Human immunodeficiency virus type-2 (HIV-2) belongs to the family retroviridae which is phylogenetically clusters with SIV _SM from sooty mangabeys. This virus is morphologically similar to human immunodeficiency virus type-1 (HIV-1) but has got only a 40% homology at the nucleotide level. There is a distinct geographical distribution of HIV-2 unlike HIV-1. There are currently eight subtypes/groups identified with subtype/group A responsible for the majority of infections. HIV-2 shows a considerable difference in the course of the disease. Clinical, haematological and immunological evaluation of individuals infected with HIV-2 has shown the virus to be less pathogenic than HIV-1 although the exact mechanism underlying this difference is not well defined. Similar to HIV-1, the HIV-2 isolates also showed distinct replicative and cytopathic characteristics. The transmission rate for HIV-2 compared to HIV-1 is very low both by heterosexual route and mother to child transmission. The clinical signs and symptoms of immunodeficiency associated with HIV-2 are similar to the ones seen among the HIV-1-infected individuals and they can also progress to AIDS. It is naturally resistant to NNRTI and hence the diagnosis become important as it affects the treatment strategy. Similar to HIV-1, HIV-2 strains of infected individuals also show mutations that can cause drug resistance. The current evidence suggests that there is no protective effective for HIV-2 against HIV-1.

Increasing prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) worldwide is a growing public health concern. MRSA typing is an essential component of an effective surveillance system to describe epidemiological trends and infection control strategies. Current challenges for MRSA typing are focused on selecting the most appropriate technique in terms of efficiency, reliability, ease of performance and cost involved. This review summarises the available information on application, potential and problems of various typing techniques in discriminating the strains and understanding the epidemiology of MRSA strains. The phenotypic methods in general are easier to perform, easier to interpret, cost effective and are widely available, however less discriminatory. The genotypic methods are expensive and technically demanding, however more discriminatory. Newer technologies involving sequencing of various genes are coming up as broadly applicable and high throughput typing systems. Still there is no consensus regarding the single best method for typing of MRSA strains. Phage typing is recommended as first line approach in epidemiological investigation of MRSA strains. PFGE remains the gold standard for characterisation of outbreak strains. DNA sequencing methods including MLST, spa typing, SCCmec typing and toxin gene profile typing are more practical methods for detecting evolutionary changes and transmission events. The choice of typing technique further depends on the purpose of the study, the facilities available and the utility of data generated to answer a desirable research question. A need for harmonisation of typing techniques by following standard protocols is emphasised to establish surveillance networks and facilitate global MRSA control.

Purpose: Noroviruses (NoV) are increasingly recognized as an important cause for acute gastroenteritis, worldwide. Reverse transcription polymerase chain reaction (RT-PCR) and sequencing are the methods of choice for the detection of NoVs, but there is currently no consensus about the primers to be used in these assays. Materials and Methods: In this study, five published primer sets were evaluated for the detection of genogroup II (GII) NoVs in India. The primers target different regions of the NoV genome. Three primer sets detect an NoV in a single round RT-PCR platform, while the remaining two primer sets are based on a nested RT-PCR platform. Result: A panel of 100 samples from previous studies on norovirus diarrhoea in children were tested by all five primer sets. Of them, 74 samples were identified as positive for NoV, by at least one primer set. Subsets of positive amplicons were sequenced to check for specificity. Conclusion: The most sensitive primer set was Girish 2002, which detected GII NoV by nested RT-PCR, and was modified from the previously published primers. This study demonstrates that higher detection can be obtained by either using multiple primer sets or using a sensitive nested RT-PCR assay. It also demonstrates the differences in primer sensitivity for detection of Genogroup II (GII) NoVs in India.

Purpose: The present study was performed to assess the current susceptibility pattern of blood isolates of Salmonella spp from a super specialty hospital in North India against nalidixic acid, ciprofloxacin and azithromycin and compare the in vitro and in vivo response against azithromycin. Materials and Methods: We evaluated the minimum inhibitory concentration's (MIC's) of 107 blood isolates of Salmonella spp against nalidixic acid, azithromycin and ciprofloxacin and correlated in vitro and in vivo response of azithromycin from the treatment and discharge summaries from the Hospital Information System (HIS) software. Results: Among the 107 isolates evaluated, 94 (87.8%) were nalidixic acid-resistant (NAR) Salmonella and 36 were resistant to azithromycin by MIC testing. The MIC ₉₀ value for azithromycin was 24 μg/mL. Among the 57 treatment histories evaluated using the HIS software, 19 (33%) patients had documented clinical non-response to azithromycin which required change of therapy. Conclusions: The present study observed a higher MIC ₉₀ values for azithromycin compared to Salmonella isolates from Western studies. There was also a documented clinical non-response against azithromycin. The in vitro and in vivo findings in this study suggest a guarded use of azithromycin for cases of enteric fever in India. The study also augments the reversal of resistance pattern in favour of chloramphenicol, ampicillin and trimethoprim - sulfamethoxazole.

