Gender differences in outcomes of low birth weight and preterm neonates: the male disadvantage.

Various studies conducted worldwide have shown that male neonates have higher rates of mortality and morbidity in the perinatal period compared with females. However, there has been only one study from India on this subject. Therefore, this study was conducted to establish the difference in mortality between males and females among neonates born with two established risk factors of septicaemia--low birth weight (<2.5 kg) and preterm birth (<37 weeks). One hundred and fifty consecutive neonates which were either preterm or had low birth weight were recruited after obtaining informed consent from the parents. Blood culture was done, and the bacterial isolates were identified by standard protocol. Statistically significant association was found between male gender and mortality among culture-positive neonates. Therefore, results of the present study indicate that preterm or low birth weight male neonates have higher likelihood of mortality compared with their female counterparts in the Indian scenario.

First study on detection of cryptic resistance to linezolid among clinical isolates of methicillin resistant Staphylococcus aureus from India.

PURPOSE: Linezolid is an oral antibiotic which is widely used for serious infections caused by Methicillin Resistant Staphylococcus aureus (MRSA). With emergence of vancomycin MIC creep among clinical strains of MRSA, it is essential to know the possible emergence of subclinical resistance against linezolid as well. With this background, we aimed to detect evident (phenotypic) and cryptic (hidden or genotypic) linezolid resistance among MRSA isolates. METHODS: 250 clinical isolates of MRSA were collected and their susceptibility patterns were determined. Every third MRSA isolate was subjected to PCR for domain V of the 23S rRNA for the mutation hotspot in the 746bp segment which harbors the classical mutation for linezolid resistance. Restriction Fragment Length Polymorphism was done to confirm presence of the G2576U mutation. RESULTS: Six isolates (2.4%) were phenotypically resistant to linezolid. Among these six LRSA isolates, 5 demonstrated the G2576U mutation by PCR - RFLP. Cryptic resistance to Linezolid was identified in two isolates among linezolid susceptible isolates. CONCLUSIONS: In the present study, hidden resistance to linezolid was observed in linezolid susceptible clinical isolates. Emergence of resistance against over-the-counter drugs like linezolid is major challenge. Identification of cryptic resistance among patients implies impending resistance to linezolid. Judicious use of antimicrobials, application of strict infection control practices and prescription audit needs to be made mandatory to preserve such drugs.

Development, optimization, standardization, and validation of a simple in-house agar gradient method to determine minimum inhibitory concentration of vancomycin for Staphylococcus aureus.

BACKGROUND: The Clinical and Laboratory Standards Institute recommends reporting minimum inhibitory concentration (MIC) values of vancomycin for Staphylococcus aureus. Commercial MIC strips are expensive, and the traditional broth microdilution method is cumbersome. With this background, we attempted to develop and standardize an in-house agar gradient method to determine MIC values of vancomycin for S. aureus. OBJECTIVES: To develop and validate an in-house vancomycin MIC strip, based on simple agar gradient method for S. aureus as per bioassay development guidelines. MATERIALS AND METHODS: Filter paper gradient strips were made in house and impregnated with varying concentrations of vancomycin to create an antibiotic gradient. During standardization, MICs of ninety clinical strains of S. aureus and ATCC 29213 were tested by the broth microdilution and commercial strip followed by the in-house strip. During the validation stage, MICs of ninety different clinical strains of S. aureus and ATCC 29213 were determined by the in-house strip followed by MIC detection by broth microdilution and commercial strips. A reading of more than ± 1log2 dilution compared with broth microdilution was considered as an outlier. RESULTS: During the initial stage, there were 7/90 outliers in the clinical strains, and no outliers were seen with the ATCC 29213 control strain. Corrective action included increasing precaution during the antibiotic impregnation on the strip. During validation stage, only 4/90 outliers were observed in the clinical strains. The commercial strips had 29/90 among clinical and 15/30 outliers in the control strain during the prevalidation phase. Despite maintaining cold chain during the validation phase, the outliers for commercial strip were 18/90 and 4/30 for clinical and control strains, respectively. CONCLUSION: Reporting vancomycin MIC for S. aureus may be attempted using the in-house method after validating it with a gold standard broth microdilution method and quality control as per protocol.

