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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: Bacterial Typing Techniques*
Fulltext Molecular characterization of Streptococcus agalactiae strains isolated from fishes in Malaysia

Amal MN, Zamri-Saad M, Siti-Zahrah A, Zulkafli AR, Nur-Nazifah M

J Appl Microbiol, 2013 Jul;115(1):20-9.
PMID: 23557382 DOI: 10.1111/jam.12210

AIMS: The aim of this study was to characterize Streptococcus agalactiae strains that were isolated from fishes in Malaysia using random amplified polymorphic DNA (RAPD) and repetitive extragenic palindromic PCR (REP-PCR) techniques.
METHODS AND RESULTS: A total of 181 strains of Strep. agalactiae isolated from red hybrid tilapia (Oreochromis sp.) and golden pompano (Trachinotus blochii) were characterized using RAPD and REP-PCR techniques. Both the fingerprinting techniques generated reproducible band patterns, differing in the number and molecular mass amplicons. The RAPD technique displayed greater discriminatory power by its production of more complex binding pattern and divided all the strains into 13 groups, compared to 9 by REP-PCR technique. Both techniques showed the availability to differentiate the genetic profiles of the strains according to their geographical location of origin. Three strains of Strep. agalactiae that were recovered from golden pompano showed a genetic dissimilarity from the strains isolated from red hybrid tilapia, while the strain of ATCC 27956 that recovered from bovine displayed a unique profile for both methods.
CONCLUSIONS: Both techniques possess excellent discriminative capabilities and can be used as a rapid means of comparing Strep. agalactiae strains for future epidemiological investigation.
SIGNIFICANCE AND IMPACT OF THE STUDY: Framework as the guideline in traceability of this disease and in the search for potential local vaccine candidates for streptococcosis in this country.

Matched MeSH terms: Bacterial Typing Techniques/methods
Application of real-time polymerase chain reaction in detection of Entamoeba histolytica in pus aspirates of liver abscess patients

Othman N, Mohamed Z, Verweij JJ, Huat LB, Olivos-García A, Yeng C, et al.

Foodborne Pathog Dis, 2010 Jun;7(6):637-41.
PMID: 20132028 DOI: 10.1089/fpd.2009.0427

Entamoeba histolytica is the second major cause of liver abscess disease in humans, particularly in developing countries. Recently, DNA molecular-based methods have been employed to enhance the detection of E. histolytica in either pus or stool specimens. In this study, the results of real-time polymerase chain reaction (PCR) to detect E. histolytica DNA in pus from liver abscess cases were compared with those of indirect hemagglutination assay on the corresponding serum samples. Bacterial cultures were also performed on the pus samples for the diagnosis of pyogenic liver abscess. The real-time PCR detected E. histolytica DNA in 23 of 30 (76.7%) pus samples, when compared with 14 of 30 (46.7%) serum samples in which anti-Entamoeba antibodies were detected by indirect hemagglutination assay and 4 of 30 (13.3%) pus samples that showed bacterial infection by culture. The use of real-time PCR is a promising detection method for diagnosis and epidemiology assessment of amoebic liver abscess.

Matched MeSH terms: Bacterial Typing Techniques
Detection of Escherichia coli O157:H7 by multiplex PCR and their characterization by plasmid profiling, antimicrobial resistance, RAPD and PFGE analyses

Radu S, Ling OW, Rusul G, Karim MI, Nishibuchi M

J Microbiol Methods, 2001 Aug;46(2):131-9.
PMID: 11412923

Twenty-five and three strains of Escherichia coli O157:H7 were identified from 25 tenderloin beef and three chicken meat burger samples, respectively. The bacteria were recovered using the immunomagnetic separation procedure followed by selective plating on sorbitol MacConkey agar and were identified as E. coli serotype O157:H7 with three primer pairs that amplified fragments of the SLT-I, SLT-II and H7 genes in PCR assays. Susceptibility testing to 14 antibiotics showed that all were resistant to two or more antibiotics tested. Although all 28 strains contained plasmid, there was very little variation in the plasmid sizes observed. The most common plasmid of 60 MDa was detected in all strains. We used DNA fingerprinting by randomly amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) to compare the 28 E. coli O157:H7 strains. At a similarity level of 90%, the results of PFGE after restriction with XbaI separated the E. coli O157:H7 strains into 28 single isolates, whereas RAPD using a single 10-mer oligonucleotides separated the E. coli O157:H7 strains into two clusters and 22 single isolates. These typing methods should aid in the epidemiological clarification of the E. coli O157:H7 in the study area.

