MyMedR

Genetic variation among Malaysian isolates of Salmonella typhi as detected by ribosomal RNA gene restriction patterns

Pang T, Altwegg M, Martinetti G, Koh CL, Puthucheary S

Microbiol. Immunol., 1992;36(5):539-43.

Genetic variation among Malaysian isolates of Salmonella typhi was determined by analysis of ribosomal RNA gene restriction patterns. Of the 20 isolates analyzed, eight different pattern combinations were detected. The amount of variation observed was also dependent upon the restriction endonuclease used; PstI produced more different patterns than did SmaI. The results suggested that disease activity was due to a number of different clones circulating simultaneously rather than a single strain. Further implications of the data are discussed.

Matched MeSH terms: Salmonella typhi/genetics*

Genetic dynamics of Salmonella typhi--diversity in clonality

Pang T

Trends Microbiol., 1998 Sep;6(9):339-42.

PMID: 9778724

Matched MeSH terms: Salmonella typhi/genetics*; Salmonella typhi/pathogenicity

Typhoid fever--important issues still remain

Pang T, Levine MM, Ivanoff B, Wain J, Finlay BB

Trends Microbiol., 1998 Apr;6(4):131-3.

PMID: 9587187

Matched MeSH terms: Salmonella typhi/drug effects; Salmonella typhi/genetics

Report from an international symposium on typhoid fever

Pang T, Calva E, Punjabi N, Rowley D

Asian Pac J Allergy Immunol, 1992 Jun;10(1):73-7.

PMID: 1358084

Matched MeSH terms: Salmonella typhi/genetics; Salmonella typhi/immunology; Salmonella typhi/pathogenicity

Heat-killed Salmonella typhi induces the release of prostaglandins and leukotrienes from mouse macrophages

Pang T, Devi S, Puthucheary S, Pawlowski N

Microbiol. Immunol., 1991;35(3):267-71.

PMID: 1870442

Mouse macrophages pre-labeled with [3H]arachidonic acid (20:4) were shown to release metabolites generated by the lipoxygenase and cyclo-oxygenase pathways following in vitro addition of heat-killed Salmonella typhi. These metabolites were maximally released after 60-90 min of incubation and consisted of prostaglandins (85%), leukotriene C (6%), di-HETEs, leukotrienes D and E (4%), mono-HETEs (2%) and other metabolites (3%). Of the metabolites generated by the cyclo-oxygenase pathway (prostaglandins), 6-keto PGF1 alpha and PGE2 were generated at a ratio of 1.2 to 1. The significance and importance of these results are discussed.

Matched MeSH terms: Salmonella typhi/immunology*

False-positive widal test in nontyphoid Salmonella infections

Pang T, Pothocheary SD

Southeast Asian J. Trop. Med. Public Health, 1989 Mar;20(1):163-4.

PMID: 2672364

Matched MeSH terms: Salmonella typhi/isolation & purification; Salmonella typhimurium/isolation & purification

Significance and value of the Widal test in the diagnosis of typhoid fever in an endemic area

Pang T, Puthucheary SD

J Clin Pathol, 1983 Apr;36(4):471-5.

PMID: 6833514

The diagnostic value of the Widal test was assessed in an endemic area. The test was done on 300 normal individuals, 297 non-typhoidal fevers and 275 bacteriologically proven cases of typhoid. Of 300 normal individuals, 2% had an H agglutinin titre of 1/160 and 5% had an O agglutinin titre of 1/160. On the basis of these criteria a significant H and/or O agglutinin titre of 1/320 or more was observed in 93-97% of typhoid cases and in only 3% of patients with non-typhoidal fever. Of the sera from typhoid cases which gave a significant Widal reaction, the majority (79.9%) showed increases in both H and O agglutinins and 51 of 234 (21.8%) of these sera were collected in the first week of illness. The significance and implications of these findings are discussed.

Matched MeSH terms: Salmonella typhi/immunology; Salmonella typhi/isolation & purification

Immunogenic epitopes of Salmonella typhi GroEL heat shock protein reactive with both monoclonal antibody and patients sera

Panchanathan V, Naidu BR, Devi S, Di Pasquale A, Mason T, Pang T

Immunol Lett, 1998 Jun;62(2):105-9.