Changing trends in antimicrobial susceptibility pattern of bacterial isolates in a burn unit.

INTRODUCTION: Emerging antimicrobial resistance in nosocomial bacterial isolates, limits the available treatment options for burn wound infections, among them multi-drug resistant Gram negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA) are major contributors to the increase in morbidity and mortality rates. MATERIAL AND METHODS: A retrospective cross-sectional study was done in the Department of Microbiology, University College of Medical Sciences & Guru Teg Bahadur Hospital, Delhi. A total of 818 wound samples from patients admitted in the burn wards and Intensive Care Units (ICUs) examined between 2010-2014 (5 years period). Pseudomonas aeruginosa was found as the most common isolate (37%) followed by Klebsiella pneumoniae (15%) and Acinetobacter baumanii (12%) among Gram negative organisms while S. aureus (12%) remained the major isolates among Gram positive organisms. A significant decrease in incidence of Gram positive organisms was observed in comparison with previous study. However, resistance to ceftazidime and aminoglycosides were increased significantly in Gram negative organisms. Multi-drug resistant P. aeruginosa (MDR PA) accounted for 15.2%, multi-drug resistant A. baumanii (MDR AB) was prevalent in 13.8% and MRSA in 77.4% of burn wound infections. DISCUSSION AND CONCLUSION: Emerging bacterial drug resistance has both clinical and financial implications for the therapy of infected burn patients. Spectrum of bacterial drug resistance in an institution is important for epidemiological as well as clinical purposes. Rising frequency of MDR strains in burn patients is alarming for clinicians as it downgrades the treatment efficacy.

Revisiting the Utility of Histopathological Examination of Biopsy: A Necessity in Microbiology.

INTRODUCTION: Culture is the gold standard, while potassium hydroxide mount is simplest technique used for diagnosis of fungal pathogens. Histopathological examination is the only definitive means to identify certain uncultivable fungi. AIM: To analyse role of histopathological examination and potassium hydroxide (KOH) mount for diagnosing fungal infections by correlating them with culture. MATERIALS AND METHODS: In this nine year retrospective study, all biopsy specimens submitted for microbiological examination were included. Histopathological examination of biopsies of cases with positive microbiological findings on either KOH mount or culture was carried out. Any discrepancy between histopathology interpretation and microbiology KOH or culture results, taking culture as the gold standard, were noted. STATISTICAL ANALYSIS: Open Epi software was used for statistical analysis. Comparisons between groups were made by using the chi-square test. A p-value < 0.05 was considered statistically significant. Cohen's Kappa coefficient (κ) was calculated as a measure of agreement between different variables. RESULTS: Concurrent pathology specimen could be obtained in 70 samples positive for fungal elements in either KOH or culture. Thirty-two cases were positive for fungi in culture, of which 16 were correctly identified by histopathological examination. Histopathological examination was strongly associated with culture result. KOH mount was in good agreement with positive culture result for yeast. Eleven culture negative but KOH and histopathology positive cases included seven samples with hyphae suggestive of zygomycosis, and two cases of rhinosporidiosis. Allergic mucin was strongly associated with Aspergillus species. KOH mount and detection of allergic mucin on histopathological examination were found to be excellent complementary tools for diagnosing Aspergillus species. Necrosis was highly specific for fungal growth in culture and had good positive predictive value. CONCLUSION: We advocate using histopathology, culture and KOH examination in an integral manner to avoid potential lapses in patient management.

Safety and immunogenicity of Bio Pox™, a live varicella vaccine (Oka strain) in Indian children: A comparative multicentric, randomized phase II/III clinical trial.

