Group B Rotavirus Infections in Mymensingh, 2015.

Rotaviruses are the most important etiological agents of severe diarrheal illness in infants, children, and adults throughout the world. Group A rotavirus causes approximately 40% of hospitalization for diarrhea among under 5 years children. The prevalence of Group B rotaviruses is not as high as that of Group A. ICDDRB, in 2008 reported Group B rotaviruses as 2.4%. Polyacrylamide gel electrophoresis (PAGE) and silver staining was applied to detect rotavirus dsRNA from acute diarrheic stool of 364 hospitalized adult patients with mild to severe diarrhea. The study was conducted in Mymensingh district, Bangladesh from January 2013 to December 2014. Among 364 stool specimens tested 14(3.9%) were positive in adult by PAGE. Males were slightly higher than females and infection rate was more in winter. PAGE technique could be applied as an excellent method for studying different groups of rotavirus including Group B rotaviruses.

Electrophoretic Patterns of Human Rotavirus Strain Prevailing Among Children.

Rotavirus gastroenteritis is a major cause of severe dehydrating diarrhea in children worldwide. Group A rotavirus causes approximately 40% of hospitalization for diarrhea among under 5 years children. Polyacrylamide gel electrophoresis (PAGE) and silver staining was applied to detect rotavirus dsRNA from acute diarrheic stool of 776 hospitalized children below five years. The study was conducted in Mymensingh district, Bangladesh from January 2013 to December 2014. Among 776 stool specimens tested 368(47.4%) were positive by PAGE. Among 368 positive 341(92.5%) showed clearly stained electrophoretic patterns of viral RNA which enabled their classification into different electropherotypes. The rate of infection was highest in children of 7-12 months of age and infection rate was more in winter. RNA profiles of the analyzed specimens, 164/341 (48%) were long and 177/341 (52%) were short patterns. Mixed electropherotypes (2%) among 368 were also detected. Electropherotyping technique could be an applied excellent method for studying genomic variation, tracing mixed infections, detecting atypical rotaviruses.

Molecular-Characterization of Methicillin-Resistance Staphylococcus aureus (MRSA) from Different Tertiary Care Hospitals in Bangladesh.

Infections caused by Staphylococcus aureus were treated by methicillin, but about 95% of S. aureus has been resistance to methicillin, both in the community and hospitals and are increasing day by day. MRSA produces altered penicillin binding protein, PBP2a, due to the expression of mecA gene. Some strains of both the MRSA and MSSA carry PVL gene. This cross sectional observational study was conducted to detect the molecular-characterization of methicillin resistant Staphylococcus aureus (MRSA) and carried out in the Department of Microbiology, Mymensingh Medical College from July 2014 to December 2015. Clinical samples for this study were wound swab, pus, exudates from diabetic ulcer and burn ulcer, aural swab, blood and urine which were collected from three tertiary care hospitals such as from MMCH, BIRDEM hospital and SSMCH. Standard microbiological procedure & biochemical tests were carried out to detect S. aureus. Oxacillin disk diffusion method (ODDM) was done by Kirby-Bauer disk diffusion method. Out of a total 109 culture positive samples 69 isolates of S. aureus were selected for the study. Among the 69 isolates 33, 27 and 09 were from MMCH, BIRDEM hospital and SSMCH respectively. Among the 69 isolates, 17(24.6%) and 52(75.3%) were distinguished as MRSA and MSSA respectively by ODDM. In contrast, detection of presence and absence of mecA gene by PCR identified 20(28.9%) and 49(71.01%) isolates as MRSA and MSSA respectively. Multiplex PCR was performed by standard protocol with specific primers for detection of 16S rRNA gene for Staphylococcus, nuc gene for Staphylococcus aureus, mecA gene for MRSA, PVL gene as a virulence factor and ACME-arc gene for worldwide spreading USA 300 MRSA clone. The PVL gene were detected in 3 out of 20 MRSA (15%) and 19 out of 49 MSSA (38.7%) and the ACME- arc gene was not found in any isolates. All of the S. aureus (MRSA and MSSA) isolates were sensitive to Vancomycin and Gentamicin. All MRSA isolates (100%) showed resistance to Penicillin and Oxacillin. Of the MRSA isolates about 88.2% were resistance to Ceftazidime, 64.7% were resistance to Erythromycin and Ciprofloxacin, 11.7% were resistance to Tetracycline. Among the MSSA isolates 94.2% were resistance to Penicillin and 9.6% resistance to Ciprofloxacin. The MSSA were less resistance for non-beta lactam drugs than MRSA.

