Aggregatibacter actinomycetemcomitans Endocarditis in a Patient with Chronic Periodontitis: A Case Report

@#The HACEK organisms consist of the non-influenzae Haemophilus sp., Aggregatibacter sp., Cardiobacterium sp., Eikenella corrodens and Kingella sp. are responsible for a sizable percentage of infective endocarditis cases worldwide with the mortality rate of 18%. Amongst them, Aggregatibacter actinomycetemcomitans is the most common pathogen strongly associated with infective endocarditis. A. actinomycetemcomitans forms part of the oral microbiota and is also the etiological agent of periodontitis. Here, we present a case of a 37-year-old man with underlying obstructive uropathy, that sought treatment for postural hypotension and symptomatic anaemia with fever. Later, he had developed decompensated congestive cardiac failure with aortic regurgitation. A cardiac echocardiogram revealed the presence of vegetation on the aortic valve. Blood culture grew A. actinomycetemcomitans, and he was treated with furosemide and ceftriaxone. A further dental examination showed the patient is having chronic periodontitis, which could be the possible source of A. actinomycetemcomitans causing infective endocarditis. The patient was then transferred to the National Heart Centre for the first time for further management after completion of 4 weeks of intravenous antibiotics. As the pathogen is fastidious, rapid and newer technology like MALDI-TOF mass spectrometry provides rapid and accurate identification for appropriate patient clinical management.

Comparison of Automated and Manual Viral Nucleic Acid Extraction Kits for Covid-19 Detection Using qRT-PCR

@#Introduction: The emergence of a novel Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a pandemic. Rapid and accurate diagnosis method is crucial to reduce the disease burden and to improve early diagnosis approaches to control of the disease. Real time Reverse transcriptase PCR (qRT-PCR) has been identified by the World Health Organization as the most sensitive and specific method of detection. However, the success of this assay relies on the quantity and quality of the extracted viral RNA. Methods: Various methods have been developed for nucleic acid extraction however, the methods have not been assessed. RNA extraction was performed from 24 nasopharyngeal swab samples using a manual extraction kit (GF-1) and an automated extraction kit (Genolution). The concentration and purity of the extracted RNA samples were measured, and its performance were tested using qRT-PCR. Results: The average concentration and purity of the RNA samples extracted using GF-1 kit was higher compared to Genolution. Similarly, the qRT-PCR assay using the RNA samples extracted using manual extraction was better compared to automated kit. Conclusion: Both the manual and automated extraction kits have its advantages and disadvantages in terms of yield and purity. However, with proper optimization, both methods may be used for routine molecular diagnostic of COVID-19 in laboratories.

Occupational exposure and challenges in tackling M. bovis at human-animal interface: a narrative review.

Zoonotic tuberculosis caused by Mycobacterium bovis (M. bovis), a member of Mycobacterium tuberculosis complex (MTBC) has increasingly gathered attention as a public health risk, particularly in developing countries with higher disease prevalence. M. bovis is capable of infecting multiple hosts encompassing a number of domestic animals, in particular cattle as well as a broad range of wildlife reservoirs. Humans are the incidental hosts of M. bovis whereby its transmission to humans is primarily through the consumption of cattle products such as unpasteurized milk or raw meat products that have been contaminated with M. bovis or the transmission could be due to close contact with infected cattle. Also, the transmission could occur through aerosol inhalation of infective droplets or infected body fluids or tissues in the presence of wound from infected animals. The zoonotic risk of M. bovis in humans exemplified by miscellaneous studies across different countries suggested the risk of occupational exposure towards M. bovis infection, especially those animal handlers that have close and unreserved contact with cattle and wildlife populations These animal handlers comprising of livestock farmers, abattoir workers, veterinarians and their assistants, hunters, wildlife workers as well as other animal handlers are at different risk of contracting M. bovis infection, depending on the nature of their jobs and how close is their interaction with infected animals. It is crucial to identify the underlying transmission risk factors and probable transmission pathways involved in the zoonotic transmission of M. bovis from animals to humans for better designation and development of specific preventive measures and guidelines that could reduce the risk of transmission and to protect these different occupational-related/populations at risk. Effective control and disease management of zoonotic tuberculosis caused by M. bovis in humans are also hindered by various challenges and factors involved at animal-human interface. A closer look into factors affecting proper disease control and management of M. bovis are therefore warranted. Hence, in this narrative review, we have gathered a number of different studies to highlight the risk of occupational exposure to M. bovis infection and addressed the limitations and challenges underlying this context. This review also shed lights on various components and approaches in tackling M. bovis infection at animal-human interface.

