Immunocytochemical detection of raf kinase inhibitor protein and human papillomavirus profiling of normal and abnormal cervical ThinPrep samples

OBJECTIVES

This study investigates the potential value of Raf kinase inhibitor protein (RKIP) as a marker of normal squamous cells in ThinPrep slides. RKIP was evaluated for its ability to distinguish between normal and abnormal cervical samples in the context of human papillomavirus (HPV) infections.

STUDY DESIGN

A total of 316 ThinPrep samples were taken from women with normal and abnormal cervices. ThinPrep slides were Papanicolaou stained and reported. Residual samples were used for RKIP immunostaining and HPV PCR-based sequencing.

RESULTS

RKIP expression was seen in both nuclei and cytoplasm in 83.7% of samples. RKIP expression was highest (84.6%) in samples with a diagnosis of high-grade squamous intraepithelial lesion (HSIL) or worse; expression was lower in low-grade squamous intraepithelial lesions (73%) and was lowest in samples with normal cytology (p = 0.0023). A total of 74% of HPV-infected ThinPrep samples were immunopositive, and 67% of samples that did not harbor HPV were also immunopositive (p = 0.414). Sensitivity and specificity of RKIP were 84.6 and 34.6%, respectively, for the detection of samples with HSIL or worse.

CONCLUSIONS

This study showed that RKIP expression may be of some value as a marker for abnormal cervical cells. Combined RKIP expression and HPV testing could improve the identification of samples with abnormal cytology.

Viral load of human papillomavirus in women with normal and abnormal cervical cytology in Kuwait

INTRODUCTION

Human papillomaviruses (HPV) are the most commonly known sexually transmitted agents. Almost all cases of cervical cancer are caused by persistent infection. This study was conducted to ascertain whether there is a difference in HPV load in cervical samples with normal and abnormal cervical cytology reports in Kuwait.

METHODOLOGY

HPV-positive abnormal ThinPrep samples (n = 206) and normal ThinPrep samples (n = 120) were taken from women attending gynecology clinics. Real-time PCR was used to measure the viral load for all HPV genotypes.

RESULTS

The median normalized viral load in samples with normal and abnormal cytology reports was 0.86 × 10-7 and 4.66 × 10-7, respectively (p = 0.001). Median normalized viral load of high-risk (HR), intermediate-risk (IR) and low-risk (LR) HPV was 4.04 × 10-7, 0.71 × 10-7 and 2.38 × 10-7, respectively, (p = 0.002).

CONCLUSIONS

The findings suggest that, in the absence of a proper screening programme in Kuwait, quantification of HPV viral load could be considered as a surrogate virology test to identify women with abnormal cytology. Further population-based prospective studies are needed to include more women with high-grade and invasive carcinoma reports.

THE SIGNIFICANCE OF EPIDERMAL GROWTH FACTOR RECEPTOR AND SURVIVIN EXPRESSION IN BLADDER CANCER TISSUE AND URINE CYTOLOGY OF PATIENTS WITH TRANSITIONAL CELL CARCINOMA OF THE URINARY BLADDER

OBJECTIVE

To assess whether epidermal growth factor receptor (EGFR) and survivin immunostaining of tumour cells in urinary cytology and tissue of patients with bladder cancer has a prognostic significance.

DESIGN

Prospective study

SETTING

Department of Surgery (Division of Urology), Mubarak Al-Kabeer Teaching Hospital and Faculty of Medicine, Kuwait University, Kuwait

SUBJECTS

Urine cytology smears obtainedpriorto cystoscopy in patients with transitional cell carcinoma (TCC) of the bladder were immunostained for EGFR and survivin. Bladder cancer tissue resected at surgery was also immunostained for EGFR and survivin expression. Tissue expression of EGFR and survivin in TCC of the bladder was compared to their expression in urine cytology and relationship to tumour grade and stage.

