strains were further divided to 22 species-specific P. multocida (KMT1 - 460 bp), 53 serogroup A (A - 1,044 bp), 33 serogroup B (B - 760 bp) and 6 serogroup D (D - 657 bp). No serogroup E (511 bp) or F (851 bp) was detected among the Malaysian P. multocida. PCR-based typing was more discriminative and could further subtype the previously untypeable strains. Overall, there was a significant and positive correlation between both methods in serogrouping P. multocida (r = 0.7935; p<0.4893). Various serogroups of P. multocida were present among the livestock with 75% of the strains belonging to serogroups A or B. PCR serotyping was therefore a highly species-specific, sensitive and robust method for detection and differentiation of P. multocida serogroups compared to conventional serotyping. To the best of our knowledge, this is the first report from Malaysia of the application of a PCR to rapidly define the species-specific P. multocida and its serogroups as an important zoonotic pathogen in Malaysia.
    Matched MeSH terms: Serotyping
  8. Fulltext Non-O1, non-O139 Vibrio cholerae bacteraemia in splenectomised thalassaemic patient from Malaysia
    Deris ZZ, Leow VM, Wan Hassan WM, Nik Lah NA, Lee SY, Siti Hawa H, et al.
    Trop Biomed, 2009 Dec;26(3):320-5.
    PMID: 20237446
    Vibrio cholerae infection is mainly caused acute diarrhoea disease. Bacteraemia due to non-O1 V. cholerae is rare and mainly reported in liver cirrhotic patients. We report one case of non-O1 V. cholerae bacteraemia in splenectomised thalassaemic patient who presented with septic shock secondary to abdominal sepsis. She had undergone emergency laporatomy and was managed in the intensive care unit for nine days. She was treated with meropenem and doxycyline and discharged well after fourteen days of admission. The V. cholerae was identified by API 20NE, serotype and polymerase chain reaction showed as non-O1, non-O139 strain. Besides known cholera-like toxin and El Tor hemolysin, with increasing reported cases of V. cholerae bacteraemia, there is possibility of other virulence factors that allow this organism to invade the bloodstream.
    Matched MeSH terms: Serotyping
  9. Fulltext Molecular characterization of Malaysian fowl adenovirus (FAdV) serotype 8b species E and pathogenicity of the virus in specific-pathogen-free chicken
    Sabarudin NS, Tan SW, Phang YF, Omar AR
    J Vet Sci, 2021 Jul;22(4):e42.
    PMID: 34313038 DOI: 10.4142/jvs.2021.22.e42
    BACKGROUND: Inclusion body hepatitis (IBH) is an economically important viral disease primarily affecting broiler and breeder chickens. All 12 serotypes of fowl adenovirus (FAdV) can cause IBH.

    OBJECTIVES: To characterize FAdV isolates based on phylogenetic analysis, and to study the pathogenicity of FAdV-8b in specific-pathogen-free (SPF) chickens following virus inoculation via oral and intramuscular (IM) routes.

    METHODS: Suspected organ samples were subjected to virus isolation and polymerase chain reaction (PCR) for FAdV detection. Hexon gene sequencing and phylogenetic analysis were performed on FAdV-positive samples for serotype identification. One FAdV-8b isolate, UPM/FAdV/420/2017, was selected for fiber gene characterization and pathogenicity study and was inoculated in SPF chickens via oral and IM routes.

    RESULTS: The hexon gene phylogenetic analysis revealed that all isolates belonged to FAdV-8b. The fiber gene-based phylogenetic analysis of isolate UPM/FAdV/420/2017 supported the grouping of that isolate into FAdV species E. Pathogenicity study revealed that, chickens infected with UPM/FAdV/420/2017 via the IM route had higher clinical score values, higher percent mortality, higher degree of the liver lesions, higher antibody response (p < 0.05), and higher virus shedding amounts (p < 0.05) than those infected via the oral route. The highest virus copy numbers were detected in liver and gizzard.

    CONCLUSIONS: FAdV-8b is the dominant FAdV serotype in Malaysia, and pathogenicity study of the FAdV-8b isolate UPM/FAdV/420/2017 indicated its ability to induce IBH in young SPF chickens when infected via oral or IM routes.