Matched MeSH terms: Bacterial Typing Techniques
Phenotypic and genotypic characteristics and epidemiological significance of ctx+ strains of Vibrio cholerae isolated from seafood in Malaysia

Chen CH, Shimada T, Elhadi N, Radu S, Nishibuchi M

Appl Environ Microbiol, 2004 Apr;70(4):1964-72.
PMID: 15066786

Of 97 strains of Vibrio cholerae isolated from various seafoods in Malaysia in 1998 and 1999, 20 strains carried the ctx gene and produced cholera toxin. Fourteen, one, and five of these toxigenic strains belonged to the O139, O1 Ogawa, and rough serotypes, respectively. The rough strains had the rfb gene of the O1 serotype. The toxigenic strains varied in their biochemical characteristics, the amount of cholera toxin produced, their antibiograms, and the presence or absence of the pTLC plasmid sequence. DNA fingerprinting analysis by arbitrarily primed PCR, ribotyping, and a pulsed-field gel electrophoresis method classified the toxigenic strains into 3, 7, and 10 types, respectively. The relatedness of these toxigenic strains to clinical strains isolated in other countries and from international travelers was examined by using a dendrogram constructed from the pulsed-field gel electrophoresis profiles. The results of the examination of the antibiogram and the possession of the toxin-linked cryptic plasmid were consistent with the dendrogram-based relatedness: the O139 strains isolated from Malaysian seafoods could be separated into two groups that appear to have been introduced from the Bengal area independently. The rough strains of Malaysian seafood origin formed one group and belonged to a cluster unique to the Thailand-Malaysia-Laos region, and this group may have persisted in this area for a long period. The single O1 Ogawa strain detected in Malaysian seafood appears to have an origin and route of introduction different from those of the O139 and the rough strains.

Matched MeSH terms: Bacterial Typing Techniques
A single-gene approach for the subspecies classification of Mycobacteroides abscessus

Ng HF, Ngeow YF

Pathog Dis, 2020 11 11;78(8).
PMID: 32945880 DOI: 10.1093/femspd/ftaa055

The subspecies classification of Mycobacteroides abscessus complex into M. abscessus, M. massiliense and M. bolletii requires the amplification and sequencing of multiple genes. The objective of this study was to evaluate the possibility of subspecies classification using a single PCR target. An in silico study was performed to classify 1613 strains deposited in a public database using 9 genes (partial gene sequences of hsp65, rpoB, sodA, argH, cya, glpK, gnd, and murC, and the full gene sequence of MAB_3542c). We found the housekeeping gene gnd to be able to classify the M. abscessus subspecies with high accuracy (99.94%). A single-gene PCR approach based on gnd would be a suitable replacement for the more expensive, labor-intensive and time-consuming multi-gene PCR analysis currently in use for the subspecies identification of M. abscessus.

Matched MeSH terms: Bacterial Typing Techniques/methods*
Fulltext Annotated genome sequence of Mycobacterium massiliense strain M154, belonging to the recently created taxon Mycobacterium abscessus subsp. bolletii comb. nov

Choo SW, Wong YL, Tan JL, Ong CS, Wong GJ, Ng KP, et al.

J Bacteriol, 2012 Sep;194(17):4778.
PMID: 22887675 DOI: 10.1128/JB.01043-12

Mycobacterium massiliense has recently been proposed as a member of Mycobacterium abscessus subsp. bolletii comb. nov. Strain M154, a clinical isolate from the bronchoalveolar lavage fluid of a Malaysian patient presenting with lower respiratory tract infection, was subjected to shotgun DNA sequencing with the Illumina sequencing technology to obtain whole-genome sequence data for comparison with other genetically related strains within the M. abscessus species complex.