RESULTS

178 patients were studied (43 newly diagnosed bladder cancer, 58 with recurrent TCC and 77 in disease remission). Twenty five patients with normal urothelium served as controls. The mean sensitivity of urine cytology, tissue survivin immunohistochemistry (IHC) and tissue EGFR IHC was 30.5%, 62% and 59% respectively. The corresponding mean specificity was 95%, 79% and 38% respectively. For grades 1, 2 and 3 bladder tumors, tissue expression positivity for EGFR was 47.8%, 92.9%, 100% and for tissue survivin it was 27.8%, 18.2% and 33.3% respectively. For grades 1, 2 and 3 bladder tumors, urine expression positivity for EGFR was 35.7%, 40% and 67.7% and for urine survivin it was 8.3%, 42.9% and 33.3% respectively.

CONCLUSION

Positive EGFR immunostaining of urine cytology specimen or tumour tissue increases with histological grade of TCC of the bladder. Survivin expression is less consistent in both urine cytology specimen and tissue samples. EGFR immunostaining may provide a useful tool in the grading of bladder TCC and aid in the selection of patients that may benefit from administration of EGFR inhibitors.

Associations of adipokines & insulin resistance with sex steroids in patients with breast cancer

BACKGROUND & OBJECTIVES

Several studies have suggested an important, but conflicting and controversial role for adipose tissue mass in breast cancer risk. Factors such as insulin-like growth factors, sex steroids, adipokines and obesity-related inflammatory markers have been postulated as potential effectors of the mechanisms by which obesity and associated metabolic disorders influence breast cancer risk. In this study we evaluated the associations between obesity indices, insulin resistance, circulating adipokines, sex steroids and breast cancer.

METHODS

Fasting adiponectin, leptin, insulin resistance (homeostasis model assessment, HOMA-IR), testosterone, estradiol, sex hormone binding globulin (SHBG), LH and FSH were determined in 144 newly-diagnosed histologically confirmed breast cancer patients and 77 controls. Univariate and multivariate regression analyses were used to find the associations of these variables with each other, indices of obesity and with breast cancer.

RESULTS

BMI, waist circumference, HOMA-IR and leptin were significantly (P<0.001) higher in patients than in controls. Adiponectin level was also significantly (P<0.05) higher in patients compared to controls. Adiponectin and leptin showed significant correlations with insulin and HOMA-IR but only adiponectin was significantly correlated with estradiol and SHBG. Logistic regression analyses showed that factors associated with breast cancer were BMI [OR (95% CI) =2.8 (1.4-5.5), P=0.004]; high levels of adiponectin [5.1 (2.2-11.5), P<0.001); hyperinsulinaemia [1.1 (1.0-1.1), P=0.01], leptin [3.1 (1.7-5.7), P<0.0001], estradiol [2.5 (1.3-4.7), P=0.005] and testosterone [1.3 (1.03-1.7), P=0.03].

INTERPRETATION & CONCLUSIONS

Our findings confirm that adipokines, insulin resistance and sex steroids are associated with breast cancer. The paradoxical association of increased adiponectin with breast cancer is a novel finding that deserves further investigation.

Urinary survivin mRNA expression and urinary nuclear matrix protein 22 BladderChek® and urine cytology in the detection of transitional cell carcinoma of the bladder

OBJECTIVE

To compare the diagnostic performance of urine cytology (UC), survivin mRNA expression, and the NMP22 BladderChek® (NMP22BC) test for the detection, grading and staging of transitional cell carcinoma (TCC) of the bladder.

MATERIALS AND METHODS

Voided urine samples collected from 25 healthy controls and 80 patients diagnosed with TCC of the bladder were subjected to UC, the NMP22BC test and reverse-transcription real-time PCR for survivin mRNA expression.

RESULTS

Survivin mRNA expression showed the highest sensitivity (87.5%) followed by the NMP22BC test (61.3%) while UC exhibited the lowest sensitivity (40%). All three urine markers had a similar specificity of 96% (95% CI 80.5-99.3%). Survivin mRNA expression was the only urine marker that showed a significant difference in relation to tumour histological grade (χ(2) 8.5, p = 0.015). None of the three urine markers was significantly related to tumour pathological stages.

