No abstract available.
Anti-Infective Agents*

No abstract available.
Anti-Infective Agents* ; Pneumonia*

Aims: This study is to isolate and characterize endophytic bacteria for potential industrial enzymes and antimicrobial activities against some human pathogens. Methodology and results: Mentha spicata, a local medicinal plant, was used to source for endophytes. The roots, stems and leaves of M. spicata were surface-sterilized to isolate the endophytic bacteria. The endophytic bacteria were subsequently characterized based on their 16S rRNA sequences. The endophytic bacteria were screened for both antimicrobial and enzymatic activities. We identified 15 isolates of 4 genus-Pseudomonas (7 species), Bacillus (3 species), Enterobacter (1 species) and Comamonas (1 species) with 97-100% similarity level. Isolates MSS-3 (Pseudomonas putida), MSR-4 (Pseudomonas pictorum), MSS-2 (Bacillus thuringiensis) and MSR-5 (Pseudomonas straminea) showed prominent antimicrobial activities against the pathogens tested with zones of inhibition between 6.3 to 15.3 ± 0.6 mm. All species examined have positive cellulase activities except Comamonas guangdongensis and only isolates of the Bacillus genus, Pseudomonas pictorum and P. argentinensis exhibited amylase activities. Conclusion, significance and impact of study: Our findings revealed potential therapeutic uses of the bioactive compounds of these bacteria endophytes against pathogens. Their enzymatic potential can also be of use in various industries.
Anti-Infective Agents

Aims: The aims of this study were to isolate and characterize antimicrobial producing bacteria from tropical peat swamp forest soils. Methodology and results: Bacteria isolated from peat soil were screened for antimicrobial properties via agar overlay assay. Broth microdilution was performed using crude-cell free supernatant (CCFS) to determine the minimum inhibitory concentration (MIC). One isolate was selected due to its broad spectrum activity and identified as Burkholderia spp. with a maximum identity of 99% via 16s rRNA gene PCR. This isolate was able to produce antimicrobials that were active against several Gram positive bacteria, Gram negative bacteria and also yeast. The antimicrobial activity of the CCFS was stable at a pH range of 1 to 11, temperatures of −20 °C to 80 °C, and after treatment with several proteolytic enzymes: α-chymotrypsin, proteinase K and trypsin, indicating that the antimicrobial produced might not be proteinaceous in nature. It is possible that the isolate can produce polyketides, a type of antimicrobial compound produced by Burkholderia known to be resistant to proteolytic enzymes. However, further work needs to be done to confirm this. Conclusion, significance and impact of study: The presence of antimicrobial producing bacteria signified that tropical peat swamps are indeed a potential source for antimicrobials to combat infections.
Anti-Infective Agents

Aims: The aim of the study was to investigate the antimicrobial activity of Nauclea subdita (Korth) Steud against six pathogenic microorganisms. Methodology and results: Young and matured trees of N. subdita were cut and separated into bark and wood parts, respectively, prior to extraction process. Phytochemical screening tests, antimicrobial activity, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were determined. Preliminary screening for phytochemical components showed that both young and matured tree had similar constituents. Extracts from matured tree showed more potency in terms of the zones of inhibition sizes than the young tree. Extract of N. subdita was more potent to both marine bacteria, Vibrio parahaemoliticus and V. alginolyticus, while Candida albican and Aspergillus niger were resistant to it. The sensitivity test showed that 500 µg/mL is the optimum concentration for extract of bottom sapwood of mature tree to act as bactericidal. Conclusion, significance and impact study: The results from this study suggest that N. subdita bark and wood extracts may serve as potential source of antimicrobial agents for future development in medicine applications.
Anti-Infective Agents

Aims: Pseudoalteromonas ruthenica KLPp3 is the marine Gram-negative strain isolated from the surface of mud crab at Pulau Perhentian Malaysia. In this work, the anti-biofilm activity of P. ruthenica supernatant was examined on Serratia marcescen and Vibrio alginolyticus. Methodology and results: The crude extract of P. ruthenica KLPp3 was obtained using ethyl acetate. The subminimum inhibitory concentration (MIC) of the crude extract was determined using the minimum inhibitory test. The subMIC crude extract was tested against two of the S. marcescen virulence factors, which are the swarming ability and production of prodigiosin. The crystal violet assay was used to test the anti-biofilm activity of the sub-MIC crude extract against S. marcescen and V. alginolyticus. The productions of prodigiosin were reduced by 72%. The swarming area was reduced by 56.06%. It inhibits 26.9% and 48.5% of biofilm production in S. marcescens and V. alginolyticus respectively. The crude extract was heat stable. Conclusion, significance and impact of study: Besides combating the S. marcescens virulence factor, P. ruthenica KLPp3 crude extract in sub-MIC reduces the formation of biofilm of S. marcescens and V. alginolyticus, which may find applications in biofilm inhibition and prevention.
Anti-Infective Agents

