Bacterial infections and emerging resistance in renal transplant recipients.

Objective: Renal transplantation is frequently complicated by bacterial infections in the scenario of immunosuppression, altered metabolism and interventions resulting in prolonged morbidity. Subdued clinical presentation, antimicrobial resistance and toxicity question the outcome of transplantation. This retrospective study conducted at tertiary care apex transplant centre highlights colonization, clinical infection and antimicrobial resistance patterns in Renal Transplant Recipients (RTR). Materials and methods: Infection and antimicrobial resistance patterns in 130 RTR were studied. Clinico-demographic and transplant parameters were noted. Infection screening in the post transplant period along with antimicrobial susceptibility were used to analyze data in a post transplant time frame. Results and discussion: Culture positivity timeline was dominated by post surgical infections in the first week post transplant. Urinary infections followed by blood stream infections were noted. Infection profile included simultaneous polymicrobial, prolonged and widespread infections. Multi-resistant organisms producing beta lactamases and extended spectrum beta lactamases were isolated. Conclusion: Transplant recipients remain prone to bacterial infections with multi-resistant organisms which may persist due to immunosuppression, altered metabolism and toxicity, and contribute to nosocomial hazard. Infection control may be targeted at avoidance of donor derived infections, surgical complications, epidemiologic exposures, strengthening antimicrobial prophylaxis and anti-infection engineering. Antimicrobial stewardship, outbreak and epidemic preparedness should be ensured.

Phenotypic detection of Extended Spectrum Beta-Lactamases and Amp C Beta- Lactamases among nosocomial isolates in a tertiary care hospital.

Background & objectives: Extended-Spectrum Beta-Lactamases (ESBLs) is an important resistance mechanism in Enterobacteriaceae infections. Lack of standard guidelines from Clinical Laboratory Standards Institute (CLSI) for Amp C beta-lactamase detection poses a problem. This study was undertaken to detect ESBLs by phenotypic tests and Amp C beta-lactamase by inhibitor based method. Material and Methods: 200 consecutive non-repetitive isolates of E.coli, Klebsiella and Proteus from clinical samples were screened for ESBLs as per CLSI guidelines and confirmed by PCDT, DDST and E-tests (AB Biodisk, Biomerieux). Amp C beta lactamases were screened by cefoxitin resistance and confirmed by inhibitor (Cloxacillin) based method. Simultaneous occurrence of Amp C and ESBLs was detected by combined disk test (Neo-Sensitabs and Diatabs). Descriptive and Kappa statistics were used. Results: Out of 200 isolates studied, 131 were initially screened as ESBL producers and later 114 (57%) were confirmed by phenotypic methods. E-Test was found most sensitive phenotypic test as compared to PCDT and DDST. 13 strains resistant to cefoxitin (30μg) were found to be pure Amp C producers. Combined disk test detected 36 to be ESBL and Amp C co-producers. Surprisingly, six isolates found sensitive to cefoxitin disk were confirmed as Amp C producers by cloxacillin disk inhibition test. Conclusion: 57% ESBLs and 27.5% Amp C producers were isolated from nosocomial pathogens showing significant resistance to 3rd generation cephalosporins. Phenotypic confirmation by E-test, PCDT & DDST were useful for ESBL identification and for detection of Amp C, cloxacillin was found to be an effective inhibitor.

Evaluation of a commercial Dengue NS1 enzyme-linked immunosorbent assay for early diagnosis of dengue infection.

Purpose: Dengue is one of the most serious mosquito-borne viral infections affecting tropical and subtropical countries in the world. Since there is no immunoprophylactic or specific antiviral therapy available, timely and rapid diagnosis plays a vital role in patient management and implementation of control measures. This paper evaluates a commercially available NS1 antigen capture ELISA vis-a-vis SD bioline Dengue NS1 antigen test for early detection of dengue virus. Materials and Methods: To evaluate a commercial NS1 antigen detection kit vis-a-vis SD bioline Dengue NS1 antigen test, a total of 91 clinical samples were tested. Virological investigations with regard to dengue virus, viz. NS1 antigen capture ELISA (Panbio, Australia), SD bioline Dengue NS1 antigen test, RT-PCR and virus isolation were performed. Results: Out of 91 samples, 24 (26%) were positive by NS1 antigen capture ELISA, 15 (16%) by SD bioline Dengue NS1 antigen test and 11(12%) positive by RT-PCR analysis. The RT-PCR-positive samples were further subjected to virus isolation and resulted in three isolates. The results of the Panbio NS1 antigen capture ELISA, SD bioline Dengue NS1 antigen test, RT-PCR and virus isolation were correlated among themselves. Conclusions: The present study comprehensively established the utility of NS1 antigen ELISA in early diagnosis of dengue infection.