    Matched MeSH terms: Serotyping
  10. Protection against scrub typhus infection engendered by the passive transfer of immune sera
    Robinson DM, Huxsoll DL
    Southeast Asian J. Trop. Med. Public Health, 1975 Dec;6(4):477-82.
    PMID: 818716
    The passive transfer of convalescent sera did not protect the majority of mice against challenge with the homologous strain and was completely ineffective against challenge with strains unrelated by fluorescent antibody techniques. When the immune sera was incubated with the rickettsia in vitro and then inoculated into the mice a dramatic increase occurred in the number of surviving mice. The importance of these data in relation to published results with other species of rickettsia is discussed.
    Matched MeSH terms: Serotyping
  11. Rickettsia tsutsugamushi infections in chiggers and small mammals on a mature oil palm estate
    Shirai A, Robinson DM, Lim BL, Dohany AL, Huxsoll DL
    Southeast Asian J. Trop. Med. Public Health, 1978 Sep;9(3):356-60.
    PMID: 107596
    An epidemiological study in a mature oil palm estate in Peninsular Malaysia has demonstrated a low prevalence of R. tsutsugamushi infection in small mammals. The direct fluorescent antibody technique for assaying infections in chiggers proved more sensitive than mouse inoculation. Most infections in both chiggers and rodents were caused by the Karp strain.
    Matched MeSH terms: Serotyping
  12. Fulltext Clinical predictors of dengue fever co-infected with leptospirosis among patients admitted for dengue fever - a pilot study
    Suppiah J, Chan SY, Ng MW, Khaw YS, Ching SM, Mat-Nor LA, et al.
    J Biomed Sci, 2017 Jun 28;24(1):40.
    PMID: 28659189 DOI: 10.1186/s12929-017-0344-x
    BACKGROUND: Dengue and leptospirosis infections are currently two major endemics in Malaysia. Owing to the overlapping clinical symptoms between both the diseases, frequent misdiagnosis and confusion of treatment occurs. As a solution, the present work initiated a pilot study to investigate the incidence related to co-infection of leptospirosis among dengue patients. This enables the identification of more parameters to predict the occurrence of co-infection.

    METHOD: Two hundred sixty eight serum specimens collected from patients that were diagnosed for dengue fever were confirmed for dengue virus serotyping by real-time polymerase chain reaction. Clinical, laboratory and demographic data were extracted from the hospital database to identify patients with confirmed leptospirosis infection among the dengue patients. Thus, frequency of co-infection was calculated and association of the dataset with dengue-leptospirosis co-infection was statistically determined.

    RESULTS: The frequency of dengue co-infection with leptospirosis was 4.1%. Male has higher preponderance of developing the co-infection and end result of shock as clinical symptom is more likely present among co-infected cases. It is also noteworthy that, DENV 1 is the common dengue serotype among all cases identified as dengue-leptospirosis co-infection in this study.

    CONCLUSION: The increasing incidence of leptospirosis among dengue infected patients has posed the need to precisely identify the presence of co-infection for the betterment of treatment without mistakenly ruling out either one of them. Thus, anticipating the possible clinical symptoms and laboratory results of dengue-leptospirosis co-infection is essential.