Evaluation of PCR with culture for the diagnosis of pulmonary tuberculosis.

Tuberculosis (TB) is a major public health problem in most developing countries. The present study was carried out among 100 clinically suspected pulmonary TB patients. One hundred sputum specimens were collected one from each of the suspects attending DOT'S corner of Mymensingh Medical College Hospital, Mymensingh, Bangladesh. The aim of the study was to evaluate the sensitivity and specificity of a polymerase chain reaction (PCR) based method detecting IS6110 sequence present in all Mycobacterium tuberculosis strains using sputum samples in comparison to culture on Lowenstein-Jensen mediums. The PCR was done using primers mtb1 & mtb2 which commonly target an insertion sequence of the organism (IS6110). Out of 100 samples, 18 (18%) showed PCR positive, whereas culture in Lowenstein-Jensen media were positive in 19(19%). In PCR 1 was false negative but none was false positive. In present study, sensitivity and specificity of PCR found 94.74% and 100% respectively. Analyzing the findings of the present study, it can be concluded that the PCR technique is a rapid and alternative method of culture on Lowenstein-Jensen medium for the diagnosis of pulmonary tuberculosis. In the present study, only presence or absence of M. tuberculosis was determined.

Comparison between ICT and PCR for diagnosis of Chlamydia trachomatis.

Chlamydia trachomatis is an obligate intracellular gram-negative bacterium which is the most prevalent cause of bacterial sexually transmitted infections (STI). The present study was carried to diagnose genital Chlamydia trachomatis infection among women of reproductive age, attending Mymensingh Medical College Hospital, during July 2009 to June 2010 by Immunochromatographic test (ICT) and Polymerase chain reaction (PCR). A total of 70 females were included in this study. Out of 70 cases 56 were symptomatic and 14 asymptomatic. Endocervical swabs were collected from each of the cases and examined by Immunochromatographic test (ICT) for antigen detection and Polymerase chain reaction (PCR) for detection of endogenous plasmid-based nucleic acid. A total 29(41.4%) of the cases were found positive for C. trachomatis either by ICT or PCR. Of the 56 symptomatic cases, 19(33.9%) were found ICT positive and 17(30.4%) were PCR positive. Among 14 asymptomatic females, 2(14.3%) were ICT positive and none were PCR positive. Though PCR is highly sensitive but a total of twelve cases were found ICT positive but PCR negative. It may be due to presence of plasmid deficient strain of C trachomatis which could be amplified by ompA based (Chromosomal gene) multiplex PCR.

Species distribution of coagulase negative staphylococci isolated from different clinical specimens.

Staphylococci are Gram positive, non motile, asporogenous bacteria that characteristically divide in more than one plane to form irregular cluster. Species are classified as coagulase-positive Staphylococcus aureus and coagulase-negative staphylococci. Coagulase-negative staphylococci (CoNS) are reported to be the third causative agent of nosocomial infections and the most frequent cause of nosocomial bloodstream infections. Strains of CoNS those are resistant to methicillin referred to as Methicillin Resistant Coagulase Negative Staphylococci (MRCoNS). Now a days, MRCoNS has been increasing as a serious nosocomial pathogen having the property of multi drug resistance. The present study was conducted to see the species distribution, antibiotic resistance patterns and some virulence factors of CoNS isolated from different clinical specimens. This cross sectional descriptive study was carried out in the Department of Microbiology, Mymensingh Medical College during the period from July 2009 to May 2011. A total of 300 clinical specimens were collected for this study of which 240 were found culture positive as single isolate. Among them 110 were from surgical wound, 80 from pus of skin infections, 30 from burn ulcer exudates and 20 from diabetic ulcer exudates. A total of 80 strains of CoNS were isolated from them. Besides CoNS other isolated bacteria were S. aureus, Pseudomonas spp and Escherichia coli. The CoNS were initially detected by coagulase test. All the strains that were either slide or tube coagulase negative were further identified by different biochemical tests using a commercial kit HiStaph™ Identification Kit (HiMedia Laboratories Ltd) which comprise a set of 12 standard biochemical tests. A total of 16 species were identified. These were S. epidermidis, S. saprophyticus, S. caprae, S. haemolyticus, S. simulans, S. xylosus, S. hyicus, S. hominis, S. warneri, S. auricularis, S. lugdunensis, S. felis, S. capitis, S. chromogenes, S. carnosus and S. gallinarum. Of them S. epidermidis was the most prevalent (17%) followed by S. saprophyticus (15%), S. caprae (11%), S. haemolyticus (9%).