Escherichia coli sequence type 131 (ST131) carries multiple drug resistance (MDR) genes as well as virulence genes. Drug resistant characteristics give a management problem to health care personnel. Four MDR Escherichia coli ST131 H30-Rx subclones were identified among 80 Uropathogenic E. coli (UPEC) isolates by using 4 allelic-specific Polymerase Chain Reactions (PCR) in two hospitals of Kota Kinabalu, Sabah, Malaysia. There is emergence of multidrug resistant E. coli in Kota Kinabalu.
The three plasmid borne alternative dihydropteroate synthetase (DHPS) genes namely sul1, sul2 and sul3 genes were heterologous in amino acid sequence and have about 40 – 50% identity. However, they have same DHPS activity with disc diffusion zone size of 6 mm with suphamethoxazole disc in our previous study. Sul1, sul2 and sul3 genes were observed in sulphamethoxazole resistant uropathogenic Escherichia coli (UPEC). In this study, all the three genes were cloned into E. coli host and minimum inhibitory concentration (MIC) was investigated for each sul gene to compare the activities of sul genes. The MIC values of E.coli containing sul2, sul1 and sul3 genes inserted recombinant plasmid were observed to have 18.5 mg/ml, 18 mg/ml and 17.5 mg/ml respectively as mean value of five experimental results. Although comparable MICs were obtained as a result, the MIC value was highest in E. coli carrying sul2 gene indicating that this DHPS enzyme activity of sul2 was strongest among three sul genes.
Out of bacteria which cause food –borne infections, enterohemorrhagic Escherichia coli (EHEC) is
well known to be pathogen causing serious outbreaks. The first outbreak of EHEC infection occurred
in 1982 was due to ingestion of hamburger at restaurant. A rare Escherichia coli serotype, 0157:H7
was isolated at that time and the following outbreaks were mostly due to this serotype. However, O26,
O111 and O104 were also responsible for EHEC outbreaks. Enterohemorrhagic E. coli is an important
food and water-borne pathogen. Verotoxins (VTs) produced by this pathogen causes painful
hemorrhagic colitis along with major complications of hemolytic uremic syndrome (HUS). The
morbidity and significantly high mortality and enormous economic loss are problematic to the health
care administrators and EHEC infection is a serious public health issue. Another factor which makes
it high transmissibility is the low infectious dose. The German O104:H4 epidemic was caused by the
pathogen carrying a combination of virulence genes derived from two well-known pathogens, EHEC
and enteroaggregative E. coli (EAEC). There is a possibility that two mobile DNA elements can occur
again in this versatile pathogen. In this article, some aspects of EHEC infections which were
established but not well known to the medical personals were explained to get understanding of why
this infection should not be overlooked and should be under surveillance.
Toxigenic strains of Vibrio cholerae serogroup O1 and O139 are causative agents of deadly
diarrheal disease named cholera. Vibrio cholerae O1 is traditionally divided into two
biotypes, classical and El Tor, which are different in phenotypic as well as genotypic traits.
Since 1961, classical strains of Vibrio cholerae O1 serogroup has become obsolete as the
cause of epidemic and pandemic cholera and replaced by El Tor strains. Since 2002, atypical
O1 El Tor strains possessing the traits of classical strains have been increasingly recognized
as the cause of cholera in many countries across the world. This article focuses on the genetic
traits of O1 classical and El Tor strains. Furthermore, an overview of emergence of atypical
O1 El Tor strains and their genetic traits is presented.
Emergence of multidrug resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB) is one of the reasons why tuberculosis (TB) continues to cause great mortality and morbidity in less-developed countries. The development of rapid diagnostic methods targeting genetic mutations associated with resistance to the anti-tuberculous drugs is essential to fight this deadly pathogen. Isoniazid (INH) has been included in the multidrug regimens for the treatment of drug-susceptible TB for the decades. In the worldwide setting, isoniazid resistance was highly prevalent and was observed in one of every seven TB cases. Since katG315 mutation is highly prevalent, the common mutation in the enzyme essential for the activation of the INH concerned with the mechanism of drug resistance and associated with high level resistance to INH, katG315 mutation was necessary to be identified by molecular method as a molecular determinant of INH resistant Mycobacterium tuberculosis. The prevalence of katG315 mutation in various countries was discussed in this report and a new molecular method for the detection of the mutation was proposed.
Introduction: Tuberculosis (TB) still remains a public health problem worldwide and the emergence of drug resistant TB (DR-TB) has worsened the situation as it is difficult and expensive to treat. The characterization of the genetic mutations underlying streptomycin resistance may be helpful in developing rapid detection methods which may guide clinicians in making therapeutic decisions. The aim of this study is to detect mutations causing streptomycin (STR) resistance in Mycobacterium tuberculosis isolates from Sabah. Methods: Susceptibility testing was carried out in MGIT system for 42 Mycobacterium tuberculosis clinical isolates. The drug resistant isolates were subject to whole genome sequencing and in-silico analysis was performed to detect the mutations in the sequence of the rpsL gene known to confer resistance to anti-tuberculous drugs. Results: Of the 42 positive isolates, 27 (64.3%) are shown to be susceptible towards first line drugs (FLDs) while 15 (35.7%) isolates were mono- and multiple resistant to the FLDs. Our findings reveal that the isolate 145 possess mutations at codon 43 within rpsL gene with amino acid change A to G (K43R). Conclusion: Findings from this study enable us to expand our knowledge of mutations causing drug resistance in Mycobacterium tuberculosis and the point mutations, which can be used as the potential marker for detection of drug resistant isolates.
Introduction: Tuberculosis (TB) is the ninth leading cause of mortality in the world while it is the most prevalent infection which is ranked abolve HIV/AIDS. In Malaysia, tuberculosis is still a public health problem. Sabah State on Malaysian Borneo had 20-30% of total TB cases of the country. In Sabah, case notification rate of almost 200 per 100,000 population was still present in the last 10 years. Hotspots are defined as TB notification rate more than 100/100.000 in a district or TB notification rate more than 100/100,000 in the squatters’ area. In this study, cycle threshold (ct) values in GeneXpertMTB/RIF (Xpert) were tried to be correlated with growth in Mycobacterim growth indicator tubes (MGIT) by measurement of time to detection (TTD). Methods: Sputum samples from six hotspots of Kota Kinabalu were studied by Xpert as well as MGIT culture after processing of sputum samples. The correlation between Mean ct value of Xpert and TTD in MGIT was analysed by using IBM SPSS Statistic 25 and the statistical test used was Pearson Correlation test. Results: The results of Xpert indicated 35 of 204 sputum samples were pos-itive whereas only one sample was rifampicin resistant. The mean ct values were very low, low and medium in all the hotspots with sputum from one hotspot showed medium ct values predominantly. The sputum from remaining hotspots showed mainly very low and low ct values. MGIT results showed no growth in five samples with two very low, two low and one medium mean ct values. Conclusion: The finding indicated that there were correlations be-tween mean ct values of Xpert and TTD in MGIT with a few exceptions.