    Matched MeSH terms: Serotyping
  13. Fulltext Emergence of Genotype I of Dengue Virus Serotype 3 during a Severe Dengue Epidemic in Sri Lanka in 2017
    Ngwe Tun MM, Muthugala R, Rajamanthri L, Nabeshima T, Buerano CC, Morita K
    Jpn J Infect Dis, 2021 Sep 22;74(5):443-449.
    PMID: 33642435 DOI: 10.7883/yoken.JJID.2020.854
    During the 2017 outbreak of severe dengue in Sri Lanka, dengue virus (DENV) serotypes 2, 3, and 4 were found to be co-circulating. Our previous study of 295 patients from the National Hospital Kandy in Sri Lanka between March 2017 and January 2018 determined that the dominant infecting serotype was DENV-2. In this study, we aimed to characterize the DENV-3 strains from non-severe and severe dengue patients from our previous study population. Patients' clinical records and previous laboratory tests, including dengue-specific nonstructural protein 1 antigen rapid test and IgM-capture and IgG enzyme-linked immunosorbent assays, were analyzed together with the present results of real-time reverse transcription polymerase chain reaction and next-generation sequencing of DENV-3. Complete genome analysis determined that DENV-3 isolates belonged to 2 different clades of genotype I and were genetically close to strains from Indonesia, China, Singapore, Malaysia, and Australia. There were 16 amino acid changes among DENV-3 isolates, and a greater number of changes were found in nonstructural proteins than in structural proteins. The emergence of DENV-3 genotype I was noted for the first time in Sri Lanka. Continuous monitoring of this newly emerged genotype and other DENV serotypes and genotypes is needed to determine their effects on future outbreaks and understand the molecular epidemiology of dengue.
    Matched MeSH terms: Serotyping
  14. Fulltext Reduced fluoroquinolone susceptibility in Salmonella enterica isolates from travelers, Finland
    Lindgren MM, Kotilainen P, Huovinen P, Hurme S, Lukinmaa S, Webber MA, et al.
    Emerg Infect Dis, 2009 May;15(5):809-12.
    PMID: 19402977 DOI: 10.3201/eid1505.080849
    We tested the fluoroquinolone susceptibility of 499 Salmonella enterica isolates collected from travelers returning to Finland during 2003-2007. Among isolates from travelers to Thailand and Malaysia, reduced fluoroquinolone susceptibility decreased from 65% to 22% (p = 0.002). All isolates showing nonclassical quinolone resistance were from travelers to these 2 countries.
    Matched MeSH terms: Serotyping
  15. Fulltext Augmented inflammatory cytokines in primary dengue infection progressing to shock
    Iyngkaran N, Yadav M, Sinniah M
    Singapore Med J, 1995 Apr;36(2):218-21.
    PMID: 7676273
    Dengue fever (DF) which is caused by four serotypes of dengue virus may in some cases progress into a life threatening situation of dengue haemorrhage fever (DHF) and dengue shock syndrome (DSS). It has been suggested that sequential infection with different dengue virus serotypes predisposes the patient towards DHF/DSS. We report here a primary dengue infection in a 10-year-old boy progressing from DF to DSS while under clinical observation. The report provides unequivocal evidence for the development of DSS in primary dengue infection caused by virus serotype 4. The close relationship between sequential changes in the levels of tumour necrosis factor (TNF), Interleukin 1 and 6 (IL-1 and IL-6) in the serum, to the clinical progression of the disease from DF to DHF/DSS and then to full recovery implicates a pathogenetic role for the inflammatory cytokines. The child also manifested clinical features consistent with Reye's syndrome and this suggests a common pathogenetic origin for DSS and the Reye-like syndrome induced by dengue virus.
    Matched MeSH terms: Serotyping
  16. Pathogenic and saprophytic Leptospira species in water and soils from selected urban sites in peninsular Malaysia
    Benacer D, Woh PY, Mohd Zain SN, Amran F, Thong KL
    Microbes Environ, 2013;28(1):135-40.
    PMID: 23363618
    Leptospira species were studied in water and soils from selected urban sites in Malaysia. A total of 151 water (n=121) and soil (n=30) samples were collected from 12 recreational lakes and wet markets. All samples were filtered and inoculated into semi-solid Ellinghausen and McCullough modified by Johnson and Harris (EMJH) media supplemented with additional 5-fluorouracil. The cultures were then incubated at 30°C and observed under a dark field microscope with intervals of 10 days. A PCR assay targeting the rrs gene was used to confirm the genus Leptospira among the isolates. Subsequently, the pathogenic status of the isolates was determined using primer sets G1/G2 and Sapro1/Sapro2, which target the secY and rrs genes, respectively. The isolates were identified at serogroup level using the microscopic agglutination test (MAT) while their genetic diversity was assessed by pulsed field gel electrophoresis (PFGE). Based on dark field microscopy, 23.1% (28/121) water and 23.3% (7/30) soil cultures were positive for Leptospira spp. Of the 35 positive cultures, only 8 were pure and confirmed as Leptospira genus by PCR assay. Two out of 8 isolates were confirmed as pathogenic, 5 were saprophytic and one was intermediate. These 8 isolates were negative for the 25 reference hyperimmune rabbit sera tested in the MAT. PFGE showed that all 8 of these environmental Leptospira spp. were genetically diverse. In conclusion, the presence of pathogenic Leptospira spp. in the urban Malaysian environment may indicate and highlight the importance of water screening, especially in recreational lakes, in order to minimize any chance of Leptospira infection.