CONCLUSION

The diagnostic sensitivity of urinary survivin mRNA expression was superior to that of UC and the NMP22BC test and correlates with tumour pathological grade but not stage.

Distribution of human papillomavirus among women with abnormal cervical cytology in Kuwait

This study investigates the distribution of human papillomavirus (HPV) in women with abnormal cervical cytology in Kuwait. Two hundred and ninety-eight (298) abnormal ThinPreps were taken from women seeking routine gynecological care and screened for HPV DNA by real-time PCR. HPV genotyping was determined by PCR-based sequencing. HPV DNA was detected in 152 women (51%), and 29 different HPV genotypes were detected, comprising 16 high-risk (HR) (16, 18, 31, 33, 35, 39, 45, 51, 53, 56, 58, 59, 66, 68, 73, 97), nine low-risk (LR) (6, 11, 54, 61, 74, 81, 90, 102, 106), and four intermediate-risk (IR) (62, 67, 84, 87). HPV16 had the highest prevalence (24.3%), followed by HPV11 (13.8%), HPV66 (11.2%), HPV33 (9.9%), HPV53 (9.2%), HPV81 (9.2%), HPV56 (7.9%) and HPV18 (6.6%). HPV prevalence was 86, 67, and 89% in women with invasive cervical carcinoma (ICC), high-grade squamous intraepithelial lesion (HSIL) and low-grade squamous intraepithelial lesion (LSIL), respectively. As for age distribution, 69% of all HPVs were found in women aged 20-29 years, and the HPV incidence rate deceased with increasing age. The proportion of single infections decreased as the severity of the cytological diagnosis increased, while the proportion of multiple infections increased. This study is the first of its type in Kuwait and one of few in the Middle East. The findings are consistent with the hypothesis that HPV infection is the primary cause of cervical neoplasia. They support HPV vaccine research to prevent cervical cancer and efforts to develop HPV DNA diagnostic tests.

Associations of single nucleotide polymorphisms in the adiponectin gene with adiponectin levels and cardio-metabolic risk factors in patients with cancer

Objectives: The aims of this study are to (1) study the influence of polymorphisms in adiponectin gene on adiponectin levels and potential associations with breast, prostate and colon cancer; (2) investigate the associations of adiponectin levels with other adipokines and breast, prostate and colon cancers.

Subjects: We measured fasting adiponectin, leptin, insulin, Sex steroids in 132 (66 females, 66 males) cancer patients and 68 age and sex matched apparently healthy subjects. Body Mass Index (BMI) and waist circumference were used as indices of obesity. Insulin Resistance was assessed using Homeostasis Model Assessment (HOMA). Three single nucleotide polymorphisms (SNP rs182052 (G-10066-A), SNP rs1501299 (276G > T), SNP rs224176 (45T > G) in adiponectin gene were studied using Real Time Polymerase Chain Reaction.

Results: GG genotype of SNP rs1501299 was significantly associated with higher levels of adiponectin (OR=1.2, 95%CI(1.03–1.3), p = 0.02); breast (OR=8.6, 95%CI(1.03–71), p = 0.04), colon cancers (OR= 12, 95%CI(1.2–115), p = 0.03). GT genotype was also associated significantly with colon cancer (OR=2.6, 95%CI (1.1–6), p = 0.03). However SNP rs224176 was associated with only breast cancer.

Conclusion: Our results demonstrate that adiponectin gene SNP rs1501299 and SNP rs224176 may be the predisposing factors in some cancers but our results differ from what has been reported in other populations suggesting a complex relationship between genetic variations and phenotypic adiponectin levels.

Hepatitis B e Antigen Negative Chronic Hepatitis in Indian Patients : A Reality

BACKGROUND

Hepatitis B e antigen negative chronic hepatitis (e(-) CHB) with detectable levels of hepatitis B virus DNA (HBV DNA) in serum has been reported in cases from Asia. This study was undertaken to find out prevalence e(-)CHB and to correlate its presence with the clinical status and severity of the illness in cases of chronic liver disease in India.