Purpose: In vitro pharmacodynamic properties of colistin methanesulfonate and amikacin were investigated by studying time-kill kinetics and post-antibiotic effect (PAE) against strains of Pseudomonas aeruginosa isolated from patients with cystic fibrosis. Method: Synergy was investigated at 0.5×, 1× and 5× MIC of antibiotics using time-kill curve method. PAEs were determined by the standard viable counting method where bacteria in the logarithmic phase of growth were exposed for 1 h to the antibiotics at 1× or 20× MIC, alone and in combinations. Synergy and additive effects were detected at 1×MIC, at 24 h. Results: Some of the strains produced an earlier synergistic effect at 12 h. No antagonism was observed. Colistin methanesulfonate and amikacin produced PAEs 1.16 ± 0.10 to 2.25 ± 0.16 h and 0.96 ± 0.15 to 2.69±0.32 h, respectively. When the antibiotics were used in combination the PAEs were prolonged to a value of 3.88±0.25 h. Consequently, the Conclusions: Findings of this study may play useful role in selecting the appropriate combinations when a single agent is inadequate, and may have important information for optimizing the dose intervals.

Purpose: Vibrio cholerae, the cause of cholera, is one of the leading causes of morbidity and mortality in many developing countries. Most laboratories initially rely on biochemical tests for a presumptive identification of these strains, followed by a polymerase chain reaction (PCR)-based method to confirm their identification. The aim of this study is to establish a rapid and reliable identification scheme for V. cholerae using a minimal, but highly specific number of biochemical tests and a PCR assay. Materials and Methods: We developed a species-specific PCR to identify V. cholerae, using a housekeeping gene recA, and used that to evaluate the sensitivity and specificity of 12 biochemical tests commonly used for screening and / or presumptive identification of V. cholerae in the clinical and environmental samples. Results: Here we introduced a combination of three biochemical tests, namely, sucrose fermentation, oxidase test, and growth in trypton broth containing 0% NaCl, as also the PCR of the recA gene, for rapid identification of V. cholerae isolates, with 100% sensitivity and specificity. The established method accurately identified a collection of 47 V. cholerae strains isolated from the clinical cases (n = 26) and surface waters (n = 21), while none of the 32 control strains belonging to different species were positive in this assay. Conclusion: The triple-test procedure introduced here is a simple and useful assay which can be adopted in cholera surveillance programs for efficient monitoring of V. cholerae in surface water and fecal samples.

Purpose: Vancomycin-resistant enterococci (VRE) pose an emerging problem in hospitals worldwide. The present study was undertaken to determine the occurrence, species prevalence, antibacterial resistance, and phenotypic and genetic characteristics of VRE isolated in Riyadh hospitals, KSA. Materials and Methods: Two hundred and six isolates of enterococcal species were obtained from clinical samples. The antibiotic susceptibility of isolates and minimum inhibitory concentration (MIC) tests for vancomycin and teicoplanin were determined. Molecular typing of VRE isolates was carried out by using pulsed field gel electrophoresis (PFGE) and the resistance genotype was determined by polymerase chain reaction (PCR). Results: VRE accounted for 3.9% of the isolates and were detected mostly in urine, wound and blood specimens isolated from ICU, internal medicine and surgical wards. All strains were identified to species level and were found to consist of E. faecalis (69.2%), E. faecium (11.3%), E. avium (2.1%), E. hirae (0.8%), E. casseliflavus (1.3%) and E. gallinarum (1.3%) species. According to the susceptibility data obtained, 8 (3.9%) out of 206 isolates were found to be VRE (MICs > 32 μg/ml). The vanA, vanB and vanC gene fragments of E. faecalis, E. faecium and E. gallinarum were amplified from isolates and were detected. PFGE patterns of the VRE isolates revealed homogenous patterns with dominant clone suggesting that the strains intrinsic resistance is independent. Conclusions: This study shows an emergence of VRE along with increased rate of multidrug-resistant enterococci in the area of the study. Regular surveillance of antimicrobial susceptibilities should be done regularly and the risk factors should be determined.