PMID: 9698106

A series of 122, 9-mer overlapping peptides based on the sequence of the Salmonella typhi GroEL gene was synthesized on the surfaces of polyethylene pins and screened with monoclonal antibody to GroEL and with human sera from patients with typhoid fever and normal healthy blood donors. Three immunogenic epitopes corresponding to peptides EGQDRGYSY, YSYNKETGE and GKGTEEKEK were identified upon screening with the human sera. In addition, screening of the peptides with a monoclonal antibody to GroEL detected binding to a third peptide, KGGKGTEEK, which contains a common overlapping sequence to peptide GKGTEEKEK. Identification and definition of these epitopes will be important in delineating the biological and immunological functions of this protein and in designing better diagnostic tests and vaccines.

Matched MeSH terms: Salmonella typhi/immunology*

Infections in post-tsunami victims

Othman N, Ismail IH, Yip R, Zainuddin Z, Kasim SM, Isa R, et al.

Pediatr Infect Dis J, 2007 Oct;26(10):960-1.

PMID: 17901807 DOI: 10.1097/INF.0b013e3181257234

Two tsunami survivors from Banda Acheh, Sumatra, presented with pyrexia of unknown origin and a nonresolving left-sided empyema, respectively. Both children had mixed infections of tuberculosis and melioidosis; Salmonella typhi was also present in the second patient. Mixed infections are common late sequela complications in post-tsunami victims.

Matched MeSH terms: Salmonella typhi/isolation & purification

Analysis and construction of pathogenicity island regulatory pathways in Salmonella enterica serovar Typhi

Ong SY, Ng FL, Badai SS, Yuryev A, Alam M

J Integr Bioinform, 2010;7(1).

PMID: 20861532 DOI: 10.2390/biecoll-jib-2010-145

Signal transduction through protein-protein interactions and protein modifications are the main mechanisms controlling many biological processes. Here we described the implementation of MedScan information extraction technology and Pathway Studio software (Ariadne Genomics Inc.) to create a Salmonella specific molecular interaction database. Using the database, we have constructed several signal transduction pathways in Salmonella enterica serovar Typhi which causes Typhoid Fever, a major health threat especially in developing countries. S. Typhi has several pathogenicity islands that control rapid switching between different phenotypes including adhesion and colonization, invasion, intracellular survival, proliferation, and biofilm formation in response to environmental changes. Understanding of the detailed mechanism for S. Typhi survival in host cells is necessary for development of efficient detection and treatment of this pathogen. The constructed pathways were validated using publically available gene expression microarray data for Salmonella.

Matched MeSH terms: Salmonella typhi/genetics*

Fulltext Complete genome sequence of Salmonella enterica subsp. enterica serovar Typhi P-stx-12

Ong SY, Pratap CB, Wan X, Hou S, Abdul Rahman AY, Saito JA, et al.

J Bacteriol, 2012 Apr;194(8):2115-6.

PMID: 22461552 DOI: 10.1128/JB.00121-12

We report here the complete genome sequence of Salmonella enterica subsp. enterica serovar Typhi P-stx-12, a clinical isolate obtained from a typhoid carrier in India.

Matched MeSH terms: Salmonella typhi/classification*; Salmonella typhi/genetics*

A simple adherence test for detection of IgM antibodies in typhoid

Ong LY, Pang T, Lim SH, Tan EL, Puthucheary SD

J Med Microbiol, 1989 Jul;29(3):195-8.

