Deepti Rawat

Extended-spectrum ß-lactamases in gram negative bacteria

Extended-spectrum β-lactamases (ESBLs) are a group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that are posing a major therapeutic challenge today in the treatment of hospitalized and community-based patients. Infections due to ESBL producers range from uncomplicated urinary tract infections to life-threatening sepsis. Derived from the older TEM is derived from Temoniera, a patient from whom the strain was first isolated in Greece. β-lactamases, these enzymes share the ability to hydrolyze third-generation cephalosporins and aztreonam and yet are inhibited by clavulanic acid. In addition, ESBL-producing organisms exhibit co-resistance to many other classes of antibiotics, resulting in limitation of therapeutic option. Because of inoculum effect and substrate specificity, their detection is also a major challenge. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) provide guidelines for the detection of ESBLs in Klebsiella pneumoniae, K. oxytoca, Escherichia coli and Proteus mirabilis. In common to all ESBL-detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic-resistance mechanisms in the face of the introduction of new antimicrobial agents. Thus there is need for efficient infection-control practices for containment of outbreaks; and intervention strategies, e.g., antibiotic rotation to reduce further selection and spread of these increasingly resistant pathogens.

A Study on the Perinatal Transmission of the Hepatitis B Virus

The purpose of this study was to determine the age wise prevalence of Hepatitis B virus (HBV) in children under five years and to analyze the relative importance of horizontal or vertical transmission. This study included 400 children in the age group of less than five years attending the outpatient department of pediatrics with minor complaints. History of HBV immunization was taken as the exclusion criteria. All the samples were tested for Hepatitis B surface antigen (HBsAg) and anti HBs using commercial ELISA kits. Liver function tests were performed on all the HBsAg positive patients. Hepatits B nucleocapsid antigen (HBeAg) was detected in few HBsAg positive mothers. Overall HBsAg positivity in children below five years was 2.25%. There was no statistically significant difference in HBsAg positivity in the different age groups by chi square test. HBsAg positivity in mothers was 4.25%. However only in three cases the pair of mother and child were both positive for HBsAg. The mean anti HBs positivity in children was 23.75%. There was no statistically significant difference in the anti HBs positivity in different age groups of children. The observation that there is no statistically significant difference in the prevalence of HBV infection (HBsAg and HBs) amongst different age groups of children below five years signifies that a large proportion of HBV infection in children of this age is acquired via vertical transmission. It is also indicated that this mode of disease transmission is responsible for the majority of chronic carriers. Universal immunization of all infants is desirable to decrease the carrier pool and it is inferred from the present study that Hepatitis B immunization should begin at birth to have greater impact.

Rapid Tests versus ELISA for Screening of HIV Infection: Our Experience from a Voluntary Counselling and Testing Facility of a Tertiary Care Centre in North India

Early and accurate diagnosis of human immunodeficiency virus (HIV) infection is essential for timely identification of patients needing antiretroviral therapy and for instituting HIV prevention strategies. The primary methodology for HIV testing has shifted from enzyme linked immunosorbent assay (ELISA) to rapid diagnostic tests (RDTs) in recent years, especially in resource limited settings. However, the diagnostic performance of RDTs is a matter of concern. In the present study the performance of an RDT being used as the initial test in serial testing based algorithm for HIV diagnosis was compared with ELISA. Seven hundred and eighty-seven sera, tested at the voluntary counselling and testing facility employing a serial testing algorithm (based on SD Bioline HIV-1/2 3.0 as the first test), were subsequently tested with Microlisa-HIV for anti-HIV antibodies. The first test missed 9 HIV reactive samples and also registered 5 false positives. The sensitivity, specificity, and negative and positive predictive values of the first test were 77.5%, 99.3%, and 98.8% and 86.1%, respectively, taking ELISA as the standard test. Our study highlights that RDTs fare poorly compared to ELISA as screening assays and that reactive results by RDTs need to be confirmed by western blot for a positive serodiagnosis of HIV infection.

Rising trend of antimicrobial resistance among Neisseria gonorrhoeae isolates and the emergence of N. gonorrhoeae isolate with decreased susceptibility to ceftriaxone.