Purpose: Coryneform or the non-diphtherial Corynebacterium species largely remains a neglected group with the traditional consideration of these organisms as contaminants. This concept, however, is slowly changing in the light of recent observations. This study has been done to find out the species distribution and antibiogram of various members of the clinically relevant Coryneform group, isolated from various clinical materials. Materials and Methods: One hundred and fourteen non-duplicate isolates of diphtheroids from various clinical isolates were selected for the study. The isolates were identified to the species level by using a battery of tests; and antimicrobial susceptibility was tested by using a combination of Clinical and Laboratory Standards Institute (CLSI) and the British Society for Antimicrobial Chemotherapy (BSAC) guidelines, in the absence of definitive CLSI guidelines. Results: Corynebacterium amycolatum was the predominant species (35.9%) in our series followed by the CDC Group G organisms (15.7%). Each of the remaining 19 species comprised of less than 10% of the isolates. More than half the total isolates were resistant to the penicillins, erythromycin, and clindamycin; while excellent activity (all the strains being susceptible) was shown by vancomycin, linezolid, and tigecycline. Chloramphenicol and tetracycline also had good activity in inhibiting more than 80% of the isolates. Multiply drug resistance was exhibited by all the species. Conclusion: This study was an attempt to establish the clinical significance of coryneform organisms. The high level of resistance shown by this group to some of the common antibacterial agents highlights the importance of processing these isolates in select conditions to guide the clinicians towards an appropriate therapy.

Purpose: Molecular methods which allow rapid detection of tuberculosis as well as drug resistance directly from clinical samples have become the most popular diagnostic methodology with the emergence of multidrug resistant tuberculosis. The aim of the present study was to evaluate the performance of a line probe assay, GenoType MTBDRplus for the rapid detection of Mycobacterium tuberculosis and mutations causing rifampicin and INH resistance directly in smear positive pulmonary specimens and also in M. tuberculosis isolates grown from various clinical specimens. Materials and Methods: The MTBDRplus assay was done directly on 37 smear positive pulmonary specimens and also on 69 M. tuberculosis isolates obtained by rapid automated culture using Bact/Alert 3D. The results were compared with phenotypic drug susceptibility testing (1% proportion method) using Bact/Alert 3D. Results: The sensitivity and specificity for detection of resistance to rifampicin was 100% and 97.3%, and to INH was 91.9% and 98.4%, respectively, in comparison with the phenotypic drug susceptibility testing. Conclusion : MTBDRplus assay had good sensitivity and specificity with turn around time of less than 48 hours. It may be a useful tool for rapid detection of multidrug resistant tuberculosis at a tertiary care centre.

Purpose: Tuberculosis (TB) is endemic in India and the burden of multi-drug-resistant tuberculosis (MDR-TB) is high. Early detection of MDR-TB is of primary importance in controlling the spread of TB. The microscopic observational drug susceptibility (MODS) assay has been described as a cost-effective and rapid method by which mycobacterial culture and the drug susceptibility test (DST) can be done at the same time. Materials and Methods: A total of 302 consecutive sputum samples that were received in an accredited mycobacteriology laboratory for conventional culture and DST were evaluated by the MODS assay. Results: In comparison with conventional culture on Lowenstein Jensen (LJ) media, the MODS assay showed a sensitivity of 94.12% and a specificity of 89.39% and its concordance with the DST by the proportion method on LJ media to isoniazid and rifampicin was 90.8% and 91.5%, respectively. The turnaround time for results by MODS was 9 days compared to 21 days by culture on LJ media and an additional 42 days for DST by the 1% proportion method. The cost of performing a single MODS assay was Rs. 250/-, compared to Rs. 950/- for culture and 1st line DST on LJ. Conclusion: MODS was found to be a sensitive and rapid alternative method for performing culture and DST to identify MDR-TB in resource poor settings.