PMID: 2473209

A simple adherence test to detect IgM antibodies in patients with typhoid is described. The test utilises the IgM-"capture" approach, in which the test serum is applied to microtitration plate wells previously coated with anti-human IgM, followed by application of a stained Salmonella typhi antigen suspension which shows adherence in positive cases. By this test, 58 (95%) of 61 sera from confirmed cases of typhoid possessed IgM antibodies to the H or O or both antigens of S. typhi. In patients for whom a diagnosis of typhoid was based only on a significant Widal-test titre, 31 (41%) of 76 sera had IgM antibodies to the H or O or both antigens of S. typhi. Some cross-reactivity of the IgM antibodies was detected, especially with the O antigens of S. paratyphi A and B. A total of 82 sera from non-typhoidal fevers (leptospirosis, typhus, dengue fever) showed no reactivity in this test. In normal sera there was no detectable IgM to the O antigen of S. typhi and only a small number (3.9%) had low levels of IgM to the H antigen. The significance and potential importance of this simple, sensitive, specific and economical test is discussed.

Matched MeSH terms: Salmonella typhi/immunology*

Fulltext Multi-isotype antibody responses against the multimeric Salmonella Typhi recombinant hemolysin E antigen

Ong EB, Ignatius J, Anthony AA, Aziah I, Ismail A, Lim TS

Microbiol. Immunol., 2015 Jan;59(1):43-7.

PMID: 25399538 DOI: 10.1111/1348-0421.12211

The detection and measurement of different antibody isotypes in the serum provide valuable indicators of the different stages of typhoid infection. Here, the ability of S. Typhi recombinant hemolysin E (HlyE) to detect multi-isotype antibody responses in sera of patients with typhoid and paratyphoid A was investigated using an indirect antibody immunoassay. Nanogram amounts of HlyE were found to be sufficient for detection of IgG and IgA isotypes and, in a study of individuals' sera (n = 100), the immunoassay was able to distinguish between typhoid and non-typhoid sera. The overall sensitivity, specificity and efficiency of the ELISA were 70% (39/56), 100% (44/44) and 83% respectively.

Matched MeSH terms: Salmonella typhi/genetics; Salmonella typhi/immunology*

Cloning, expression, and purification of the hemolysin/cytolysin (HlyE antigen) from Salmonella enterica serovar Typhi: potential application for immunoassay development

Ong EB, Anthony AA, Ismail A, Ismail A, Lim TS

Diagn Microbiol Infect Dis, 2013 Sep;77(1):87-9.

PMID: 23790417 DOI: 10.1016/j.diagmicrobio.2013.05.010

The hemolysin (HlyE) protein of Salmonella enterica serovar Typhi was reported to be antigenic. This work describes the cloning, expression, and purification of a hexahistidine-tagged HlyE protein under native conditions. Immunoblot analysis and a competitive enzyme-linked immunosorbent assay using sera from typhoid patients showed the presence of HlyE-specific antibodies in circulation.

Matched MeSH terms: Salmonella typhi/genetics; Salmonella typhi/immunology*

Fulltext Detection of enterotoxin targeted entFM and hblA genes by inoculating Bacillus cereus (Strain BC1) into ready-to-eat food (RTF) and drink samples using polymerase chain reaction (PCR)

Nooratiny, I., Sahilah, A.M.

International Food Research Journal, 2013;20(4):1895-1899.

MyJurnal

Detection of enterotoxin by targeting entFM and hblA genes in Bacillus cereus BC1 strain inoculated into ready to eat food (RTF) and drink samples using polymerase chain reaction (PCR) was conducted. The B. cereus BC1 strain was confirmed as a Bacillus diarrhoeal enterotoxin (BDE) when tested by a commercially available Enzyme-linked immunosorbent assay-BDE immunoassay (ELISA-BDE immunoassay, TECRA). In the specificity study, both enterotoxin genes were detected on chromosomal DNA of B. cereus BC1 strain by showing a specific band of 1269 bp (entFM) and 874 bp (hblA), respectively. However, none of the target genes were detected for the other 15 genomic DNA bacteria (B. cereus (ATCC 11779), B. subtilis (ATCC 6633), Campylobacter jejuni (ATCC 29428), C. coli (Jabatan Kimia Malaysia, JKM), Clostridium perfringen (ATCC 13124), Enterobacter sakazaki (ATCC 51329), Escherichia coli (ATCC 43888), E. coli (ATCC 11735), Legionella pneumophila (ATCC 33152), Listeria monocytogenes (ATCC 35967), Salmonella typhi (IMR), S. enteritidis (ATCC 13076), S. typhimurium (ATCC 14028), Shigella flexeneri (ATCC 12022) and Vibrio cholerae bengal (Institute Medical Research (IMR), Malaysia) examined. The detection limit of both genes was 0.1 ng of genomic DNA. Thus, in the presence study it is evidence that the PCR analysis targeting enterotoxin of entFM and hblA genes are suitable and useful in detecting enterotoxic B. cereus in RTFs and drinks contaminated sample.

