Aims: The aim of this research is to explore the presence of multidrug-resistance (MDR) Acinetobacter baumannii strains isolated from hospitalized patients in a tertiary-care center, Subang Jaya, Selangor, Malaysia and to compare their genotypic and phenotypic characteristics. Methodology and results: Clonal relationships were determined by multilocus sequence typing (MLST) and biofilm forming ability was evaluated by using 2, 3 - bis (2 - methoxy - 4 - nitro - 5-sulfophenyl) - 5 - [(phenylamino) carbonyl] - 2H-tetrazolium hydroxide (XTT) reduction assay in microplates and Congo red agar method (CRA). Four virulence genes coding for A. baumannii pilus usher-chaperone assembly protein, csuE gene; outer membrane protein, ompA gene; biofilm poly-β-1, 6-Nacetylglucosamine (PNAG) synthesis protein, pgaA gene; and acinetobactin-mediated iron acquisition protein, bauA gene were searched for in a collection of strains. Antimicrobial resistance against 11 antibiotics were studied by broth microdilution method. Seventeen A. baumannii clinical strains were isolated and MLST showed that the strains belonged to 5 distinct sequence types (STs), namely, ST-6, ST-265, ST-324, ST-325 and ST-432. Fiftythree percent of the strains were resistant to 4 or more antibiotics. Twelve strains produced biofilm and out of them, 4 were strong biofilm producer, besides, these strong biofilm producers were MDR strains and belongs to ST-6. In addition, all strains were ompA positive, biofilm producing strains were csuE and pgaA positive and only strong biofilm producing strains were bauA positive. Conclusion, significance and impact study: Our study demonstrates that the ST-6 strains in Malaysia could represent MDR, capable of forming strong biofilm and possess csuE, ompA, pgaA and bauA genes, virulence characteristics that probably help the bacteria to persist and cause infection.
Acinetobacter baumannii

Aims: Acinetobacter baumannii has been identified as one of the six most pathogenic bacteria that is the cause of most hospital bacterial infections according to Infectious Disease Society of America (IDSA). These nosocomial pathogens are notorious worldwide due to its ability in causing lethal infections among immunocompromised patients and its resistance to many strong antibiotics. This study aims to compare the expressed proteins of two A. baumannii strain, ATCC 19606 and a pathogenic clinically isolated strain known as AB-13. Methodology and results: AB-13 clinically strain was isolated from the lower respiratory tract of a patient with pneumonia. In this study, the proteomic profile of both ATCC 19606 and AB-13 are produced using 2-dimensional gel electrophoresis. The total protein contents were extracted, quantified and separated using 2-DE with a pH range of 4-7 to acquire the proteomic profile for comparison. The final analytical gel was analysed using Delta2D software and among the 324 protein spots successfully resolved, 10 spots exhibited signs of differential expression with 7 spots found to be downregulated and 3 spots upregulated (p< 0.01). These differences could signify the evolution AB-13 has undergone as it acquires traits ultimately aiding in its survivability, antimicrobial resistance and pathogenicity within varied environments especially during infections. Conclusion, significance and impact of study These findings support the presence of variation in AB-13 from a proteomic perspective, highlighting the pathogen’s evolution improving survivability and pathogenicity, warranting in-depth exploration towards understanding A. baumannii virulence and pathogenicity.
Acinetobacter baumannii--pathogenicity ; Two-Dimensional Difference Gel Electrophoresis ; Proteomics