    Matched MeSH terms: Serotyping
  17. Genetic diversity of clinical and environmental strains of Salmonella enterica serotype Weltevreden isolated in Malaysia
    Thong KL, Goh YL, Radu S, Noorzaleha S, Yasin R, Koh YT, et al.
    J Clin Microbiol, 2002 Jul;40(7):2498-503.
    PMID: 12089269
    The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.
    Matched MeSH terms: Serotyping
  18. Fulltext The role of interspecies recombination in the evolution of antibiotic-resistant pneumococci
    D'Aeth JC, van der Linden MP, McGee L, de Lencastre H, Turner P, Song JH, et al.
    Elife, 2021 Jul 14;10.
    PMID: 34259624 DOI: 10.7554/eLife.67113
    Multidrug-resistant Streptococcus pneumoniae emerge through the modification of core genome loci by interspecies homologous recombinations, and acquisition of gene cassettes. Both occurred in the otherwise contrasting histories of the antibiotic-resistant S. pneumoniae lineages PMEN3 and PMEN9. A single PMEN3 clade spread globally, evading vaccine-induced immunity through frequent serotype switching, whereas locally circulating PMEN9 clades independently gained resistance. Both lineages repeatedly integrated Tn916-type and Tn1207.1-type elements, conferring tetracycline and macrolide resistance, respectively, through homologous recombination importing sequences originating in other species. A species-wide dataset found over 100 instances of such interspecific acquisitions of resistance cassettes and flanking homologous arms. Phylodynamic analysis of the most commonly sampled Tn1207.1-type insertion in PMEN9, originating from a commensal and disrupting a competence gene, suggested its expansion across Germany was driven by a high ratio of macrolide-to-β-lactam consumption. Hence, selection from antibiotic consumption was sufficient for these atypically large recombinations to overcome species boundaries across the pneumococcal chromosome.
    Matched MeSH terms: Serotyping
  19. Fulltext Prevalence and characterization of verotoxigenic-Escherichia coli isolates from pigs in Malaysia
    Ho WS, Tan LK, Ooi PT, Yeo CC, Thong KL
    BMC Vet Res, 2013;9:109.
    PMID: 23731465 DOI: 10.1186/1746-6148-9-109
    Postweaning diarrhea caused by pathogenic Escherichia coli, in particular verotoxigenic E. coli (VTEC), has caused significant economic losses in the pig farming industry worldwide. However, there is limited information on VTEC in Malaysia. The objective of this study was to characterize pathogenic E. coli isolated from post-weaning piglets and growers with respect to their antibiograms, carriage of extended-spectrum beta-lactamases, pathotypes, production of hemolysins and fimbrial adhesins, serotypes, and genotypes.
    Matched MeSH terms: Serotyping
  20. Fulltext The discrimination of d-tartrate positive and d-tartrate negative S. enterica subsp. enterica serovar Paratyphi B isolated in Malaysia by phenotypic and genotypic methods
    Ahmad N, Hoon ST, Ghani MK, Tee KY
    Malays J Pathol, 2012 Jun;34(1):35-9.
    PMID: 22870596 MyJurnal
    Serotyping is not sufficient to differentiate between Salmonella species that cause paratyphoid fever from the strains that cause milder gastroenteritis as these organisms share the same serotype Salmonella Paratyphi B (S. Paratyphi B). Strains causing paratyphoid fever do not ferment d-tartrate and this key feature was used in this study to determine the prevalence of these strains among the collection of S. Paratyphi B strains isolated from patients in Malaysia. A total of 105 isolates of S. Paratyphi B were discriminated into d-tartrate positive (dT+) and d-tartrate negative (dT) variants by two lead acetate test protocols and multiplex PCR. The lead acetate test protocol 1 differed from protocol 2 by a lower inoculum size and different incubation conditions while the multiplex PCR utilized 2 sets of primers targeting the ATG start codon of the gene STM3356. Lead acetate protocol 1 discriminated 97.1% of the isolates as S. Paratyphi B dT+ and 2.9% as dT while test protocol 2 discriminated all the isolates as S. Paratyphi B dT+. The multiplex PCR test identified all 105 isolates as S. Paratyphi B dT+ strains. The concordance of the lead acetate test relative to that of multiplex PCR was 97.7% and 100% for protocol 1 and 2 respectively. This study showed that S. Paratyphi B dT+ is a common causative agent of gastroenteritis in Malaysia while paratyphoid fever appears to be relatively uncommon. Multiplex PCR was shown to be a simpler, more rapid and reliable method to discriminate S. Paratyphi B than the phenotypic lead acetate test.
    Matched MeSH terms: Serotyping
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