Matched MeSH terms: Bacterial Typing Techniques
mec-associated dru typing in the epidemiological analysis of ST239 MRSA in Malaysia

Ghaznavi-Rad E, Goering RV, Nor Shamsudin M, Weng PL, Sekawi Z, Tavakol M, et al.

Eur J Clin Microbiol Infect Dis, 2011 Nov;30(11):1365-9.
PMID: 21479532 DOI: 10.1007/s10096-011-1230-1

The usefulness of mec-associated dru typing in the epidemiological analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolated in Malaysia was investigated and compared with pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and spa and SCCmec typing. The isolates studied included all MRSA types in Malaysia. Multilocus sequence type ST188 and ST1 isolates were highly clonal by all typing methods. However, the dru typing of ST239 isolates produced the clearest discrimination between SCCmec IIIa and III isolates, yielding more subtypes than any other method. Evaluation of the discriminatory power for each method identified dru typing and PFGE as the most discriminatory, with Simpson's index of diversity (SID) values over 89%, including an isolate which was non-typeable by spa, but dru-typed as dt13j. The discriminatory ability of dru typing, especially with closely related MRSA ST239 strains (e.g., Brazilian and Hungarian), underscores its utility as a tool for the epidemiological investigation of MRSA.

Matched MeSH terms: Bacterial Typing Techniques/methods*
Methicillin-susceptible Staphylococcus aureus from clinical and community sources are genetically diverse

Ghasemzadeh-Moghaddam H, Ghaznavi-Rad E, Sekawi Z, Yun-Khoon L, Aziz MN, Hamat RA, et al.

Int J Med Microbiol, 2011 Apr;301(4):347-53.
PMID: 21193348 DOI: 10.1016/j.ijmm.2010.10.004

Despite the association of methicillin-susceptible S. aureus (MSSA) with several life-threatening diseases, relatively little is known about their clinical epidemiology in Malaysia. We characterized MSSA isolates (n=252) obtained from clinical and community (carriage) sources based on spa sequencing and multilocus sequence typing (MLST). The prevalence of several important virulence genes was determined to further define the molecular characteristics of MSSA clones circulating in Malaysia. Among the 142 clinical and 110 community-acquired MSSA isolates, 98 different spa types were identified, corresponding to 8 different spa clonal clusters (spa-CCs). In addition, MLST analysis revealed 22 sequence types (STs) with 5 singletons corresponding to 12 MLST-CCs. Interestingly, spa-CC084/085 (MLST-CC15) (p=0.038), spa-non-founder 2 (MLST-ST188) (p=0.002), and spa-CC127 (MLST-CC1) (p=0.049) were identified significantly more often among clinical isolates. spa-CC3204 (MLST-CC121) (p=0.02) and spa-CC015 (MLST-CC45) (p=0.0002) were more common among community isolates. Five dominant MLST-CCs (CC8, CC121, CC1, CC45, and CC5) having clear counterparts among the major MRSA clones were also identified in this study. While the MSSA strains are usually genetically heterogeneous, a relatively high frequency (19/7.5%) of ST188 (t189) strains was found, with 57.8% of these strains carrying the Panton-Valentine leukocidin (PVL). Analysis of additional virulence genes showed a frequency of 36.5% and 36.9% for seg and sei and 0.8% and 6.3% for etb and tst genes, respectively. Arginine catabolic mobile element (ACME) was detected in 4 community isolates only. These represent the first isolates harbouring this gene in an Asian region. In conclusion, MSSA from the Malaysian community and their clinical counterparts are genetically diverse, but certain clones occur more often among clinical isolates than among carriage isolates and vice versa.

