Materials and Methods: The study started with the identification of selected LAB by 16S rRNA, followed by optimization of GABA production by culture conditions using different initial pH, temperature, glutamate concentration, incubation time, carbon, and nitrogen sources. 16S rRNA polymerase chain reaction and analysis by phylogenetic were used to identify Lactobacillus plantarum (coded as N5) responsible for the production of GABA.
Results: GABA production by high-performance liquid chromatography was highest at pH of 5.5, temperature of 36°C, glutamate concentration of 500 mM, and incubation time of 84 h. Peptone and glucose served as the nitrogen and carbon sources, respectively, whereas GABA was produced at optimum fermentation condition of 211.169 mM.
Conclusion: Production of GABA by L. plantarum N5 was influenced by initial pH of 5.5, glutamic acid concentration, nitrogen source, glucose as carbon source, and incubation temperature and time.
Materials and methods: Seventy-five enterococci isolates recovered from different clinical sources were re-identified by subculturing on selective medium, Gram staining, biochemical profiling (API 20 Strep), and 16s rRNA sequencing. Antimicrobial susceptibility testing (AST) was performed using Kirby-Bauer disc diffusion, E-test, and broth microdilution methods. PCR amplification was used to detect the presence of aminoglycoside modifying enzyme (AME) genes [aac(6')-Ie-aph(2")-Ia, aph(2")-Ib, aph(2")-Ic, aph(2")-Id, aph(3')-IIIa]. Descriptive data analysis was used to analyze the antibiotic susceptibility profiles and the distribution of HLAR genes.
Results: The majority of the isolates recovered from the clinical samples are E. faecalis (66.7%), with the highest recovery from the pus. The prevalence of HLGR (51%) is higher when compared to HLSR (45-49%). Analysis of the resistance genes showed that bifunctional genes aac(6')-Ie-aph(2")-Ia and aph(3')-IIIa contributed to the HLAR E. faecalis and E. faecium. The other AME genes [aph(2")-Ib, aph(2")-Ic, aph(2")-Id] were not detected in this study.
Conclusion: This study provides the first prevalence data on HLAR and the distribution of the AME genes among E. faecalis and E. faecium isolates from Malaysia. These highlight the need for continued antibiotic surveillance to minimize its emergence and further dissemination.
RESULTS: A 300 fecal samples were collected from village chickens (n = 100), layer chickens (n = 100) and captive birds (n = 100). Fecal samples were split into two aliquots for microbiological and molecular detection of MAA. Microbiology detection consisted of microscopy (Ziehl-Neelsen staining) and culture of samples decontaminated with 1% Cetylperidinium chloride and vancomycin, nalidixic acid and amphotericin B (VNA) antibiotic cocktail [vancomycin (VAN) 100 μg/ml, nalidixic acid (NAL) 100 μg/ml and amphotericin B (AMB) 50 μg/ml] onto Löwenstein-Jensen (L-J). Molecular detection (PCR-IS901) was performed to detect MAA DNA from the feces and PCR-16S rRNA and IS901 for identification of genus Mycobacterium and Mycobacterium avium sub species avium isolated onto L-J. All samples (296) were AFB negative smear. M. avium was isolated in 0.3% (1/296) samples by culture and detected in 2.5% (6/242) samples by PCR (IS901). Other mycobacteria were found in 1.7% (5/296) chickens. Of five isolates, two were identified as Mycobacterium terrae and M. engbaekii and remaining isolates were not sequenced. Birds positive for M. avium included White Pelican (n = 1) Black Hornbill (n = 1), Macaw (n = 2), Cockatoo (n = 2) and village chicken (n = 1).
CONCLUSION: It is concluded that chickens and birds were infected with M. avium in selected areas of Peninsular Malaysia. Although, PCR is rapid, reliable and cost effective method for detection of M. avium in a subclinical stage, the culture of the avian feces should still be used as a reference test for the diagnosis of avian tuberculosis.