Diagnosis of neonatal meningitis: Is it time to use polymerase chain reaction?

@#Group B Streptococcus (GBS) is a predominant causative pathogen of neonatal meningitis that is associated with a high rate of mortality and morbidity. The establishment of antenatal screening and intrapartum chemoprophylaxis has led to a significant reduction in the incidence rate of invasive GBS disease in developed countries. However, these strategies are not routinely practiced in most developing countries. To ensure good recovery of infants affected with GBS, a prompt diagnostic strategy and appropriate therapy are essential. We highlight here the case of a preterm male infant diagnosed with early-onset of GBS meningitis diagnosed by using polymerase chain reaction (PCR) method on the cerebrospinal fluid (CSF) of the infant. Initially the pathogen was not isolated in both blood and CSF cultures as sampling was performed after the administration of antibiotics. Hence, PCR was a crucial diagnostic test in facilitating the detection of the pathogen in CSF. We believe that PCR is a potentially fast and precise diagnostic method for infection in a newborn.

A Rare Case of Haemophilus parahaemolyticus Pneumonia

@#Pneumonia is a common lung infection. Common bacterial cause of this serious lung infection includes Streptococcus pneumoniae, Haemophilus influenzae and Mycoplasma pneumoniae. Haemophilus parahaemolyticus pneumonia is an uncommon cause of bacterial pneumonia, occurring mainly as an opportunistic pathogen in immunocompromised patients as in this case, diabetes mellitus. Therefore, this case report will look at a case of 49-year-old man who was diagnosed with this uncommon pathogen which was successfully eradicated with antibiotics. This case report will look at a case of 49 years old who was diagnosed with this uncommon pathogen which was successfully eradicated with antibiotics.

Suppurative BCG Lymphadenitis and the Importance of Microbiology Investigations – A Case Report

@#Suppurative BCG lymphadenitis can easily be overlooked, as it mimics other diseases such as tuberculous lymphadenitis. A case of a three-month old female infant who received the BCG vaccination at birth presented with isolated left axillary mass at two months of age. She was initially treated as lymph node abscess but was referred to the hospital due to the increasing size of the swelling. Needle aspiration was done and the microbiology analysis came out positive for acid-fast bacilli. She was planned for syrup isoniazid; however, the management team withheld treatment until they were certain of the identity of the bacteria. The bacteria was confirmed by the molecular method to be Mycobacterium bovis BCG strain. The case report highlights the importance of the microbiology investigations for appropriate management in this case.

It was a Fungal Culprit all Along - A Case Report

@#Sporotrichosis is a relatively uncommon fungal infection in human as compared to other fungal infectiction such as tinea corporis or cruris. The fungus can be found in the environment and on plant matter. Sporotrichosis usually results from trauma to the skin followed by exposure to the fungus. It can also be spread by cat scratch or bite. Sporotrichosis usually presents as multiple skin nodules arranged in a linear fashion over the limbs, often with associated lymphadenopathy. This calls for importance of full physical examination and a high index of suspicion in order to diagnose this infection that can either involve the skin or the lymphatic channel or both. If misdiagnosed, treatment can be delayed and lead to prolonged suffering of the patient. This is an interesting case report about a 43-year-old woman who presented with left axillary swelling and decreased range of movement of the corresponding shoulder which was feared initially to be linked to breast cancer. However, good clinal acumen lead to the actual diagnosis of sporotrichosis.

Prevalence of Chlamydia trachomatis among Subfertile Couples of LPPKN Subfertility Clinic

@#Introduction: Chlamydia trachomatis is the most prevalent sexually transmitted infection world wide caused by the bacterial agent named Chlamydia trachomatis. Long term chlamydial infection has a negative impact on the female reproductive system and often leads to infertility. We determined the prevalence of Chlamydia trachomatis and its associated factors among subfertile couples attending the Lembaga Penduduk dan Pembangunan Keluarga Negara (LPPKN) Subfertility Clinic. Method: Blood samples were collected from 95 couples (190 respondents) for Chlamydia trachomatis IgG antibody testing. The Enzyme-Linked Immunosorbent Assay (ELISA) technique was used to detect outer membrane protein complexes of Chlamydia trachomatis in the assay. Results: Chlamydia trachomatis IgG antibody seropositivity was detected in 14 husbands (14.7%) and 17 wives (17.9%). The prevalence of Chlamydia trachomatis among these couples was 22.1%. Our findings found no significant association between Chlamydia trachomatis and its associated factors, but the prevalence rate among the studied population is of concern. Conclusion: The screening of Chlamydia trachomatis among couples is recommended for integration in the subfertility investigation procedure. It is crucial, particularly for women with tubal factor infertility (TFI).