Matched MeSH terms: Bacterial Typing Techniques
A simplified multiplex PCR assay for fast and easy discrimination of globally distributed staphylococcal cassette chromosome mec types in meticillin-resistant Staphylococcus aureus

Ghaznavi-Rad E, Nor Shamsudin M, Sekawi Z, van Belkum A, Neela V

J Med Microbiol, 2010 Oct;59(Pt 10):1135-1139.
PMID: 20616192 DOI: 10.1099/jmm.0.021956-0

A multiplex PCR assay was developed for the identification of major types and subtypes of staphylococcal cassette chromosome mec (SCCmec) in meticillin-resistant Staphylococcus aureus (MRSA) strains. The method uses a novel 9 valent multiplex PCR plus two primer pairs for S. aureus identification and detection of meticillin resistance. All 389 clinical MRSA isolates from Malaysia and 18 European isolates from the Harmony collection harbouring different SCCmec types that we tested were correctly characterized by our PCR assay. SCCmec type III and V were by far the most common types among both hospital- and community-acquired Malaysian MRSA isolates, with an apparent emergence of MRSA harbouring the IVh type.

Matched MeSH terms: Bacterial Typing Techniques*
Fulltext Predominance and emergence of clones of hospital-acquired methicillin-resistant Staphylococcus aureus in Malaysia

Ghaznavi-Rad E, Nor Shamsudin M, Sekawi Z, Khoon LY, Aziz MN, Hamat RA, et al.

J Clin Microbiol, 2010 Mar;48(3):867-72.
PMID: 20089756 DOI: 10.1128/JCM.01112-09

We define the epidemiology of predominant and sporadic methicillin-resistant Staphylococcus aureus (MRSA) strains in a central teaching and referral hospital in Kuala Lumpur, Malaysia. This is done on the basis of spa sequencing, multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, and virulence gene profiling. During the period of study, the MRSA prevalence was 44.1%, and 389 MRSA strains were included. The prevalence of MRSA was found to be significantly higher in the patients of Indian ethnicity (P < 0.001). The majority (92.5%) of the isolates belonged to ST-239, spa type t037, and possessed the type III or IIIA SCCmec. The arginine catabolic mobile element (ACME) arcA gene was detected in three (1.05%) ST-239 isolates. We report the first identification of ACME arcA gene-positive ST-239. Apart from this predominant clone, six (1.5%) isolates of ST-22, with two related spa types (t032 and t4184) and a singleton (t3213), carrying type IVh SCCmec, were detected for the first time in Asia. A limited number of community-acquired (CA) MRSA strains were also detected. These included ST-188/t189 (2.1%), ST-1/t127 (2.3%), and ST-7/t091 (1%). Panton-Valentin leukocidin (PVL) was detected in all ST-1 and ST-188 strains and in 0.7% of the ST-239 isolates. The majority of the isolates carried agr I, except that ST-1 strains were agr III positive. Virulence genes seg and sei were seen only among ST-22 isolates. In conclusion, current results revealed the predominance of ST-239-SCCmec III/IIIA and the penetration of ST-22 with different virulence gene profiles. The emergence in Malaysia of novel clones of known epidemic and pathogenic potential should be taken seriously.

Matched MeSH terms: Bacterial Typing Techniques*
[A genetically isolated population of Saccharomyces cerevisiae in Malaysia]

Naumov GI, Serpova EV, Naumova ES

Mikrobiologiia, 2006 Mar-Apr;75(2):245-9.
PMID: 16758873

A divergent population of Saccharomyces cerevisiae has been identified in Malaysia by molecular and genetic analysis. It has also demonstrated that the yeast S. bayanus may be found in South America. Problems of the origin of S. cerevisiae are discussed.

