Sanjeev Saini

Staphylococcus aureus phage types and their correlation to antibiotic resistance

CONTEXT Staphylococcus aureus is one of the most devastating human pathogen. The organism has a differential ability to spread and cause outbreak of infections. Characterization of these strains is important to control the spread of infection in the hospitals as well as in the community. AIM To identify the currently existing phage groups of Staphylococcus aureus, their prevalence and resistance to antibiotics. MATERIALS AND METHODS Study was undertaken on 252 Staphylococcus aureus strains isolated from clinical samples. Strains were phage typed and their resistance to antibiotics was determined following standard microbiological procedures. STATISTICAL ANALYSIS Chi square test was used to compare the antibiotic susceptibility between methicillin resistant Staph. aureus (MRSA) and methicillin sensitive S. aureus (MSSA) strains. RESULTS Prevalence of MRSA and MSSA strains was found to be 29.36% and 70.65% respectively. Of these 17.56% of MRSA and 40.44% of MSSA strains were community acquired. All the MSSA strains belonging to phage type 81 from the community were sensitive to all the antibiotics tested including clindamycin and were resistant to penicillin. Forty five percent strains of phage group III and 39% of non-typable MRSA strains from the hospital were resistant to multiple antibiotics. CONCLUSION The study revealed that predominant phage group amongst MRSA strains was phage group III and amongst MSSA from the community was phage group NA (phage type 81). MSSA strains isolated from the community differed significantly from hospital strains in their phage type and antibiotic susceptibility. A good correlation was observed between community acquired strains of phage type 81 and sensitivity to gentamycin and clindamycin.

Epidemiology of opportunistic infections and its correlation with CD4 T-lymphocyte counts and plasma viral load among HIV-positive patients at a tertiary care hospital in India.

The study was conducted to find the correlation of CD4 counts and plasma viral load (PVL) with opportunistic infections (OIs) in HIV-positive patients. A total of 43 drug-naive patients enrolled in the study. Absolute CD4 counts and PVL were measured. On the basis of symptoms, sputum, stool, and blood samples were obtained for laboratory tests. Oral swabs were obtained from all the patients. Pneumocystis jiroveci pneumonia was found in 45.2% patients (odds ratio [OR] = 12.8 for CD4 counts ≤100 cells/ mm3 and 8.5 for PVL >4.0 log10 copies/mL). Pulmonary tuberculosis (TB; OR = 8.0 for PVL >4.0 log10 copies/mL) and streptococcal pneumonia (detected only with CD4 counts <50 cells/mm 3 and PVL >4.0 log10 copies/mL) were seen in 41.9% and 12.9% patients, respectively. Among patients with diarrhea, Giardia lamblia was detected in 31% patients (OR = 3.0 for CD4 counts ≤100 cells/mm3 and 4.0 for PVL >4.0 log10 copies/mL) and Cryptosporidium in 17.2% patients (OR = 1.8 for CD4 counts ≤100 cells/mm3 and found only with PVL >4.0 log10 copies/mL). Shigellosis and Clostridium difficile toxin was present in 13.6% patients and 6.8% patients, respectively.

Resistance-Associated Mutations in HIV-1 among Patients Failing First-Line Antiretroviral Therapy:

Thirty-five HIV-1 infected patients showing clinical and/or immunological failure to first line antiretroviral therapy (ART) according to WHO criteria were recruited from the ART center of Lok Nayak Hospital, New Delhi to detect the presence of resistance-mutations in reverse transcriptase (RT) and protease (PR) region of pol gene of HIV-1. Plasma viral load (PVL) was estimated. HIV-1 pol gene region encoding complete protease and reverse transcriptase (codons; 1-232 to 1-242) was reverse transcribed, followed by nested PCR. The PCR product was sequenced and analyzed. Plasma samples from 94.3% of patients with PVL >log10 3.0 c/mL could be amplified and analyzed. Virologic failure was detected in 65.7% of patients according to WHO criteria (PVL >log10 4.0). All patients were found to be infected with subtype C. One or more resistance-mutations were observed among 90.9% of study sequences. Nucleoside reverse transcriptase inhibitor (NRTI) resistance mutations were seen among all patients, with M184V and thymidine analogue mutations (TAM) being most frequently detected (75.6% and 72.7%, respectively). Nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance-mutations were detected in 63.6% of sequences, of which Y181C/I (47.6%), K103N (33.3%) and G190S (28.6%) are the most common. None of the sequences showed major protease inhibitors (PIs) resistance mutation. High prevalence of NRTI and NNRTI drug resistance mutations among the study participants warrants the use of genotypic resistance testing to prevent accumulation of resistance mutations, which would limit future treatment options.