Varicella or chickenpox is a highly contagious disease with a high secondary attack rate. Almost 30% of Indian adolescents lack protective antibodies against varicella, emphasizing the need of routine varicella immunization. The Oka VZV is a well-established, safe and efficacious vaccine strain that is highly immunogenic and produces lifelong protective immunity. The present multicentric, open label, randomized, controlled Phase II/III study, compared the Bio Pox™ (indigenous investigational vaccine) with a licensed vaccine, Varivax™ [a][a] Please note that this article refers to the product named VARIVAX as manufactured by Changchun Keygen Biological Products Ltd., China and marketed in India by VHB Life Sciences Limited, Mumbai, and not the product VARIVAX® owned by Merck Sharp & Dohme Corp., Rahway, New Jersey, USA. Merck Sharp & Dohme Corp. have asked us to make clear that the product manufactured by Changchun Keygen Biological Products Ltd. is unrelated to and is not sponsored, endorsed or otherwise authorised by Merck Sharp & Dohme Corp. , for its safety and immunogenicity profile in 252 healthy subjects in the age group of 1-12 y (cohort I: 6-12 years, II:1-6 years) in 3 tertiary medical institutions. Antibodies were measured by VZV Glycoprotein Enzyme Linked Immunoassay (IgG ELISA) kit. Seroconversion percentage in children having pre-vaccination anti VZV IgG titer <10 mIU/mL (< 5 gp ELISA units/mL) were 80% for Bio Pox™ and 77% for Varivax™ (p = 0.692). The seroconversion rate in the group receiving Bio Pox™ was non-inferior to the group that received Varivax™. There were mild local reactions for both the vaccines; none of the patient had fever or required hospitalization or medication. The Bio Pox™ was found to be safe and immunogenic in children against VZV infection.

Disseminated tuberculosis in a newborn infant.

Tuberculosis (TB) remaining as one of the deadliest communicable diseases. Congenital infection by vertical transmission is rare but high neonatal mortality (up to 60%) and morbidity warrant early and accurate diagnosis of newborns suffering from TB. Intrauterine infection of tuberculosis is most commonly caused by haematogenous spread from the mother causing placental seedling. The organisms reach the fetus via the umbilical vein and the primary focus is often in the fetal liver in hematgenous spread. Another route of infection is by direct ingestion or aspiration of infected amniotic fluid if the placental caseous lesion ruptures directly into the amniotic cavity. Transplacental infection occurs late in pregnancy and aspiration from amniotic fluid occurs in the perinatal period. We report here one case of disseminated tuberculosis in a new born infant.

Anti-cysticercus antibody detection in saliva as a potential diagnostic tool for neurocysticercosis.

OBJECTIVES: This study was planned to determine the usefulness of anti-cysticercus IgG antibody detection in saliva for neurocysticercosis (NCC) diagnosis, along with serum C-reactive protein (CRP) level to serve as a surrogate marker. MATERIALS AND METHODS: In this prospective study of 14 months duration, blood and saliva samples were collected from 40 patients suspected to be suffering from NCC and were subjected to anti-cysticercus IgG antibody detection by ELISA. Serum CRP levels were estimated as acute-phase reactant by high sensitivity CRP ELISA. RESULTS: Anti-cysticercus IgG was detected in serum and saliva of 34 and 30 patients, respectively. Cases positive for salivary antibody were positive for serum antibody and their serum CRP level was higher than normal. Cases negative for salivary antibody had low serum CRP levels. Anti-cysticercus IgG detection in saliva was 88.24% sensitive, 100% specific, and had a positive predictive value of 100% and negative predictive value of 60%. Positive salivary anti-cysticercus IgG and high serum CRP level showed a significant association. Difference between CRP levels of patients positive for anti-cysticercus antibody in both serum and saliva, and patients positive for antibody in serum but not saliva was highly significant. CONCLUSIONS: Saliva, being painless and noninvasive, can be used as alternative to serum for NCC diagnosis.

Application of a stool antigen test to evaluate the burden of Helicobacter pylori infection in dyspepsia patients.

Helicobacter pylori (HP) is causally associated with peptic ulcer disease and gastric carcinoma. Determination of the prevalence of HP infection in dyspepsia patients' in particular geographical area is imperative for the appropriate management of dyspepsia. HP antigen detection in stool is a noninvasive diagnostic test of HP infection. This prospective study was conducted to find out the prevalence of HP infection based on stool antigen testing in dyspeptic patients who had also undergone upper gastrointestinal (GI) endoscopy. This study highlights the high prevalence of HP infection in dyspeptic Indian patients, particularly males, and emphasizes the growing importance of the bacterium causing infection among children. We also found HP stool antigen testing to be superior to upper GI endoscopy for detecting HP infection. Hence, we recommend initial testing for HP stool antigen in dyspeptic patients before initiating treatment and before carrying out any invasive procedure such as endoscopy.