Trends in antimicrobial resistance in Malaysia.

INTRODUCTION: Antibiotic resistance is a burgeoning problem worldwide. The trend of bacterial resistance has increased over the past decade in which more common bacteria are becoming resistant to almost all the antibiotics currently in use, posing a threat to humans and even livestock. METHODS: The databases used to search for the relevant articles for this review include PubMed, Science Direct, and Scopus. The following keywords were used in the search: Antimicrobial resistance, Malaysian action plan, antibioticresistant bacteria, and Malaysian National Surveillance on Antimicrobial Resistance (NSAR). The relevant articles published in English were considered. RESULTS: The antibiotic-resistant bacteria highlighted in this review showed an increase in resistance patterns to the majority of the antibiotics tested. The Malaysian government has come up with an action plan to create public awareness and to educate them regarding the health implications of antibiotic resistance. CONCLUSION: Antimicrobial resistance in Malaysia continues to escalate and is attributed to the overuse and misuse of antibiotics in various fields. As this crisis impacts the health of both humans and animals, therefore a joined continuous effort from all sectors is warranted to reduce the spread and minimize its development.

Distribution of virulence genes and the molecular epidemiology of Streptococcus pyogenes clinical isolates by emm and multilocus sequence typing methods.

BACKGROUND: Streptococcus pyogenes has a variety of virulence factors and the predominant invasive strains differ according to specific emm types and geographical orientation. Although emm typing is commonly used as the gold standard method for the molecular characterisation, multilocus sequence typing (MLST) has become an important tool for comparing the genetic profiles globally. This study aimed to screen selected virulence genes from invasive and non-invasive clinical samples and to characterise the molecular epidemiology by emm typing and MLST methods. MATERIALS AND METHODS: A total of 42 S. pyogenes isolates from invasive and non-invasive samples collected from two different tertiary hospitals were investigated for the distribution of virulence factors and their molecular epidemiology by emm and multilocus sequence typing methods. Detection of five virulence genes (speA, speB, speJ, ssa and sdaB) was performed using multiplex polymerase chain reaction (PCR) using the standard primers and established protocol. Phylogenetic tree branches were constructed from sequence analysis utilised by neighbour joining method generated from seven housekeeping genes using MEGA X software. RESULTS: Multiplex PCR analysis revealed that sdaB/speF (78.6%) and speB (61.9%) were the predominant virulence genes. Regardless of the type of invasiveness, diverse distribution of emm types/subtypes was noted which comprised of 27 different emm types/subtypes. The predominant emm types/subtypes were emm63 and emm18 with each gene accounted for 11.8% whereas 12% for each gene was noted for emm28, emm97.4 and emm91. The MLST revealed that the main sequence type (ST) in invasive samples was ST402 (17.7%) while ST473 and ST318 (12% for each ST) were the major types in non-invasive samples. Out of 18 virulotypes, Virulotype A (five genes, 55.6%) and Virulotype B (two genes, 27.8%) were the major virulotypes found in this study. Phylogenetic analysis indicated the presence of seven different clusters of S. pyogenes. Interestingly, Cluster VI showed that selected emm/ST types such as emm71/ST318 (n=2), emm70.1/ST318 (n=1), emm44/ST31 (n=1) and emm18/ST442 (n=1) have clustered within a common group (Virulotype A) for both hospitals studied. CONCLUSION: The present study showed that group A streptococcci (GAS) are genetically diverse and possess virulence genes regardless of their invasiveness. Majority of the GAS exhibited no restricted pattern of virulotypes except for a few distinct clusters. Therefore, it can be concluded that virulotyping is partially useful for characterising a heterogeneous population of GAS in hospitals.