Epidemiological observations of invasive group B Streptococcus infections in six major hospitals in Peninsular Malaysia

Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical records from patients with GBS infection isolated from the sterile site,such as blood and cerebrospinal fluid from 14 July 2019 to 15 December 2020,were reviewed from six major hospitals in Peninsular Malaysia.Inclusion criteria were invasive GBS,sterile sites and non-repeated GBS isolated from the same patients in the same admission.Viable isolates were re-identified for GBS and serotyped.Results:A total of 118 patients were eligible,with a majority of non-pregnant adults(76.3%).Over half of the patients(62.7%)had underlying medical conditions,with diabetes as the most common disease,followed by respiratory disease,renal disease,cardiovascular disease and skin and soft tissue disease.The most common manifestations were sepsis,followed by soft tissue abscess,diabetic foot ulcer,wet gangrene and cellulitis.The overall mortality was 7.6%.The most common serotype was serotype桋.Conclusions:Invasive GBS infection among non-pregnant adults showed a rising trend,particularly among diabetic individuals.The study underscores the importance of reducing risk factors and highlights the necessity of developing GBS vaccination as a preventive strategy for both infants and adults.

Disease burden,antimicrobial resistance and molecular characterization of invasive group B Streptococcus among non-pregnant adults in Malaysia:A protocol study

and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study is conducted in the selected hospitals with similar approaches.GBS isolates are subjected to phenotyping,serotyping by multiplex PCR,antimicrobial susceptibility testing and PCR-detection of GBS virulence and pilus genes.Seven housekeeping genes are amplified and sequenced for multi-locus sequence typing.Discussion:Findings from the study may contribute to the management of clinical practice to diagnose and prevent GBS related diseases in a timely manner.Prudent use of antibiotics is encouraged by monitoring antimicrobial resistance.

Molecular epidemiology of piliated pneumococcal isolates at a major tertiary hospital in the Klang Valley,Malaysia

Objective:To characterise a collection of pili-carrying and none pili-carrying pneumococcal isolates of clinical origin for serotypes,antibiotic resistance and genotype.Methods:In total,42 clinical isolates were collected between October 2017 and December 2019.Those isolates were analysed for antimicrobial susceptibility,serotype distribution,detection of pneumococcal virulence and pilus genes.Multilocus sequence typing was performed only for piliated isolates,followed by phylogenetic analysis.Results:The common isolation sites among the pneumococcal isolates were tracheal aspirate(28.6%),blood(26.2%),and sputum(23.8%).Fifty percent isolates were resistant to erythromycin,tetracycline(50.0%)and trimethoprim-sulfamethoxazole(43.0%).The most frequent were serotypes 19F(28.6%),6A/B(23.8%)and 19A(14.3%).Piliated isolates were detected in a small proportion(33.3%);64.3%were multidrug-resistant.ST320 was the prevalent sequence type among the piliated isolates and genetically related to the Pneumococcal Molecular Epidemiology Network clones Taiwan19F-14(CC271).In the phylogenetic analysis,some piliated isolates showed a close association having similar ST320,carrying serotype 19A and both pilus genes indicating their clonal spread.Conclusions:Pneumococcal lineages of piliated isolates have been globally disseminated and pili could have played a role in the spread of antibiotic resistant clones.

Inhibition mechanisms of secretome proteins from Paenibacillus polymyxa Kp10 and Lactococcus lactis Gh1 against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus

Objective:To determine the inhibition mechanisms of secretome protein extracted from Paenibacillus polymyxa Kp10(Kp10)and Lactococcus lactis Gh1(Gh1)against methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Enterococcus(VRE).Methods:The sensitivity and viability of MRSA and VRE treated with secretome proteins of Kp10 and Gh1 were determined using minimal inhibitory concentration,minimum bactericidal concentration,and time-to-kill assays.The morphological changes were observed using scanning electron microscopy and transmission electron microscopy.To elucidate the antimicrobial mechanism of secretome protein of Kp10 and Gh1 against MRSA and VRE,2D gel proteomic analysis using liquid chromatography-mass spectrometry was run by comparing upregulated and downregulated proteins,and the proton motive force study including the efflux of ATP,pH gradient,and the membrane potential study were conducted.Results:MRSA and VRE were sensitive to Kp10 and Gh1 secretome protein extracts and displayed apparent morphological and internal composition changes.Several proteins associated with cellular component functions were either downregulated or upregulated in treated MRSA and VRE by changing the membrane potential gradient.Conclusions:Kp10 and Gh1 secretome proteins reduce the growth of VRE and MRSA by damaging the cell membrane.Cell division,cell wall biosynthesis,and protein synthesis are involved in the inhibition mechanism.