METHODS

All patients of infective hepatitis, who were hepatitis B surface antigen (HBsAg) positive by enzyme-linked immunosorbent assay (ELISA), were evaluated with liver function tests and HBeAg and antiHBe antibody studies. Polymerase chain reaction (PCR) test was carried out to detect HBV DNA qualitatively.

RESULT

Out of 2064 samples tested by ELISA, 429 (20.78 %) were HBsAg positive. HBV DNA (qualitative) was performed on all 429 patients and 74 (17.2%) were HBV DNA positive. Of these only 42 (56.75 %) tested positive for HBeAg. Overall, 8.3 % of HBeAg negative patients (32/384) were viraemic with evidence of chronic liver disease/clinical cirrhosis and alteration of transaminase levels, while three cases (0.84 %) HBeAg positive cases did not show presence of HBV DNA.

CONCLUSION

This study shows e(-)CHB prevalence rate of 8.3% in patients with HBV infection in India. Since HBeAg negative patients had detectable levels of HBV DNA as seen in HBeAg positive patients, benefit of antiviral therapy should be given to them. Population studies on e(-) CHB cases are needed to determine its true prevalence, natural course and response to therapy.

WHONET Software for the Surveillance of Antimicrobial Susceptibility

Continuous surveillance of local antimicrobial susceptibility patterns is a must for combating emerging antimicrobial resistance. WHONET is an effective computerized microbiology laboratory data management and analysis program that can provide guidance for empiric therapy of infections, alert clinicians of trends of antimicrobial resistance, guide drug-policy decisions and preventive measures. The program facilitates sharing of data amongst different hospitals by putting each laboratory data into a common code and file format, which can be merged for national or global collaboration of antimicrobial resistance surveillance. The system can be implemented in hospital laboratories of Armed Forces at no additional cost. Cumulative analysis of surveillance data obtained from various hospitals of Armed Forces at higher centers may help in formulating health policies and control measures at various levels.

Her-2 neu (Cerb-B2) expression in fine needle aspiration samples of breast carcinoma: A pilot study comparing FISH, CISH and immunocytochemistry

Background:

Breast cancers with Her-2 neu gene amplification are recognized as important markers for aggressive disease and targets which respond to therapy with trastuzumab. Her-2 neu testing on histological sections is routinely performed to select patients who may benefit from anti- Her-2 neu therapy. Few reports are available which document Her-2 neu status on fine needle aspirates (FNA).

Aim:

This pilot study is to document expression of Her-2 neu (Cerb-B2) on cytospin smears from FNA of patients with breast carcinoma.

Materials and Methods:

Twenty samples of FNA already collected for diagnostic purposes from patients with primary breast carcinoma were studied for demonstration of Her-2 neu expression by immunohistochemistry (IHC), Fluorescent in-situ hybridization (FISH) and chromogenic in-situ hybridization (CISH) on cytospin smears from FNA. Their expression was compared with tissue sections where possible.

Results:

Good correlation was observed between Her-2 neu protein expression and gene amplification in cytospin smears. Three of five (60%) breast carcinomas cases with 2+ and 3+ staining on IHC showed gene amplification by FISH and CISH. Three of 7 (43%) and 5 of 7 (71%) cases negative/1+ staining on IHC did not show gene amplification by FISH and CISH respectively. Tissue sections from 10 cases with 2+ and 3+ staining for Her2neu by IHC showed gene amplification in 8 cases.

Conclusion:

Demonstration of Her-2 neu by IHC, FISH or CISH in FNA is possible and may play a role in the management of patients with advanced breast cancer or those cases where surgical resection is not advisable.

Comparison of the sensitivity and specificity of urine cytology, urinary nuclear matrix protein-22 and multitarget fluorescence in situ hybridization assay in the detection of bladder cancer

OBJECTIVE

This study aimed to compare the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of urine cytology, BladderChek® nuclear matrix protein-22 (NMP22) and UroVysion™ fluorescence in situ hybridization (FISH) tests in patients with newly diagnosed bladder cancer, those with recurrent bladder cancer, and those with bladder cancer but in remission during surveillance.