Knowledge and Attitude Towards Vaccine Preventable Diseases and Vaccination Among Prospective Malaysian Hajj Pilgrims in Klang Valley, Malaysia

@#Introduction: Hajj is a unique religious mass gathering among Muslims hosted by Kingdom of Saudi Arabia (KSA) annually. It is a fifth pillar that is compulsory to be carried among muslim. Infections due to Neisseria meningitidis, Streptococcus Pneumoniae and Influenza virus are very high among Hajj pilgrims in KSA. Study shows knowledge and attitude towards vaccine preventable disease and vaccination which is very important for the prevention of these infectious diseases. This study aims to determine knowledge and attitude among the prospective Malaysian hajj pilgrims on vaccine preventable disease and vaccination. Method: A cross sectional study was conducted among prospective hajj pilgrims in June 2019. Self-administered questionnaires were given to the respondents through simple random sampling. The socio-demographic characteristics were described using descriptive analysis. Chi-square test was used to analyse the association between the socio-demographic and Malaysian hajj pilgrims’ knowledge and attitude towards the vaccine preventable diseases and vaccination. Results: A total of 135 respondents were recruited in the study. There were statistically significant associations between the knowledge and the highest education level (p=0.01), and also between the knowledge and the occupation (p=0.02) on vaccine preventable disease and vaccination. Conclusion: There is a lack of knowledge among the Malaysian hajj pilgrims about these vaccine preventable diseases and vaccination, especially those who have lower education level and also unemployed. Tabung Haji are highly advised to focus on these group and prepare a special course that focused on these vaccine preventable diseases so that Malaysian Hajj pilgrims will be protected.

Multilocus Sequence Typing Analysis of Invasive and Non-Invasive Group B Streptococcus of Hospital Origin in Malaysia

@#The aim of this study was to study the genotype of a hospital collection of Group B Streptococcus (GBS) from invasive and non-invasive sites. Fifty-one pre-characterised human of GBS were re-identified and further analysed by multilocus sequence typing (MLST) in relation to previously published serotypes. Fifteen sequence types (ST) were found with ST1 being the most predominant. ST1 was also associated with majority of the invasive isolates. The genotypic distribution patterns of GBS in this study were largely in agreement with previous reports from other countries indicating the tendency of certain genotypes to prevail in human infection settings.

Nasal colonisation, antimicrobial susceptibility and genotypic pattern of Staphylococcus aureus among agricultural biotechnology students in Besut, Terengganu, east coast of Malaysia.

BACKGROUND: This study aimed to profile the antimicrobial susceptibility and presence of resistance and virulence genes of methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA nasal carriage, by means of genotypic analyses, in students of a tertiary institution in the state of Terengganu, east coast of Malaysia. METHODS: A total of 370 agricultural biotechnology students from Universiti Sultan Zainal Abidin in Besut, Terengganu, were enrolled in this study. Antimicrobial susceptibility profiles were evaluated by standard methods. PCR detection of resistance and virulence genes was performed on S. aureus that were methicillin-resistant, macrolide-lincosamide-streptogramin B (MLSB )-positive phenotype and/or positive for the leukocidin (pvl) gene followed by staphylococcal cassette chromosome mec (SCCmec), staphylococcal protein A (spa) and accessory gene regulator (agr) typing. RESULTS: One hundred and nineteen of 370 students carried S. aureus (32%); 18 of the isolates were MRSA (15%). Erythromycin resistance was detected in 20% (24/119) of which 15% (18/119) were MRSA and 5% (6/119) MSSA. Among the 24 erythromycin-resistant isolates, D-test was positive in 29% (7/24) displaying inducible MLSB , whereas the remaining 71% (17/24) showed constitutive MLSB phenotypes. Nine (7.6%) of 119 isolates were pvl positive: 44% MRSA (4/9) and 56% MSSA (5/9). Staphylococcal surface protein sasX gene was present in 92% of MRSA and 8% of MSSA isolates. The majority of MRSA isolates were agr type I (15/18; 83%). Five spa types identified with spa t037 were predominant, followed by spa types (t304 and t8696) as newly reported Malaysian MRSA in a community setting. CONCLUSION: The presence of MRSA with SCCmec of hospital-associated features and globally recognised spa types in community setting is worrisome. Furthermore, the presence of MLSB strains among multidrug-resistant (MDR) S. aureus with sasX as well as pvl-positive isolates highlights the potential risk of a community setting in facilitating the dissemination of both virulence and resistance determinants.