Context: Gonorrhoea is one of the most common sexually transmitted infections (STI) in developing countries and is a global health problem. Aims: To analyze the trend of antimicrobial susceptibility of Neisseria gonorrhoeae isolates over the years, in a tertiary care hospital of North India. Settings and Design: The study population comprised males with urethritis and females with endocervicitis attending STI clinic of our hospital. Materials and Methods: In our STI laboratory, all gonococcal isolates are subjected to antimicrobial susceptibility testing by disc diffusion method as per CLSI guidelines. β-lactamase production is determined by chromogenic cephalosporin test. Minimum Inhibitory Concentration (MIC) for ceftriaxone is determined by E-test. Statistical Analysis Used: Data were expressed as percentages. The differences in percentages were tested for statistical significance by using χ2 test and P values were determined. Results: The percentage of penicillinase producing N. gonorrhoeae (PPNG) increased from 8% in 1995-96 to 20% in 2004-05 and 88% in 2011-2013. Quinolone-resistant N. gonorrhoeae (QRNG) showed a significant increase from 12% in 1995-96 to 98.3% in 2004-05, while 84% isolates were found to be QRNG by 2011-2013. In January 2013 we detected our first gonococcal isolate with decreased susceptibility to third-generation cephalosporins; Ceftriaxone, Cefixime and Cefpodoxime (MIC for ceftriaxone = 0.19 μg/ml). Conclusions: The results of our study highlighted an alarming increase in the percentage of PPNG and QRNG strains over the years. Emergence of N. gonorrhoeae isolates with decreased susceptibility to third-generation cephalosporins is a cause of concern and thus emphasises the importance of antimicrobial susceptibility testing.

Evaluation of SD BIOLINE Syphilis 3.0 for rapid diagnosis of syphilis: Report from a regional sexually transmitted infection reference laboratory in North India

Background: Serology is considered the mainstay of syphilis diagnosis. The limitations of the traditional serological methods and the advent and availability of novel immunochromatographic assays have led to the widespread application of rapid point-of-care procedures as screening tools for syphilis. However, these tests have not been extensively evaluated. This study was designed to evaluate the performance of a rapid syphilis diagnostic test known as SD BIOLINE Syphilis 3.0 (SD Biostandard Diagnostics Private Limited, Gurgaon, Haryana, India). Materials and Methods: A panel comprising of 50 venereal disease research laboratory reactive and 50 nonreactive sera was tested using SD BIOLINE Syphilis 3.0. The performance of the test was evaluated using IMMUTREP Treponema pallidum hemagglutination assay (TPHA) (OMEGA Diagnostics Limited, Scotland, United Kingdom) as the reference standard and sensitivity, specificity, and negative and positive predictive values were calculated. Results: The sensitivity, specificity, and positive and negative predictive values of SD BIOLINE Syphilis 3.0 were 92.86% (confidence interval of 95%: 80.52–98.50%), 98.28% (90.76-99.96%), 97.50% (86.84–99.94%), and 95.00% (86.08–98.96%), respectively, compared to TPHA as the gold standard. Conclusion: Keeping in view the high sensitivity and specificity of SD BIOLINE Syphilis 3.0, we conclude that the test can be used as a tool for rapid on-site diagnosis of syphilis and as an alternative to TPHA for detection of antibodies to Treponema pallidum.

A case of extended spectrum beta-lactamase producing Salmonella enterica serotype paratyphi A from India

Enteric fever caused by Salmonella enterica is a systemic infection with high rates of morbidity and mortality. Increasing antibiotic resistance in S. enterica has led to shift in the choice of antibiotics used against this organism from chloramphenicol and ampicillin to trimethoprim-sulfamethoxazole, fluoroquinolones, and extended-spectrum cephalosporins. Resistance to cephalosporins, due to the production of extended-spectrum beta-lactamases (ESBLs), is the cause of serious concern worldwide. So far, these enzymes have been detected in many species of the family Enterobacteriaceae including different serotypes of S. enterica. To the best of our knowledge, however, ESBL production in Salmonella Paratyphi A has not yet been reported from India. We present here a case of ESBL producing Salmonella Paratyphi A from India. This is a worrisome finding with grave clinical implications, since the dissemination of this resistance trait would further limit the therapeutic options available for the treatment of enteric fever.