Purpose: The fight against Healthcare-associated infections is a public health priority and a major challenge for the safety and quality of care. The objective was to assess hygiene in general practitioners' (GPs') office and identify barriers to and drivers for better practice. Materials and Methods: We performed a cross-sectional study in which a questionnaire was sent to a randomly selected, representative sample of 800 GPs. We used a self-administered questionnaire. The first part assessed current practice and the second part focused on barriers and motivating factors for better practice. We performed a descriptive statistical analysis of the responses to closed questions and a qualitative analysis of the responses to open-ended questions. Results: Only a third of the GPs were aware of the current guidelines. Disposable equipment was used by 31% of the GPs. For the remainder, only 38% complied with the recommended procedures for sterilisation or disinfection. Seventy-two percent of the GPs washed their hands between consultations in the office. A significant minority of physicians disregarded the guidelines by never wearing gloves to perform sutures (11%), treat wounds (10%), fit intrauterine devices (18%) or perform injections (18%). The main barriers to good practice were the high cost of modifications and lack of time/space. Two third of the GPs did not intend to change their practices. The drivers for change were pressure from patients (4.8 on a scale of 1 to 7), inspection by the health authorities (4.8) and the fear of legal action (4.4). Conclusions: Our results show that there are significant differences between current practice and laid-down professional guidelines. Policies for improvement of hygiene must take into account barriers and motivating factors.

Background: Bacterial species are capable of living as biofilm and/or planktonic forms. There is increasing evidence for the role of bacterial biofilm in various wound and urinary tract infections (UTIs). The aim of the present study was to evaluate the ability of the bacteria, isolated from urinary tract infections (UTIs) and wound infections, to form biofilm and correlate the role of biofilm with their antimicrobial resistance. Materials and Methods: All the isolated bacteria were screened for their ability to form biofilm using the microtitre plate method. Results: Wound isolates of Staphylococcus aureus and Enterobacter sp. had more biofilm forming capacity than the UTI isolates. Proteus mirabilis isolates were among the strongest biofilm forming bacteria and were chosen for antimicrobial study. In sub-MIC concentrations of antimicrobial agents used, ciprofloxacin was found to be the most effective in decreasing biofilm formation. On the other hand, ceftriaxone and ciprofloxacin were effective in partial removal of preformed biofilm biomass. Conclusion: Ciprofloxacin was more effective in killing bacterial cells especially at high antimicrobial concentrations that could be reached in urine levels and can be used in impregenating catheters.

Colorimetric methods are cheap, reproducible, and rapid methods of detecting drug resistance in Mycobacterium tuberculosis. The MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) method is one such technique that has been established in our laboratory to detect rifampicin resistance. The present study compared the results of the MTT method with those of the proportion method and real-time polymerase chain reaction (RTPCR) in order to establish sensitivity and specificity of MTT. The mutations for rifampicin resistance occur in rpoB gene, and the commonest reported are in codons 526 and 531. Therefore, RTPCR was targeted at these two codons. The concordance of MTT with the proportion method and RTPCR was 94 and 72.77%, respectively, and that of RTPCR with the proportion method was 77.77%. While the study confirmed that the MTT method is a good method for detecting rifampicin resistance, it also brought out the fact that RTPCR when targeted for limited mutations is not a good tool. Either the genotypic method used should target the total 81-bp rpoB genome or methods such as DNA sequencing should be used. For resource-constraint laboratories, the MTT method can be considered as a better choice.

Campylobacter spp. are an important cause of bacterial gastroenteritis frequently isolated from animal, poultry and environmental samples. In this study, we investigated the zoonotic potential of Campylobacter spp. by comparing prevalence rates and species in 394 children with diarrhoea and 652 animals in Vellore using PCR-based tools. Eighteen children (4.5%) had campylobacteriosis, a majority of whom had co-pathogens (15/18) and most were infected with Campylobacter jejuni (16/18). A few C. coli and mixed infections with both species were also seen. Among the animal samples, 16/25 chicken samples (64%) were positive and all were found to be C. jejuni.

A preliminary study was conducted to see the prevalence of Clostridium difficile in patients and their environment in a tertiary care hospital. Seventy-nine fecal specimens from hospitalized patients, 176 swab samples from beds and 48 from hands of hospital personnel were investigated. Sixty-three patients received antibiotics and 14 proton pump inhibitors. Abdominal pain was observed in 16 patients with fever in 15 of them. C. difficile culture was positive in 12.6% patients at initial sampling but none were toxin-positive. Eight patients developed diarrhea and five were both culture and toxin-positive. Fifty-one percent of bed swab samples and 62.5% of hand swab samples were culture positive. Similarly 8.5% of bed swab samples and 4.2% of hand swab samples were positive for toxins A and B. The environmental cross-infection between patients and carriage by hospital personnel are plausible sources of C. difficile infection and spread in our hospital.