Matched MeSH terms: Salmonella typhi

Fulltext Non-protein coding RNA genes as the novel diagnostic markers for the discrimination of Salmonella species using PCR

Nithya R, Ahmed SA, Hoe CH, Gopinath SC, Citartan M, Chinni SV, et al.

PLoS One, 2015;10(3):e0118668.

PMID: 25774907 DOI: 10.1371/journal.pone.0118668

Salmonellosis, a communicable disease caused by members of the Salmonella species, transmitted to humans through contaminated food or water. It is of paramount importance, to generate accurate detection methods for discriminating the various Salmonella species that cause severe infection in humans, including S. Typhi and S. Paratyphi A. Here, we formulated a strategy of detection and differentiation of salmonellosis by a multiplex polymerase chain reaction assay using S. Typhi non-protein coding RNA (sRNA) genes. With the designed sequences that specifically detect sRNA genes from S. Typhi and S. Paratyphi A, a detection limit of up to 10 pg was achieved. Moreover, in a stool-seeding experiment with S. Typhi and S. Paratyphi A, we have attained a respective detection limit of 15 and 1.5 CFU/mL. The designed strategy using sRNA genes shown here is comparatively sensitive and specific, suitable for clinical diagnosis and disease surveillance, and sRNAs represent an excellent molecular target for infectious disease.

Matched MeSH terms: Salmonella typhi/genetics; Salmonella typhi/isolation & purification; Salmonella typhi/chemistry

Fulltext Parkinsonism and brain MRI findings in a relapsed culture-proven salmonella typhi infection: a case report in Malaysia

Ng, Y.M., Cheng, J.T.

JUMMEC, 2016;19(1):1-2.

MyJurnal

Typhoid fever is a systemic infection caused by Salmonella typhi, which may be associated with extra-intestinal
complications. Neurological manifestations, particularly Parkinsonism, are rarely reported. We report a
17-year-old patient with relapsed culture-proven Salmonella typhi infection who developed septic shock and
subsequently Parkinsonism. Lumbar puncture revealed acellular cerebrospinal fluid with raised protein level.
Magnetic resonance imaging revealed cerebral petechial haemorrhages resulted from small vessels vasculitis.
His symptoms resolved spontaneously after 3 months.

Matched MeSH terms: Salmonella typhi

Prevalence and antimicrobial resistance profile of Salmonella typhi infection in Iraq, 2019-2021

Nassir KF, Ali BM, Ibrahim ZH, Qasim ZJ, Mahdi SG, Mustafa NM, et al.

Med J Malaysia, 2024 Jan;79(1):74-79.

PMID: 38287761

INTRODUCTION: Salmonella typhi could infect the intestinal tract and the bloodstream or invade body organs and secrete endotoxins. It is endemic in developing countries. It is increasingly evolving antimicrobial resistance to several commonly used antimicrobial agents.

MATERIALS AND METHODS: A cross-sectional study was done at Iraqi Communicable Disease Control Center, where all confirmed cases of Salmonella typhi are reported, for a period 2019-2021. All demographic, epidemiological and clinical characteristics of patients, comorbidities, type of samples, distribution of S. typhi by age and gender, time distribution in each year and profile of bacterial resistance and sensitivity to antibiotics were gathered and analysed.

