Nabaraj Adhikari

Multidrug resistant Vibrio cholerae O1 from clinical and environmental samples in Kathmandu city

BackgroundCholera, an infectious disease caused by Vibrio cholerae, is a major public health problem and is a particularly burden in developing countries including Nepal. Although the recent worldwide outbreaks of cholera have been due to V. cholerae El Tor, the classical biotypes are still predominant in Nepal. Serogroup O1 of the V. cholerae classical biotype was the primary cause of a cholera outbreak in Kathmandu in 2012. Thus, this study was designed to know serotypes and biotypes of V. cholerae strains causing recent outbreak with reference to drug resistant patterns. Moreover, we also report the toxigenic strains of V. cholerae from both environmental and clinical specimens by detecting the ctx gene.MethodsTwenty four V. cholerae (n = 22 from stool samples and n = 2 from water samples) isolated in this study were subjected to Serotyping and biotyping following the standard protocols as described previously. All of the isolates were tested for antimicrobial susceptibility patterns using the modified Kirby-Bauer disk diffusion method as recommended by CLSI guidelines. The screening of the ctx genes (ctxA2-B gene) were performed by PCR method using a pair of primers; C2F (5′-AGGTGTAAAATTCCTTGACGA-3′) and C2R (5′-TCCTCAGGGTATCCTTCATC-3′) to identify the toxigenic strains of V. cholerae.ResultsAmong twenty four V. cholerae isolates, 91.7% were clinical and 8.3% were from water samples. Higher rate of V. cholerae infection was found among adults of aged group 20–30 years. All isolates were serogroups O1 of the V. cholerae classical biotype and sub serotype, Ogawa. All isolates were resistant to ampicillin, nalidixic acid and cotrimoxazole. 90.9% were resistant to erythromycin however, tetracycline was found to be the most effective drug for the isolates. All isolates were multidrug resistant (MDR) and possessed a ctx gene of approximately 400 base pairs indicating the toxigenic strains.ConclusionHundred percent strains of V. cholerae were MDR possessing a ctx gene. It suggests that toxigenic strains be identified and proper antibiotic susceptibility testing be conducted. This will allow effective empirical therapy to be used to treat and control cholera.

Bacterial meningitis in children under 15 years of age in Nepal.

BackgroundBacterial meningitis in children is a life-threatening problem resulting in severe morbidity and mortality. For the prompt initiation of antibacterial therapy, rapid and reliable diagnostic methods are of utmost importance. Therefore, this study was designed to find out the rate of bacterial pathogens of meningitis from suspected cases by performing conventional methods and latex agglutination.MethodsA descriptive type of study was carried out from May 2012 to April 2013. Cerebrospinal fluid (CSF) specimens from 252 suspected cases of meningitis were subjected for Gram staining, bacterial culture and latex agglutination test. The identification of growth of bacteria was done following standard microbiological methods recommended by American Society for Microbiology. Antibiotic sensitivity testing was done by modified Kirby-Bauer disk diffusion method.ResultsFrom the total 252 suspected cases, 7.2 % bacterial meningitis was revealed by Gram staining and culture methods whereas latex agglutination method detected 5.6 %. Gram-negative organisms contributed the majority of the cases (72.2 %) with Haemophilus influenzae as the leading pathogen for meningitis. Overall, 33.3 % mortality rate was found.ConclusionsIn conclusion, a significant rate of bacterial meningitis was found in this study prompting concern for national wide surveillance.

Status of inducible clindamycin resistance among macrolide resistant Staphylococcus aureus

Clindamycin has long been an option for treating both methicillin sensitive Staphylococcus aureus (MSSA) and methicillin resistant S. aureus (MRSA) infections. So, it is utmost important to perform the susceptibility test for erythromycin and clindamycin. And, there is concern on use of this antibiotic in the presence of erythromycin resistance because of the possibility of induction of cross-resistance among members of macrolide, lincosamide and streptogramin B (MLSB) group. During August 2011 to May 2012, a total of 207 isolates of S. aureus were isolated and among which 29.47% (61) isolates were confirmed as MRSA by cefoxitin (30 µg) disc. All the isolates were further processed for MLSB resistance test by double disc diffusion test of erythromycin (2 µg) and clindamycin (15 µg) at a distance of 15 and 22 mm between them. This study result show 12.56% (26) and 14.49% (30) of inducible macrolide-lincosamide-streptogramin B phenotype (iMLSB) resistance type at 22 and 15 mm disc distance, respectively, showing 15 mm disc distance is potential than 22 mm and 17.39% (36) of cMLSB resistance type. Similarly, both iMLSB and cMLSB are greater in MRSA than MSSA and constitutes 18.05 (11) and 36.06% (22), respectively. Thus, this study concludes that D-test should be used as a mandatory method and is more potential in 15 mm disc apart. Key words: Staphylococcus aureus, methicillin resistant S. aureus (MRSA), methicillin sensitive S. aureus (MSSA), inducible macrolide-lincosamide-streptogramin B phenotype (iMLSB), cMLSB, D-test.

Sero-prevalence of Japanese encephalitis (JE) among Nepalese children.

Background: Japanese encephalitis (JE) is one of the major public health problems particularly in the T erai regions of Nepal. Children upto the age of 15 years are more susceptible for JE. The present study was conducted to aim the sero - prevalence of JE among children of Nepal. Methods: The samples were collected and processed at National Public Health Laboratory (NPHL). In this study, children of age upto 15 years defined with Acute Encephalit is Syndrome (AES) were studied. A total 1009 samples, were collected and tested by MAC ELISA technique for the detection of Anti JEV - IgM. Results: From the processed samples, 107 (10.61%) were found positive for Anti JEV - IgM. Among