Matched MeSH terms: Bacterial Typing Techniques
Fulltext Multi locus sequence typing of clinical Burkholderia pseudomallei isolates from Malaysia

Arushothy R, Amran F, Samsuddin N, Ahmad N, Nathan S

PLoS Negl Trop Dis, 2020 12;14(12):e0008979.
PMID: 33370273 DOI: 10.1371/journal.pntd.0008979

BACKGROUND: Melioidosis is a neglected tropical disease with rising global public health and clinical importance. Melioidosis is endemic in Southeast Asia and Northern Australia and is of increasing concern in Malaysia. Despite a number of reported studies from Malaysia, these reports are limited to certain parts of the country and do not provide a cohesive link between epidemiology of melioidosis cases and the nation-wide distribution of the causative agent Burkholderia pseudomallei.
METHODOLOGY/PRINCIPLE FINDINGS: Here we report on the distribution of B. pseudomallei sequence types (STs) in Malaysia and how the STs are related to STs globally. We obtained 84 culture-confirmed B. pseudomallei from confirmed septicaemic melioidosis patients from all over Malaysia. Prior to performing Multi Locus Sequence Typing, the isolates were subjected to antimicrobial susceptibility testing and detection of the YLF/BTFC genes and BimA allele. Up to 90.5% of the isolates were sensitive to all antimicrobials tested while resistance was observed for antimicrobials typically administered during the eradication stage of treatment. YLF gene cluster and bimABp allele variant were detected in all the isolates. The epidemiological distribution patterns of the Malaysian B. pseudomallei isolates were analysed in silico using phylogenetic tools and compared to Southeast Asian and world-wide isolates. Genotyping of the 84 Malaysian B. pseudomallei isolates revealed 29 different STs of which 6 (7.1%) were novel. ST50 was identified as the group founder followed by subgroup founders ST376, ST211 and ST84. A low-level diversity is noted for the B. pseudomallei isolates described in this study while phylogenetic analysis associated the Malaysian STs to Southeast Asian isolates especially isolates from Thailand. Further analysis also showed a strong association that implicates agriculture and domestication activities as high-risk routes of infection.
CONCLUSIONS/SIGNIFICANCE: In conclusion, MLST analysis of B. pseudomallei clinical isolates from all states in Malaysia revealed low diversity and a close association to Southeast Asian isolates.

Matched MeSH terms: Bacterial Typing Techniques
Fulltext Whole-genome comparative analysis of Malaysian Burkholderia pseudomallei clinical isolates

Ghazali AK, Eng SA, Khoo JS, Teoh S, Hoh CC, Nathan S

Microb Genom, 2021 02;7(2).
PMID: 33565959 DOI: 10.1099/mgen.0.000527

Burkholderia pseudomallei, a soil-dwelling Gram-negative bacterium, is the causative agent of the endemic tropical disease melioidosis. Clinical manifestations of B. pseudomallei infection range from acute or chronic localized infection in a single organ to fulminant septicaemia in multiple organs. The diverse clinical manifestations are attributed to various factors, including the genome plasticity across B. pseudomallei strains. We previously characterized B. pseudomallei strains isolated in Malaysia and noted different levels of virulence in model hosts. We hypothesized that the difference in virulence might be a result of variance at the genome level. In this study, we sequenced and assembled four Malaysian clinical B. pseudomallei isolates, UKMR15, UKMPMC2000, UKMD286 and UKMH10. Phylogenomic analysis showed that Malaysian subclades emerged from the Asian subclade, suggesting that the Malaysian strains originated from the Asian region. Interestingly, the low-virulence strain, UKMH10, was the most distantly related compared to the other Malaysian isolates. Genomic island (GI) prediction analysis identified a new island of 23 kb, GI9c, which is present in B. pseudomallei and Burkholderia mallei, but not Burkholderia thailandensis. Genes encoding known B. pseudomallei virulence factors were present across all four genomes, but comparative analysis of the total gene content across the Malaysian strains identified 104 genes that are absent in UKMH10. We propose that these genes may encode novel virulence factors, which may explain the reduced virulence of this strain. Further investigation on the identity and role of these 104 proteins may aid in understanding B. pseudomallei pathogenicity to guide the design of new therapeutics for treating melioidosis.

Matched MeSH terms: Bacterial Typing Techniques
Characterization of Burkholderia pseudomallei isolated in Thailand and Malaysia

Radua S, Ling OW, Srimontree S, Lulitanond A, Hin WF, Yuherman, et al.