RESULTS: Most samples were taken from blood. The mean age of cases during 2019, 2020 and 2021 was 18.7 ± 6.5, 17.7 ± 14.1 and 17.3 ± 12.8. Males constituted 56.7%, 58.5% and 39.8%, respectively. Some cases had comorbidities. Most cases had headache and fever. Some of them had nausea, diarrhoea, vomiting and epigastric pain. The age and sex were significantly associated with years of reporting. The most months of case reporting were June-July (2019 and 2021), Jan. -Feb. (2020). There was an obvious increase in S. typhi resistance to ceftriaxone (92.2%, 86.1%, 88.8%) and ampicillin (77.1%, 76.9%, 81.27%). There was a gradual increase in sensitivity to tetracycline (83.1%, 88.1%, 94%), cotrimoxazole (86.7%, 86.1%, 92.2%), ciprofloxacin (78.3%, 90.1%, 87.8%) and cefixime (77.7%, 72.3%, 72.7%).

CONCLUSIONS: There was a sharp rise in resistance rates of the S. typhi in Iraq (during 2019-2021) to ceftriaxone and ampicillin, while there were highest sensitivity rates to imipenem, aztreonam and chloramphenicol. The following recommendations were made: (1) Improvement of general hygiene and food safety measures. (2) Emphasis on vaccination and surveillance of Salmonella infection. (3) Rational use of appropriate antibiotics through implementation of treatment guidelines. (5) Educate communities and travelers about the risks of S. typhi and its preventive measures.

Matched MeSH terms: Salmonella typhi

Genotypic characterization of Salmonella typhi by amplified fragment length polymorphism fingerprinting provides increased discrimination as compared to pulsed-field gel electrophoresis and ribotyping

Nair S, Schreiber E, Thong KL, Pang T, Altwegg M

J Microbiol Methods, 2000 Jun;41(1):35-43.

PMID: 10856775

Amplified fragment length polymorphism (AFLP) is a recently developed, PCR-based high resolution fingerprinting method that is able to generate complex banding patterns which can be used to delineate intraspecific genetic relationships among bacteria. In the present study, AFLP was evaluated for its usefulness in the molecular typing of Salmonella typhi in comparison to ribotyping and pulsed-field gel electrophoresis (PFGE). Six S. typhi isolates from diverse geographic areas (Malaysia, Indonesia, India, Chile, Papua New Guinea and Switzerland) gave unique, heterogeneous profiles when typed by AFLP, a result which was consistent with ribotyping and PFGE analysis. In a further study of selected S. typhi isolates from Papua New Guinea which caused fatal and non-fatal disease previously shown to be clonally related by PFGE, AFLP discriminated between these isolates but did not indicate a linkage between genotype with virulence. We conclude that AFLP (discriminatory index=0.88) has a higher discriminatory power for strain differentiation among S. typhi than ribotyping (DI=0.63) and PFGE (DI=0.74).

Matched MeSH terms: Salmonella typhi/classification*; Salmonella typhi/genetics

Convenient and versatile DNA extraction using agarose plugs for ribotyping of problematic bacterial species

Nair S, Karim R, Cardosa MJ, Ismail G, Pang T

J Microbiol Methods, 1999 Oct;38(1-2):63-7.

PMID: 10520586

We describe a convenient, versatile and safe method for preparing bacterial DNA for ribotyping analysis. In this method, extraction of bacterial DNA from Salmnonella typhi and Burkholderia pseudomallei. and subsequent restriction endonuclease digestion, was performed in agarose blocks/plugs thus minimizing shearing and loss of DNA, problems commonly associated with liquid phase phenol extraction. Digested DNA in the plugs was then electrophoresed directly, transferred to nylon membranes and hybridized with labeled rDNA probes in the usual manner to provide reproducible restriction patterns. This method is particularly useful for bacterial species where standard DNA extraction in the liquid phase using phenol has been problematic (e.g. B. pseudomallei) but can be used for any bacterial species. The DNA extracted within the agarose plugs can be stored for long periods and can be used in other, widely-used typing methods such as pulsed-field gel electrophoresis (PFGE) and PCR-based techniques. Embedding live cells directly in agarose plugs also minimizes the risk of exposure to these virulent human pathogens among laboratory workers.

Matched MeSH terms: Salmonella typhi/isolation & purification; Salmonella typhi/chemistry*

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