HIV/AIDS Awareness among VCT Clients: A Cross-Sectional Study from Delhi, India

The contribution of India to the global burden of HIV/AIDS is significant. A major barrier that the country has faced in its battle against this disease is the inadequate and inaccurate information about it among the population. The present analysis explores the knowledge about HIV/AIDS among clients attending a voluntary counselling and testing (VCT) facility in India. Two hundred clients attending the VCT facility were assessed in this regard using a structured predesigned questionnaire. Sixty-three (31.5%) of the respondents had never heard of HIV/AIDS. In comparison to males, a significantly higher number of females had not heard about the disease (P < 0.01). Lower levels of education of participants were found to be significantly associated with the response of not having heard of HIV/AIDS (P < 0.01) as was an occupation status of being an unemployed man/housewife (P = 0.002). For the 137 (68.5%) respondents who had heard about HIV/AIDS, television was the source of information in 130 (94.9%) followed by posters in 93 (67.9%) and newspapers in 88 (64.2%). While the knowledge about HIV transmission and prevention was good, the extent of misconceptions was high (61.8%). Our study highlights the strong need to raise the levels of HIV awareness among Indian population.

Correlation of CD4 T Cell Count and Plasma Viral Load with Reproductive Tract Infections/Sexually Transmitted Infections in HIV Infected Females

BACKGROUND Sexually transmitted infections (STIs) plays a major role in the spread of Human immunodeficiency virus (HIV) due to common route of transmission. These infections display an epidemiological synergy with HIV. AIM The aim of this study was to analyse the correlation of CD4 T lymphocyte cell count, HIV-1 plasma viral load with Reproductive tract infections/Sexually transmitted infections (RTIs/STIs) in HIV infected females. MATERIALS AND METHODS The study included 60 HIV infected females. An informed consent was taken from all the study subjects. Relevant specimens (genital specimen and blood) were collected for laboratory diagnosis of various RTIs/STIs, CD4 cell count and plasma viral load estimation. RESULTS Mean CD4 count of females with bacterial vaginosis, vaginal candidiasis, trichomoniasis, syphilis and herpes simplex infection were lower as compared to other HIV infected cases and mean plasma viral load of bacterial vaginosis, vaginal candidiasis, trichomoniasis and syphilis were higher as compared to other HIV infected cases but this difference was not statistically significant. CONCLUSION This study highlights the importance of routine screening for STIs/RTIs of all the HIV infected females for RTIs/STIs irrespective of CD4 cell count and plasma viral load.

A comparative analysis of polymerase chain reaction and direct fluorescent antibody test for diagnosis of genital herpes

Objective: To compare laboratory tests that can simultaneously detect and type herpes simplex virus (HSV) directly from the genital ulcer specimens in clinically suspected cases of genital herpes. Materials and Methods: A study was conducted over 10 months and 44 adult male and female patients clinically suspected with genital herpes were recruited. Genital ulcer swab specimens were subjected to glycoprotein-G gene-based conventional polymerase chain reaction (PCR) and commercially available direct fluorescent antibody (DFA) test and the results were compared. Results: PCR for HSV was positive in 82% (36/44) cases. DFA was positive in 68.2% (30/44) cases. There was 100% agreement between HSV types detected by DFA and PCR. The strength of agreement between the results was better in primary genital herpes than recurrent cases. Conclusion: PCR was found to be better in the detection of HSV in recurrent genital herpes patients. It is a better modality, especially when genital herpes clinically presents with ulcerative or crusted lesions, and is also a cheaper alternative as compared to DFA.

Evaluation of Baseline CD4+ T Cell Counts and ART Requirement in Newly Diagnosed HIV Seropositive Individuals in a Tertiary Care Hospital of Northern India.

INTRODUCTION Antiretroviral Therapy (ART) has changed the outlook of Human Immune-deficiency Virus (HIV)/Acquired Immuno Deficiency Syndrome (AIDS) patients worldwide. AIM To analyse the trends in baseline CD4+ T cell counts and ART requirements in newly diagnosed HIV seropositive individuals in a Tertiary care hospital of Northern India. MATERIALS AND METHODS Out of 1263 HIV seropositive clients identified from January 2012 to June 2014, the baseline CD4+ T cell counts of only those 470 clients were analysed, who registered at the linked ART centre. RESULTS The mean baseline CD4+ count of the study group was 249.77±216.0cells/mm3 and that of male and female were 300.31±240.47cells/mm3 and 232.38±204.25cells/mm3 respectively. A total of 259 of 334 (77.54%) HIV reactive males, 83 of 130 (63.85%) HIV reactive females and overall 348 of 470 (74.04%) required antiretroviral treatment on enrolment. CONCLUSION In the present study, about three-fourth of newly diagnosed HIV positive Indian patients required initiation of ART at registration. The relatively low baseline CD4+ T cell counts in this population highlights the need for timely baseline CD4+ counts testing of HIV positive patients and the urgency of initiating treatment in HIV reactive individuals in Indian health care settings.