Hepatitis B Infection in Microbiology Laboratory Workers: Prevalence, Vaccination, and Immunity Status

The risk of contracting HBV by health care workers (HCW) is four-times greater than that of general adult population. Studies have demonstrated that vaccine-induced protection persists at least 11 years. High risk groups such as HCWs should be monitored and receive a booster vaccination if their anti-HBsAb levels decrease below 10 mIU/mL. In view of the above this study was undertaken to assess the HBV vaccination of the HCWs and their immunological response. Seventy-two HCWs of the Department of Microbiology, Maulana Azad Medical College, New Delhi, India, were recruited and blood sample was drawn for serological tests (HBSAg, anti-HCV, anti-HBsAb, anti-HBeAb, and anti-HBcAb). Anti-HBs titers of >10 mIU/mL were considered protective. Thirty-four (47.3%) of the participants were completely vaccinated with three doses. 25 (73.5%) of the participants with complete vaccination had protective anti-HBsAb levels as against 8 (53.3%) of those with incomplete vaccination and 9 (39.1%) of those who were not vaccinated at all. One of our participants was acutely infected while 29 participants were susceptible to infection at the time of the study. All HCWs should receive three doses of the vaccine and be monitored for their immune status after every five years. Boosters should be administered to those who become susceptible.

Role of C-reactive protein in HIV infection: a pilot study.

Limited data on acute phase C-reactive protein (CRP) levels in human immunodeficiency virus (HIV) infection exist. The relationship of CRP with HIV was assessed in 119 HIV-positive patients and correlated with CD4 counts and mortality at 1 y. CRP was negatively correlated with CD4 counts with levels of CRP being highest in the group with CD4 counts below 200 cells/microL. It was an indicator of mortality and hence may serve as a useful and inexpensive predictor of HIV disease progression.

Use of surrogate markers to predict the HIV disease stage and time to initiate antiretroviral therapy in developing countries.

CD4 counting is the standard method for determining eligibility for antiretroviral therapy (ART) and HIV disease progression, but it is not widely available in developing countries. The aim of this study was to correlate the levels of β-2 microglobulin and total lymphocyte count (TLC) with CD4 counts for monitoring disease progression and identify patients who require ART. The authors measured CD4 T-cell counts, TLC, and β-2 microglobulin levels in 119 HIV seropositive patients. There was a significant negative correlation between CD4 counts and β-2 microglobulin levels and significant positive correlation between TLC and CD4 counts. Taking a TLC cutoff of ≤ 1600 and β-2 microglobulin levels ≥ 3.5 mg/l, the authors could identify 90.4% of patients with CD4 count ≤ 200 cells/µl. These assays may allow reduction in the annual number of CD4 cell evaluation and the cost associated with monitoring the immune status of HIV-positive patients.

CORRELATION BETWEEN BASELINE CD4 + T-LYMPHOCYTE COUNT AND PLASMA VIRAL LOAD IN AIDS PATIENTS AND THEIR EARLY CLINICAL AND IMMUNOLOGICAL RESPONSE TO HAART: A PRELIMINARY STUDY

The aim of this study was to determine the clinical, immunological and virological status of newly diagnosed AIDS cases and to monitor their clinical and immunological response to HAART after a minimum period of three months. Forty three drug naive AIDS patients were enrolled. The most common presenting complaints were weight loss (74.4%), cough (72.1%) and diarrhoea (67.4%). Mean baseline CD4 cell count was 112 +/- 60 cells/microL and mean baseline plasma viral load of 31 patients studied was 192,686 copies/mL. Baseline plasma viral load was higher among patients with lower baseline CD4 cell count. During follow-up, 80.8% patients showed clinical improvement, while a CD4 cell count increased by > or =50 cells/microL in 84.6% cases. Mean CD4 cell count increased from 126 +/- 16.6 cells/microL at baseline to 278 +/- 196.7 cells/microL.