Approaches of Learning among Medical Undergraduates of Faculty of Medicine and Health Sciences, Universiti Putra Malaysia in 2016

@#Introduction: Challenge arises for medical undergraduates as the subject of medicine is intricate and extensive. Although students come from the same pool of excellent academic background, the medical undergraduates are still prone to failure in exams, resulting in them repeating the year of study or even having the thought of changing to other courses. In order to cope with the programme, students may adopt learning approaches that would help them to go through the programme.Therefore, it would be interesting to explore the learning approaches of medical students in Universiti Putra Malaysia. Methods: The purposes of this study were to determine the learning approach of medical undergraduates of Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (FMHS, UPM) together with its associated factors, which were socio-demographic characteristics and learning environment. This research was a cross-sectional study where the sample size calculated was 554. Self-administered questionnaires were given to the respondents chosen by simple random sampling. The socio-demographic characteristics were analysed using descriptive statistics such as frequency and percentage. Chi-square test was used to analyse the association between the variables. Results: The response rate was 83% (460 respondents agreed to participate). The majority of the respondents were females (73.7%), Malay (67%), and in their clinical years of study (58.7%). Overall, most students preferred deep approach (DA) of learning (49.6%), followed by strategic approach (29.1%) and surface apathetic approach (21.3%) of learning. There were statistically significant associations between learning approach and gender (p=0.005), as well as between learning approach and year of study (p=0.037). Conclusion:Our study showed an association between learning approaches and year of study and gender. DA of learning was the preferred learning approach in medical students at FMHS, UPM. This approach of learning, where students learn to understand the subject matter, may result in students become effective learners. Their understanding about the subject matter will be applicable to their clinical practice in the future.

Colistin-associated nephrotoxicity among patients in intensive care units (ICU) of hospitals in Selangor

Introduction: The increasing trend of extensively drugresistant gram negative bacteria responsible for nosocomial infections has prompted resurgence colistin usage. Colistin-induced nephrotoxicity is a concern with disparity in the reported rates between previous studies. This study aims to evaluate colistin-induced nephrotoxicity among Malaysian population. Methods: The medical records of ICU patients receiving colistin therapy in Hospital Serdang and Hospital Sungai Buloh from 2010 to 2012 were retrospectively reviewed. Demographics data, treatment characteristic as well as culture result and creatinine level were documented. Nephrotoxicity was determined based on RIFLE criteria. Results: A total of 100 patients were included. Median daily dose, cumulative dose and duration of colistin therapy were 3.0 MIU (IQR: 4, range 1-12), 17.8 MIU (IQR: 31.5, range 2-180) and seven days (IQR: 4, range 1-30). Nephrotoxicity was found in 23% of the study population. All cases were reversible but marginally associated with higher mortality. No statistical association exist between age, gender and race as well as administration routes with nephrotoxicity by univariable analysis. The association of dose and duration with nephrotoxicity was also not significant by univariable analysis. After adjustment for confounders, statistical association between the independent variables and dependent variable remains not significant. Conclusion: Lower dose and shorter duration in local settings contribute to lack of association between colistin therapy and nephrotoxicity in this study. Higher dosing regimen with loading dose application has been introduced in the latest National Antibiotic Guideline. Further evaluation of colistin-induced nephrotoxicity and potential risk factors is therefore warranted.

Genotypic and phenotypic characterization of methicillin resistance determinants and β-lactamase in Staphylococcus species