Deccan volcanism, the KT mass extinction and dinosaurs

Recent advances in Deccan volcanic studies indicate three volcanic phases with the phase-1 at 67.5 Ma followed by a 2 m.y. period of quiescence. Phase-2 marks the main Deccan volcanic eruptions in Chron 29r near the end of the Maastrichtian and accounts for ~80% of the entire 3500 m thick Deccan lava pile. At least four of the world’s longest lava fl ows spanning 1000 km across India and out into the Gulf of Bengal mark phase-2. The fi nal phase-3 was smaller, coincided with the early Danian Chron 29n and also witnessed several of the longest lava fl ows. The KT boundary and mass extinction was fi rst discovered based on planktic foraminifera from shallow marine intertrappean sediments exposed in Rajahmundry quarries between the longest lava fl ows of the main volcanic phase- 2 and smaller phase-3. At this locality early Danian (zone P1a) planktic foraminiferal assemblages directly overlie the top of phase-2 eruptions and indicate that the masse extinction coincided with the end of this volcanic phase. Planktic foraminiferal assemblages also mark the KT boundary in intertrappean sediments at Jhilmili, Chhindwara, where freshwater to estuarine conditions prevailed during the early Danian and indicate the presence of a marine seaway across India at KT time. Dinosaur bones, nesting sites with complete eggs and abundant eggshells are known from central India surrounding the hypothesized seaway through the Narmada-Tapti rift zone. A Maastrichtian age is generally assigned to these dinosaur remains. Age control may now be improved based on marine microfossils from sequences deposited in the seaway and correlating these strata to nearby terrestrial sequences with dinosaur remains.

The origin and early evolution of whales: macroevolution documented on the Indian Subcontinent.

The origin of whales (order Cetacea) from a four-footed land animal is one of the best understood examples of macroevolutionary change. This evolutionary transition has been substantially elucidated by fossil fi nds from the Indian subcontinent in the past decade and a half. Here, we review the fi rst steps of whale evolution, i.e. the transition from a land mammal to obligate marine predators, documented by the Eocene cetacean families of the Indian subcontinent: Pakicetidae, Ambulocetidae, Remingtonocetidae, Protocetidae, and Basilosauridae, as well as their artiodactyl sister group, the Raoellidae. We also discuss the infl uence that the excellent fossil record has on the study of the evolution of organ systems, in particular the locomotor and hearing systems.

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.

Early detection of HIV-1 in infants by PCR.

Infants of HIV-infected mothers are at great risk of becoming infected with HIV during childbirth. Many infants acquire HIV during labor and delivery. Others can acquire HIV through the mixing of fetal and maternal blood as the placenta separates. The duration of membrane rupture, acute chorioamnionitis and invasive delivery techniques that increase the baby's contact with the mother's blood have been associated with higher risks of MTCT during labor and delivery. HIV is present in breast milk and risk of its transmission during breastfeeding depends on several factors, including: infant age, pattern of breastfeeding, breastfeeding duration, breast health, maternal viral load and maternal immune status. Infants born to HIV infected mothers carry their mother's antibodies in their blood into the second year of life, even if the infants themselves are not infected. For this reason, standard HIV antibody tests cannot reliably confirm HIV infection in infants until after the maternal antibodies have disappeared. Tests that can diagnose pediatric HIV infection accurately during the first year of life include HIV-PCR, CD4/CD8 counts, P24 antigen tests, and viral cultures. PCR offers an effective tool to reliably diagnose HIV in a pediatric age group. Nineteen infants born by normal delivery to HIV-1 seropositive mothers were studied by PCR for the HIV1 env gene. Thirteen babies (68.5%) were negative whereas 6 babies were found to be positive (31.5%). Although PCR is one of the most useful tests for this clinical situation, it is not definitive. Therefore, PCR should be interpreted with caution and repeated at regular defined intervals, preferably lasting until the HIV antibody status of the infant is resolved.

Myasthenia gravis.

Myasthenia gravis is the prototype neuromuscular disease with immunological pathogenesis. The recognition and interpretation of the symptoms should be stressed as the diagnosis is initially achieved on clinical ground. Tests in the areas of immunology, electrophysiology and imaging further help the diagnosis, management and prognosis of the condition. The recent knowledge of immunology seems to point to variations in the immune abnormalities, but it remains to be seen whether the differences have clinical relevance. With the availability of intensive care units, the management of acute events in the myasthenic patients has improved considerably and the morbidity is reduced. Long term remissions are achievable in majority of patients, with supervised use of immunosuppression. In the modern times, the grave connotations of the name myasthenia gravis may be only rarely justified.

Remineralizing efficacy of a mineral enriched mouth rinse and fluoridated dentifrice on artificial carious lesions: an in vivo scanning electron microscopic study.

This comparative investigation was carried out to evaluate the remineralization potential on early artificial carious lesions under Scanning Electron Microscope (SEM) of a Mineral enriched mouthrinse and a fluoridated dentifrice using an in-vivo intra-oral removable appliance model. This findings revealed that the remineralization was found to have occurred in almost all the samples (in children) using non-fluoridated, fluoridated dentifrices as well as those using mineral enriched mouthrinse. However the qualitative analysis of the remineralization revealed that in case of non-fluoridated dentifrice group, the prismatic holes showed deposition of granular, variable sized particles with uneven distribution, while in fluoridated dentifrice group, deposits were found to have partially but more densely filled up the prism cores. In case of mineral enriched mouthrinse group these deposits were found to be in the form of amorphous globular precipitate.

Kayser-Fleischer like ring in autoimmune chronic active hepatitis.

Kayser-Fleischer ring is considered an important diagnostic sign of Wilson's disease. We report a 9 year old boy with autoimmune chronic active hepatitis who exhibited Kayser-Fleischer like ring.

Skeletal manifestations in beta-thalassaemia intermedia.

Thalassaemia intermedia with distressing complications is reported from India. An 11 year old boy presented with recurrent fractures since 6 years of age. Investigations revealed that he had multiple healed fractures of long bones, hypersplenism, iron overload and a red blood cell half life (t1/2) of 17 1/2 days. Splenectomy was planned.