MATERIAL AND METHODS

Voided urine samples obtained from 178 patients with suspected or known bladder cancer about to undergo diagnostic or surveillance cystoscopy and 25 control subjects without the disease were divided into four and used for urine culture and cytology, NMP22 BladderChek and UroVysion FISH tests. The sensitivity, specificity, PPV and NPV for each test were calculated. Comparison was made between the ability of each test to detect bladder cancer in the three category of patients listed.

RESULTS

Of the 178 patients with bladder cancer, 43 were newly diagnosed, 58 had recurrent disease and 77 were in remission. The sensitivity of each test in newly diagnosed patients was: urine cytology 28%, NMP22 88% and FISH 80%; and in patients with recurrent disease: urine cytology 33%, NMP22 57% and FISH 85%. The mean specificity for urine cytology, NMP22 and FISH was 95%, 67% and 48%, respectively.

CONCLUSION

Of the tests used in the study for detection of bladder cancer, NMP22 appeared to be most cost-effective and rapid, with relatively high sensitivity and specificity in all categories of patients. The NMP22 test may be considered a new gold standard for the assessment of patients with known or suspected bladder cancer.

Fine needle aspiration cytology of the thyroid in children and adolescents: experience with 792 aspirates

OBJECTIVE

To determine the distribution of thyroid lesions in pediatric and adolescent patients in Kuwait.

STUDY DESIGN

During a 16-year period (January 1993-December 2008) the cytology reports of 792 thyroid aspirates (724 females and 68 males) performed on children and adolescents (ranging from 4 to 21 years) at Mubarak Al-Kabeer Hospital were reviewed. Of these 62, 150, 201 and 379 aspirates belonged to the age group 4-- <12, 12-- <16, 16-- <19 and 19-21 years, respectively. There were 745 satisfactory aspirates (678 [91%] females and 67 [9%] males). The unsatisfactory rate was 5.9%, with 51.1% of the unsatisfactory aspirates in the 19-21 age group.

RESULTS

Benign cytology was reported in 578 cases (77.6%), with 522 (70.1%) aspirates from females and 56 (7.5%) from males. Chronic lymphocytic thyroiditis was observed in 121 cases (16.2%), and 7 of these were males. Papillary carcinoma was detected in 20 (2.7%), and 4 of these were males. Suspicious cytology was reported only in females and comprised 7 cases (0.9%) with a suspicion of papillary carcinoma and 19 cases (2.6%) with a follicular lesion.

CONCLUSION

Fine needle aspiration cytology of children's and adolescents' thyroid nodules is feasible and reliable. The majority of the nodules in this age group are benign, and fine needle aspiration cytology helps prevent unnecessary surgery.

Survey of medical training in cytopathology carried out by the journal Cytopathology

This report of the Editorial Advisory Board of Cytopathology gives the results of a survey of medical practitioners in cytopathology, which aimed to find out their views on the current situation in undergraduate and postgraduate training in their institutions and countries. The results show that training in cytopathology and histopathology are largely carried out at postgraduate level and tend to be organized nationally rather than locally. Histopathology was regarded as essential for training in cytopathology by 89.5% of respondents and was mandatory according to 83.1%. Mandatory cytopathology sections of histopathology were reported by 67.3% and specific examinations in cytopathology by 55.4%. The main deficiencies in training were due to its variability; there were insufficient numbers of pathologists interested in cytology and a consequent lack of training to a high level of competence. Pathologists without specific training in cytopathology signed out cytology reports according to 54.7% of responses, more often in centres where training was 3-6 months or less duration. Although 92.2% of respondents thought that specialist cytology should not be reported by pathologists without experience in general cytopathology, that practice was reported by 30.9%, more often in centres with small workloads. The survey report recommends that 6-12 months should be dedicated to cytopathology during histopathology training, with optional additional training for those wanting to carry out independent practice in cytopathology. Formal accreditation should be mandatory for independent practice in cytopathology. When necessary, temporary placements to centres of good practice should be available for trainees intending to practise independently in cytopathology. There should be adequate numbers of pathologists trained in cytopathology to a high level of competence; some of their time could be released by training cytotechnologists and trainee pathologists to prescreen cytology slides and assess adequacy of fine-needle aspiration samples when immediate diagnosis was not required. The survey demonstrated a clear need for European and international guidelines for training in cytopathology.