Aims: To isolate and characterize an antimicrobial peptide from fruiting bodies of Lentinus squarrosulus Mont., the Thai common edible mushroom. Methodology and results: Solid ammonium sulfate at 40-80% (w/v) final concentration was utilized to precipitate the proteins and further purified by ion exchange chromatography on DEAE-cellulose and gel filtration chromatography on Sephadex G-25. The peptide was adsorbed on DEAE-cellulose and Sephadex G-25. It appeared as a single band with a molecular mass of about 17 kDa (kilodalton) in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Further investigation of antimicrobial properties of purified peptide revealed that it has no activity against both Gram positive and Gram negative bacteria. However, it exhibited strong antifungal activity against various species of fungal pathogen of human. Among the high sensitive strains, Trichophyton mentagrophytes, T. rubrum, and Candida tropicalis are clinical isolates. Moreover, the potency was found to be concentration dependent and comparable with Ketoconazole, the commercial antifungal drug. Conclusion, significance and impact study: In this work, the novel bioactive peptide from fruiting bodies of L. squarrosulus Mont. has been isolated. It shows potent activity against various clinical isolates of fungal pathogen of human. It may have potential for pharmaceutical application.
Anti-Infective Agents

Antimicrobial peptides (AMPs) have gained increasing attention as a potential candidate in the development of novel antimicrobial agent. Designing AMPs with enhanced antimicrobial activity while reducing the cell toxicity level is desired especially against the antibiotic-resistant microbes. Various approaches towards the design of AMPs have been described and physicochemical properties of AMPs represent the primary factors determining the antimicrobial potency of AMPs. The most common parameters include net charge and hydrophobicity, which greatly influence the antimicrobial activity of AMPs. Moreover, certain amino acids would have critical importance in affecting the antimicrobial activity as well as cell cytotoxicity of AMPS. In this review, net charge, hydrophobicity, and specific amino acid residues were discussed as factors contributing to the antimicrobial activity of AMPs.
Anti-Infective Agents

Introduction: bacteremia continues to be one of the major causes of morbidity and mortality despite the existence of numerous antimicrobial agents. this study aimed to provide a Malaysian perspective on paediatric community-acquired bacteraemia based on the documentation of epidemiology and antimicrobial profile of the isolated pathogens. Method: A retrospective study was conducted by analysing clinical details, blood cultures and antimicrobial susceptibility testing results in children between the ages of 0 to 13 years old, who were admitted to selayang Hospital over an 11-year period from 2001 until 2011. there were 222 bacteraemia cases and the median age was 11.7 months. the highest number (39%) of bacteraemia cases occurred between ages one month to one year. the three most commonly isolated aetiological agents were Staphylococcus aureus (17.1%), nontyphoidal Salmonella (16.2%), and Streptococcus pneumoniae (12.6%). Almost 8% of the Staphylococcus aureus isolates were methicillin resistant, while nontyphoidal Salmonella (Nts) isolates demonstrated 18.4%, 10.5% and 2.6% resistance towards ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin respectively. All Nts isolates were sensitive to ceftriaxone. Streptococcus pneumoniae isolates showed 17.9% resistance to penicillin. skin and soft tissue infections as well as lower respiratory tract infections (63.2%) were the main foci of infections in Staphylococcus aureus bacteraemia. Acute gastroenteritis (80.0%) and pneumonia (60.8%) were the main presentations of Nts and Streptococcus pneumoniae bacteraemia respectively. Overall mortality rate was 8.1%. Conclusion: Knowledge on the local epidemiology and antibiotic resistance pattern serves as a significant platform in improving the empiric antibiotic therapy for patients with community acquired bacteraemia.
Anti-Infective Agents ; Bacteremia

No abstract available.
Anti-Infective Agents* ; Compliance*