Diagn Microbiol Infect Dis, 2000 Nov;38(3):141-5.
PMID: 11109011

A total of 35 Burkholderia pseudomallei isolates from Thailand (16 clinical and eight soil isolates) and Malaysia (seven animal, two isolate each from clinical and soil) were investigated by their antimicrobial resistance, plasmid profiles and were typed by randomly amplified polymorphic DNA analysis. All isolates were found to be resistant to six or more of the 12 antimicrobial agents tested. Only two small plasmids of 1.8 and 2.4 megadalton were detected in two clinical isolates from Thailand. RAPD analysis with primer GEN2-60-09 resulted in the identification of 35 RAPD-types among the 35 isolates. The constructed dendrogram differentiated the 35 isolates into two main clusters and a single isolate. The wide genetic biodiversity among the 35 isolates indicate that RAPD-PCR can be a useful method to differentiate unrelated B. pseudomallei in epidemiological investigation.

Matched MeSH terms: Bacterial Typing Techniques
Fulltext Apibacter adventoris gen. nov., sp. nov., a member of the phylum Bacteroidetes isolated from honey bees

Kwong WK, Moran NA

Int J Syst Evol Microbiol, 2016 Mar;66(3):1323-1329.
PMID: 26743158 DOI: 10.1099/ijsem.0.000882

Honey bees and bumble bees harbour a small, defined set of gut bacterial associates. Strains matching sequences from 16S rRNA gene surveys of bee gut microbiotas were isolated from two honey bee species from East Asia. These isolates were mesophlic, non-pigmented, catalase-positive and oxidase-negative. The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 0 and C16 : 0 3-OH. The DNA G+C content was 29-31 mol%. They had ∼87 % 16S rRNA gene sequence identity to the closest relatives described. Phylogenetic reconstruction using 20 protein-coding genes showed that these bee-derived strains formed a highly supported monophyletic clade, sister to the clade containing species of the genera Chryseobacterium and Elizabethkingia within the family Flavobacteriaceae of the phylum Bacteroidetes. On the basis of phenotypic and genotypic characteristics, we propose placing these strains in a novel genus and species: Apibacter adventoris gen. nov., sp. nov. The type strain of Apibacter adventoris is wkB301T ( = NRRL B-65307T = NCIMB 14986T).

Matched MeSH terms: Bacterial Typing Techniques
Randomly amplified polymorphic DNA typing: a useful tool for rapid epidemiological typing of Klebsiella pneumoniae

Wong NA, Linton CJ, Jalal H, Millar MR

Epidemiol Infect, 1994 Dec;113(3):445-54.
PMID: 7995354

Discriminatory typing methods are invaluable in the investigation of outbreaks of infectious diseases. Single primers were used to generate randomly amplified polymorphic DNA (RAPD) profiles from Klebsiella pneumoniae isolates of various serotype and K. pneumoniae isolates from cases of sepsis at a Malaysian hospital and two English hospitals. RAPD profiles of acceptable reproducibility, a maximum of three minor band variations, were produced using a rapid DNA extraction method. RAPD typing of K. pneumoniae was shown to be as discriminatory as restriction fragment length polymorphism analysis using pulsed field gel electrophoresis yet quicker and less costly. The findings suggest that RAPD typing may be a useful tool for the epidemiological typing of K. pneumoniae.

Matched MeSH terms: Bacterial Typing Techniques*
Fulltext The significance of coagulase-negative staphylococci bacteremia in a low resource setting