Expression of estrogen receptor alpha and estrogen receptor beta in fine needle aspirates of breast carcinoma

OBJECTIVE

To evaluate the expression of estrogen receptor beta (ERbeta) in fine needle aspirates (FNAs) and correlate the findings with its expression in tissue sections.

STUDY DESIGN

In 38 cases of breast carcinoma, expression of estrogen receptor alpha (ERalpha) and ERbeta in aspirates and tissue sections was correlated with the cytologic and histologic grade of the tumor.

RESULTS

ERalpha and ERbeta were expressed as nuclear staining in 80% and 90% of the cases in tissue sections and 47% and 45% of the cases in aspirates, respectively. Tissue expression of ERalpha (grade 1, 81%; grade 2, 100%) and ERbeta (grade 1, 94%; grade 2, 100%) was greater than in grade 3 tumors (ERalpha, 50%; ERbeta, 70%). In FNAs they were equally distributed in the different cytologic grades. In aspirates 30% of ERalpha negative tumors were positive for ERbeta, while in tissues 75% of ERalpha-negative tumors were positive for ERbeta (p = 0.007).

CONCLUSION

Demonstration of ERbeta on FNA smears is feasible. It helps identify the specific subcohort of ERbeta-positive tumors in ERalpha-negative breast cancers; that may have therapeutic importance.

Gynecologic infections seen in cervical smears in Kuwait

OBJECTIVE

To study the different gynecologic infections seen in cervical smears in Kuwait.

STUDY DESIGN

Over a 6-year period (2002-2007), a total of 42,294 cervical smears were studied in Mubarak Al-Kabeer Hospital, Kuwait. Conventional and ThinPrep (Cytyc Corp. Boxborough, Massachusetts) smears were first screened by cytotechnicians and finally reported by cytopathologists, Smears showing inflammation were analyzed with reference to Kuwaiti women.

RESULTS

Of the 41,748 (98.7%) patients with satisfactory smears, inflammatory changes were observed in 17, 593 (42.1%). Specific infection was identified in 2,679 (15.2%) cases, of which 60.8% were Kuwaitis. The infections seen were Candida sp (73.8%), Trichomonsa vaginalis (11.9%), human papillomavirus (HPV99) (8.2%), Actinomyces-like organisms (3.4%), Chlamydia trachomatis (2.2%) and herpes simplex virus (0.5%). No significant difference was found in the proportion of infectious agents among Kuwaiti and non-Kuwaiti women except marginally higher T vaginalis (10.9% vs 13.4%, p = 0.05) among non-Kuwaitis. Candida sp was the most detectable infectious agent in both Kuwaiti (74.6%) and non-Kuwaiti women (72.4%). Chi2 for trend revealed an increasing proportion of smears from Kuwaiti women found with specific infections (p = 0.049) as compared to those of non-Kuwaitis over the years.

CONCLUSION

The prevalence of infections identified on cervical smears was found to be almost similar in Kuwaiti and non-Kuwaiti women except for T vaginalis, which was higher among non-Kuwaitis as compared to Kuwaitis (10.9% vs. 13.4%, p = 0.051). The Candida sp was the most detectable infectious agent, 74.6% in Kuwaiti and 72.4% in non-Kuwaiti women, followed by T vaginalis, the second and HPV being the third.