Aims: To characterize the genotypic distribution of mec complex, bla complex, methicillin-resistance level (cefoxitinMIC) and β-lactamase activity in carriage methicillin-resistant Staphylococcus species for a potential correlation. Methodology and results: Biochemical test, 30 µg cefoxitin diffusion disc test, cefoxitin E-test, mec and bla complexes distributions, Pbp2a and β-lactamase assays were conducted to characterize phenotypic and genotypic of MRSA and MRCoNS in our collection. Phylogenetic tree was constructed using MEGA6 software to trace the diversity of blaZ gene of MRSA and MRCoNS. Sixteen MRSA and nineteen MRCoNS were identified by biochemical tests followed by 30 µg cefoxitin antibiotic disc susceptibility test and mecA gene screening. Twenty nine isolates carry complete mecA genes (2.1 kb), incomplete mec regulator (negative or truncated) and positive Pbp2a assay for both MRSA and MRCoNS. Only MRCoNS SC177 isolate with cefoxitin MIC of 32 µg/mL carries complete mec complex. Thirty-one of thirty-five isolates carry complete bla complex (blaZ, blaRI, blaI) with 10 MRSA produce strong β-lactamase and cefoxitin MIC of ≥12 µg/mL. Only 4 MRCoNS with cefoxitin MIC of ≤8 µg/mL produce strong β-lactamase. The diversity of blaZ gene was demonstrated by phylogenetic analysis and unusual amino acid mutation at position 145 for MRSA SA60 isolate may compromise its β-lactamase activity with low cefoxitin MIC level (2 µg/mL). Conclusions, significance and impact of the study: Isolates that carry complete complete mecA gene were largely consistent with the expression of Pbp2a. Nevertheless, there is no clear correlation of mec regulator genes in relation to cefoxitin-MIC in both methicillin resistant (MR) Isolates that carry Staphylococcus species. On the other hand, various expression level of β-lactamase may correlate with cefoxitin-MIC level in MRSA as compared to MRCoNS.

Comparative Analysis of Inflammatory Markers Produced by Macrophages Inoculated with Invasive and Colonizing Strains of Streptococcus Agalactiae (Group B Streptococcus) and Evaluation of Patients’ Clinical Data

Introduction: Group B Streptococcus (GBS), infection and recurrence in newborns and pregnant women can lead to chronic medical illness resulting in significant morbidity, and mortality. Pathogenesis of GBS may be due to reasons such as activation of the immune system, followed by the production of inflammatory markers and toxic components by immune cells including macrophages. Methods: The studies on invasive and colonizing GBS strains inoculated either with peripheral or brain macrophages, the expression of nitric oxide (NO), cell viability, and CD40 were also measured by Griess assay, methyl tetrazolium assay (MTT), and flow cytometry, respectively. Furthermore, the clinical manifestations of the selected patients were also assessed for this study. Results: Outcome of inflammatory markers studies, after GBS inoculation indicated that, invasive GBS strains induced higher inflammatory markers in comparison to colonizing GBS strains. Furthermore, patients’ clinical data showed that patients with invasive GBS infections had severe condition unlike among patients with colonizing GBS strains. The fatality rate in patients with invasive GBS strain were 30.8% while there was no death among carriers. Conclusion: This study, aimed to understand the immune response to GBS, and strengthen the knowledge on GBS pathogenesis. It was concluded that invasive GBS strains not only showed higher expression of inflammatory markers on immune cells but also had higher pathogenesis effect in comparison to colonizing GBS strains.

An update on Gardneralla vaginalis associated bacterial vaginosis in Malaysia

Objective To update the status of Gardnerella vaginalis (G. vaginalis) as a causative agent of bacterial vaginosis (BV) in Malaysia and to define its epidemiology, metronidazole resistance and virulence properties. Methods It is a single-centre (Gynaecology clinic at the Hospital Kuala Lumpur, Malaysia) prospective study with laboratory-based microbiological follow up and analyses. Vaginal swabs collected from the patients suspected for BV were subjected to clinical BV diagnosis, isolation and identification of G. vaginalis, metronidazole susceptibility testing, vaginolysin and sialidase gene PCR, Piot's biotyping and amplified ribosomal DNA restriction analysis (ARDRA) genotyping. Results Among the 207 patients suspected for BV, G. vaginalis was isolated from 47 subjects. G. vaginalis coexisted with Trichomonas vaginalis and Candida albicans in 26 samples. Three G. vaginalis isolates were resistant to metronidazole. Biotyping revealed 1 and 7 as the common types. ARDRA genotype II was found to be more common (n = 22; 46%) than I (n = 12; 25.53%) and III (n = 13; 27.6%). All genotype I and III isolates carried the sialidase gene, while 91.6% and 84.6% contained the vaginolysin gene. Genotype I was significantly associated with post-gynaecological surgical complications and abortions (P = 0.002). Conclusions The existence of pathogenic G. vaginalis clones in Malaysia including drug resistant strains should not be taken lightly and needs to be monitored as these may bring more complications especially among women of child bearing age and pregnant women.