Carbapenem resistance among clinical isolates of Enterobacteriaceae, especially Escherichia coli and Klebsiella pneumoniae, is largely conferred by metallo-β-lactamase (MBL). Fifty-one non repetitive isolates of carbapenem-resistant (Meropenem and Imipenem) E. coli and K. pneumoniae were studied to determine the molecular mechanism for resistance. Presence of bla_NDM and bla_VIM was determined by polymerase chain reaction (PCR) and DNA sequencing. bla_NDM was detected from majority of carbapenem-resistant K. pneumoniae (75%) and E. coli (66.6%). Timely detection and appropriate and aggressive infection control measures are required to control the spread of these bacteria in healthcare settings.

The present study highlights six cases of pneumococcusuria during the time period of May 2008 to May 2010. All the patients had a co-existing predisposing factor with the isolation of Streptococcus pneumoniae in urine. Five of the six patients having signs and symptoms of urinary tract infections (UTI) were treated and cured of the same. It becomes essential to consider pneumococcal UTI in the presence of clinical signs and symptoms associated with urinary tract abnormalities like hydronephrosis and renal stones. S. pneumoniae may be regarded as an emerging pathogen in UTI. Precise microbiological diagnosis must correlate with the clinical signs and symptoms for the administration of appropriate antibiotic therapy.

Tuberculosis is considered as a 're emerging disease', because of its resurgence and increased incidence in the 21 ^st century particularly in immuno-compromised patients. About one fifth of diagnosed new cases of tuberculosis have an extrapulmonary lesion, of which about one-tenth involve the musculoskeletal system. Tuberculosis involving the soft tissue from adjacent bone or joint is well recognized but cutaneous tuberculous infection is rare, accounting for 0.1% of all cases seen in a dermatology service. We report a case of primary cutaneous tuberculosis of forearm following a vehicular accident in a young immunocompetent female.

Isolated splenic tuberculosis is an exceedingly rare clinical condition. Microbiological confirmation of diagnosis in such cases is quite difficult. We encountered the case of a 35-year-old female, who presented with persistent low-grade fever and weight loss. The CT scan of the abdomen revealed multiple hypodense splenic lesions. No primary focus of infection was detected in any other organs. Fine needle aspiration of splenic lesion revealed acid-fast bacilli on Ziehl-Neelsen stain. With anti-tuberculous therapy, the lesions regressed significantly in size. We stress that splenic tuberculosis should be considered as a diagnostic possibility even in immunocompetent individuals and choose combination antituberculous therapy as the first line treatment with consideration of splenectomy depending on response.

India is endemic for both Leptospira and hepatitis E virus (HEV). The clinical presentations of these diseases have overlapping features. We report a case of superinfection of HEV in a patient with resolving leptospirosis with underlying Hodgkin lymphoma. The diagnosis of HEV in our case was established by HEV-RNA PCR as our patient was immunosuppressed. The present study highlights the need for molecular diagnosis in the case of HEV infection with strong clinical suspicion and negative serological results.

A bladder infection of Aspergillus with no evidence of dissemination is rare. We present a case of Aspergillus infection with transitional cell carcinoma of the urinary bladder without any evidence of systemic involvement. A 65-year-old male diabetic whose main complaints were intermittent painful haematuria and nocturia had undergone nephroureterectomy a year and a half back for transitional cell carcinoma of right renal pelvis. Cystoscopy revealed bladder mucosa having fixed broad tumour with encrustation and bleeding on touch at the right vesico-ureteric junction. The histopathologic diagnosis was a high-grade transitional carcinoma with Aspergillus infection. Fungal culture of urine obtained after bladder wash yielded Aspergillus fumigatus.

Rhinosporidiosis is a chronic granulomatous infection caused by Rhinosporidium seeberi. Rhinosporidiosis has been reported from many countries but is endemic in certain parts of India and Sri Lanka. The common sites of involvement are the nose and nasopharynx followed by ocular tissue. Rhinosporidiosis is also known to involve many rare sites and may become disseminated to occur in a generalized form. Rhinosporidiosis of the parotid duct is rare and only five reported cases could be found in the literature. We report three cases of rhinosporidiosis of parotid duct presenting clinically as a parotid duct cyst. Rhinosporidiosis was diagnosed by histopathology. None of these patients had rhinosporidiosis at any other site