Human immunodeficiency virus type 1 gp 41 mutations in proviral DNA among antiretroviral treatment-naive individuals from India

The HIV-1 gp41 has been identified as an important target for the immune response, for the development of antiviral and vaccine strategies, and for epidemiologic studies. This study describes the HIV-1 env gp41 region mutations, associated with enfuvirtide (ENF) resistance, in proviral DNA from PBMCs in antiretroviral treatment-naive individuals from Pune, India. Twenty-one antiretroviral drug-naive chronically HIV-1-infected individuals were enrolled. The study sequences belonged to subtype C (n = 17), subtype A1 (n = 2), and CRF_AE (n = 2). In subtype B-infected individuals, the various HR1 region substitutions in env gp41 that have been associated with ENF resistance include A30V, L33S/T/V, L34M, G36D/E/S/V, I37T/K/V, V38A/M/E/G, Q39R, Q40H, N42T/D, N43D/K/S, L44M, L45M, R46M, L54M, and Q56K/R as well as N126K and S138A in the HR2 region. The study sequences did not reveal any ENF resistance-associated mutations at env gp41 amino acid positions: 36 to 45. The presence of L54M and Q56K in combination is associated with 5-fold reduced sensitivity to inhibition by ENF. The mutation L54M was seen in seven subtype C and two CRF_AE study sequences. Q56K was observed in a subtype A1 sequence. All the study sequences harbored N42S, a natural polymorphism associated with increased susceptibility to ENF. Of the mutations V38A and N140I, known to provide immunologic gain, the latter was observed in four subtype C sequences. This is the first study from India highlighting the presence of certain mutations in Indian subtype C env gp41, which may play a role in the evolution of subtype-specific variations in the resistance to ENF and associated immune response.

Divergent strains of human immunodeficiency virus type 1 circulating in India, subtyped by heteroduplex mobility assay

Genomic variations in HIV-1 represent a major problem in understanding disease progression, studying drug resistance and developing effective vaccines. Heteroduplex Mobility Assay (HMA) was used for analyzing HIV-1 subtypes resulting from genetic similarity or divergence of C2 -V3 -V5 region of envelope gene between HIV-1 strains obtained from clinical samples in a tertiary care center at Pune. DNA from the PBMCs of infected individuals was amplified by nested PCR. Heteroduplexes were then formed by denaturing DNA from the unknowns with DNA from the reference strains. The results were analyzed by polyacrylamide gel electrophoresis. Out of 177 samples analyzed, 170 were of subtype C (96%). Four samples were found to be of subtype B (2.2%); in three samples, no definitive assignment of subtype was possible by HMA and these perhaps could be circulating recombinant forms (CRFs) of HIV-1. These findings may have significant implications toward development of a candidate vaccine for India.

Comparison of cefoxitin disc diffusion test, oxacillin screen agar, and PCR for mecA gene for detection of MRSA

Cefoxitin is a potent inducer of the mecA regulatory system. It is being recommended for detection of methicillin resistance in Staphylococcus aureus (MRSA) when using disk diffusion testing. The aim of our study was to evaluate the efficacy of cefoxitin disc diffusion test to characterize MRSA and compare it with oxacillin agar screening and detection of mecA gene by PCR.

MATERIALS AND METHODS

Fifty strains of S. aureus isolated from clinical samples were used in the study. Routine antibiotic susceptibility testing was performed including oxacillin disk. Oxacillin screen agar plates with 4% NaCl and 6 microg/ml of oxacillin were inoculated and interpreted as per standard guidelines. Cefoxitin disc diffusion test was performed using 30 microg disc and zone sizes were measured. PCR for amplification of the mecA gene was performed.

RESULTS

Out of the 50 isolates, 28 were found to be methicillin resistant by oxacillin disc diffusion test, 30 were resistant by oxacillin screen agar method, and 32 were resistant with cefoxitin disc diffusion. For these 32 isolates mecA gene was positive.

CONCLUSION

Results of cefoxitin disc diffusion test is in concordance with the PCR for mecA gene. Thus, the test can be an alternative to PCR for detection of MRSA in resource constraint settings.