Clinical presentation and microorganisms sensitivity profile for diabetic foot ulcers: a pilot study

SUMMARY Introduction: Patients suffering from diabetes mellitus (DM) frequently present with infected diabetic foot ulcers (DFU). This study was done to record the anatomical site and the grade of ulcers according to Wagner’s classification and to culture the microorganisms from the ulcers and determine their antibiotic sensitivity. Materials and methods: Prospective study was conducted on 77 diabetic patients who were admitted with DFU from June until December 2011. Patients with end stage renal failure, those who had previous vascular surgery on the involved limb, or hyperbaric oxygen or maggot therapy for the ulcers, or had unrelated skin diseases around the involved foot were excluded from the study. Specimens for culture were obtained by a sterile swab stick or tissue sample was taken from the wound with sterile surgical instruments. Results: Wagner’s grade III and IV ulcers were most common. Majority of the ulcers involved toes (48%). Gram negative microorganisms were predominantly isolated (71.1%). Gram positive microorganisms were less frequently cultured (27.7%). Fungus was cultured from one sample (1.2%). Gram negative microorganisms were sensitive to aminoglycosides, cephalosporins or β-lactamase inhibitors. More than 40% were resistant to ampicillin. Gram positive microorganisms were sensitive to cloxacillin. MRSA were sensitive to vancomycin. Conclusion: Empirical use of antibiotics should be curtailed to prevent development of drug resistant strains of microorganisms and MRSA. We suggest use of antiseptic solutions to clean the ulcers until antibiotic sensitivity report is available. Results of our altered treatment regimen we plan to publish in a later study.

Optimization of cell density and LPS concentration for the evaluation of nitric oxide production on BV-2 in a Griess assay

Introduction: Production of nitric oxide (NO) is one of the main responses elicited by a variety of immune cells such as macrophages (e.g. microglia, resident macrophages of brain), during inflammation. Evaluation of NO levels in the inflammatory milieu is considered important to the understanding of the intensity of an immune response; and has been performed using different methods including the Griess assay. To assay NO in culture, an appropriate number of cells are stimulated into an inflammatory phenotype. Common stimuli include lipopolysaccharide (LPS), IFN-γ and TNF-α. However, overt stimulation could cause cell cytotoxicity therefore an ideal concentration of LPS should be used. Objective: To set-up a model of BV-2 cell activation that allows the assay of detectable levels of NO. Optimization of BV-2 microglia cell density and LPS concentrations after stimulation by bacterial lipopolysaccharide (LPS) for the Griess assay is demonstrated in this study. Methods: BV-2 microglia were cultured at different cell densities, and treated with LPS at three concentrations (1, 5, 10 µg/ml). NO production in culture supernatants were then measured at 18, 24, 48 and 72 hours. Moreover, methyl tetrazolium assay (MTT) was also performed to ensure that NO measurement is performed at no-cytotoxic concentrations of LPS. Results and Conclusions: NO production follows a temporal pattern. The density of 25000 cells/ well was the ideal seeding density for NO evaluation in BV-2 cells. BV-2 stimulation by LPS is dose dependent, and NO levels are increased proportional to the LPS concentration up to 1.0µg/ml, whereas the higher LPS concentrations are associated with decreased cell viability may be caused by the high toxic levels of LPS or NO. Although Griess assay has been commonly used by the scientists, however, optimization of its parameters on BV-2 cells will be useful for the experiments which will be performed on this particular cell line. The optimized pattern of Griess assay on BV-2 cells was achieved in this study, hence easier and more practical for the future scientists to perform Griess assay on BV-2 cells.

Staphylococcus aureus Nasal Carriers Among Medical Students in A Medical School

Staphylococcus aureus is usually considered a colonizer but can result in infections under favourable conditions, especially in the healthcare setting. Healthcare workers can be colonized by S. aureus, and may transmit them to patients under their care. We conducted a cross sectional study to determine the prevalence of S. aureus nasal carriers among medical students in Universiti Putra Malaysia (UPM) (from January to June 2011). Our study involved 209 medical students comprising of 111 and 97 preclinical and clinical students respectively. A selfadministered questionnaire was distributed and nasal swabs were collected. Upon identification, the antibiotic susceptibility of the isolates was examined followed by categorical analysis (Chi-square and Fisher’s exact tests) with factors associated with S. aureus nasal carriage. Twenty one (10%) S. aureus strains were isolated from 209 nasal swab samples. 14 isolates were from pre-clinical students while the remaining seven were from clinical students. There was no significant association between gender, ethnicity, health status, skin infection and students’ exposure to hospital environment with S. aureus nasal carriage (p>0.05). Nineteen (90.5%) isolates were resistant to penicillin and there was also no significant association between penicillin resistant and the students’ groups. One (5.3%) isolate was resistant to erythromycin. There was no methicillin-resistant S. aureus isolated in this study.