Utility of Serum Neopterin and Serum IL-2 Receptor Levels to Predict Absolute CD4 T Lymphocyte Count in HIV Infected Cases.

A prospective study was carried out to evaluate the efficacy of serum neopterin and soluble IL-2 receptor (sIL-2R) concentrations in comparison to CD4 count to study the progression of HIV disease and monitor response to ART in HIV cases. One hundred newly diagnosed HIV seropositive subjects were recruited. CD4 counts were determined by FACS system. Serum neopterin and sIL-2R levels were measured using enzyme immunoassay. In our study, levels of neopterin and sIL-2R were significantly higher in subjects with CD4 <200 cells/μL (with S. neopterin levels of >25.1 nmol/L and sIL-2R levels of >47.1 pM as cutoff values for CD4 <200 cells/μL) compared to those in subjects with CD4 >200 cells/μL at baseline which indicate that these markers can be utilized for initiation of ART in HIV cases. The levels of these markers decreased significantly after initiation of ART. In patients with CD4 >200 cells/μL, these markers are helpful in predicting disease progression.

Use of total lymphocyte count to predict absolute CD4 count in HIV-seropositive cases.

We conducted an observational study to assess the use of total lymphocyte counts (TLC) alone and along with hemoglobin (Hb) as a predictor of CD4 count. A total of 103 antiretroviral therapy (ART)-naive HIV-1-infected patients were enrolled and divided in 2 groups (with CD4 count <200 cells/mm3 and CD4 count ≥200 cells/mm3). The TLC and Hb were performed by automatic full digital cell counter. CD4 count was determined by flow cytometry. Among the World Health Organization (WHO) clinical stages 2 and 3, in the cases with CD4 count <200 cells/mm3, 70.4% cases had TLC ≤1200 cells/mm 3, whereas 63% cases had TLC ≤1200 cells/mm3 + Hb ≤12 g/dL. In the cases with CD4 count >200 cells/mm3, 2% cases had TLC ≤1200 cells/mm3, whereas adding Hb ≤12 g/dL with TLC ≤1200 cells/mm3, none of the cases would require initiation of ART. TLC + Hb can be used to treat all HIV-infected patients with WHO stages 2 and 3 who have a TLC <1200 cells/mm3 + Hb ≤12 g/dL and to limit CD4 counts to patients who are symptomatic but have TLC + Hb values other than TLC <1200 cells/mm3 + Hb ≤12 g/dL.

Profile of direct walk-in and referred clients attending Integrated Counselling and Testing Centre

The HIV pandemic has had a profound impact on the health and economic conditions of individuals, and people living with HIV/AIDS are faced with the task of maintaining optimal health status despite an increasing insult to their immune status. The aim of the present study was to study the profile of direct walk-in and referred patients attending the Integrated Counselling and Testing Centre (ICTC) of a tertiary care hospital, which may provide important clues to understanding the epidemiology of the disease in a particular region. The study included all the attendees of the ICTC referred from the hospital or direct walk-in from January 2007 to December 2007. Three rapid HIV tests were used and the samples showing positive results in all the three tests were declared HIV positive. The results were analysed to correlate between HIV positivity, age, sex, route of transmission and direct walk-in/referred patients. A low proportion of ICTC attendees (27%) in our study were direct walk-ins. As regards HIV positivity, 312 (8.3%) out of 2440 males and 164 (4.3%) out of 1315 females were HIV positive. Among the referred HIV-positive patients 162 were males and 62 females, whereas among the direct walk-in HIV-positive patients, 150 were males and 102 females. Integrated counselling and testing is now seen as a key entry point for HIV prevention. In addition to scaling up ICTC services, it is also important to raise awareness by aggressive health education programmes and integration of ICTC into various community organizations.