Abdul Rahman Z, Hamzah SH, Hassan SA, Osman S, Md Noor SS

J Infect Dev Ctries, 2013 Jun;7(6):448-52.
PMID: 23771288 DOI: 10.3855/jidc.2535

INTRODUCTION: Coagulase-negative staphylococci (CoNS) are a group of micro-organisms that are increasingly implicated as a cause of significant infection and the leading cause of bloodstream infection (BSI). One important predictor of true BSI is the isolation of CoNS from multiple blood cultures, presuming that the isolates represent the same species. Thus the objective of this study was to determine the significance of repeated CoNS isolated from blood cultures.
METHODOLOGY: This was a prospective laboratory study which was initiated in June 2007 and lasted until July 2008. CoNS isolates were obtained from patients who had two positive blood cultures within a 14-day interval. CoNS were identified to the species level using an API-Staph, and antibiotics susceptibility testing was performed according to Clinical and Laboratory Standards Institute specifications. Strain relatedness was confirmed using pulsed-field gel electrophoresis.
RESULTS: During the study period, 202 CoNS-positive samples were isolated from 101 patients. The most common species isolated was Staphylococcus epidermidis (59.0%), and 83.2% of the patients isolated the same species of CoNS from repeated blood cultures. Among the isolates of the same species, only 40.7% had the same antibiogram. CoNS with the same species and antibiogram had 93.3% probability of belonging to the same strain. Most (65.5%) of the patients were treated with antibiotics, primarily from the glycopeptides group.
CONCLUSION: Speciation and antibiogram of CoNS from repeated blood cultures are adequate in determining the significance of repeated CoNS isolated from blood cultures.

Matched MeSH terms: Bacterial Typing Techniques
Fulltext Emerging Infectious Disease Implications of Invasive Mammalian Species: The Greater White-Toothed Shrew (Crocidura russula) Is Associated With a Novel Serovar of Pathogenic Leptospira in Ireland

Nally JE, Arent Z, Bayles DO, Hornsby RL, Gilmore C, Regan S, et al.

PLoS Negl Trop Dis, 2016 12;10(12):e0005174.
PMID: 27935961 DOI: 10.1371/journal.pntd.0005174

The greater white-toothed shrew (Crocidura russula) is an invasive mammalian species that was first recorded in Ireland in 2007. It currently occupies an area of approximately 7,600 km2 on the island. C. russula is normally distributed in Northern Africa and Western Europe, and was previously absent from the British Isles. Whilst invasive species can have dramatic and rapid impacts on faunal and floral communities, they may also be carriers of pathogens facilitating disease transmission in potentially naive populations. Pathogenic leptospires are endemic in Ireland and a significant cause of human and animal disease. From 18 trapped C. russula, 3 isolates of Leptospira were cultured. However, typing of these isolates by standard serological reference methods was negative, and suggested an, as yet, unidentified serovar. Sequence analysis of 16S ribosomal RNA and secY indicated that these novel isolates belong to Leptospira alstonii, a unique pathogenic species of which only 7 isolates have been described to date. Earlier isolations were limited geographically to China, Japan and Malaysia, and this leptospiral species had not previously been cultured from mammals. Restriction enzyme analysis (REA) further confirms the novelty of these strains since no similar patterns were observed with a reference database of leptospires. As with other pathogenic Leptospira species, these isolates contain lipL32 and do not grow in the presence of 8-azagunaine; however no evidence of disease was apparent after experimental infection of hamsters. These isolates are genetically related to L. alstonii but have a novel REA pattern; they represent a new serovar which we designate as serovar Room22. This study demonstrates that invasive mammalian species act as bridge vectors of novel zoonotic pathogens such as Leptospira.

Matched MeSH terms: Bacterial Typing Techniques
Fulltext Methicillin sensitive Staphylococcus aureus (MSSA) isolates as a potential source for the emergence of USA 300 methicillin resistant Staphylococcus aureus (MRSA) in Malaysia

Ghasemzadeh-Moghaddam H, Neela V, Goering R, Mariana NS

Trop Biomed, 2012 Sep;29(3):429-33.
PMID: 23018506

We investigated the potential of USA300 MRSA emergence in Malaysia by examining 268 MSSA isolates from both community (110) and healthcare (158) settings. Nine isolates from both the environments were similar to the USA300 MRSA background based on MLST, spa and PFGE type. These results underscore the importance of continued surveillance to monitor the emergence of USA300 MRSA in Malaysia.

Matched MeSH terms: Bacterial Typing Techniques

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