Mycobacterium chelonae causing chronic wound infection and abdominal incisional hernia.

Mycobacterium chelonae is a rapidly growing mycobacterium that is found all over the environment, including sewage and tap water. They are important species associated with chronic non-healing wounds. We report a case in a 41 year old female patient who underwent multiple surgeries for an ovarian cyst, tuboovarian abscesses with peritonitis and a repair of an abdominal incisional hernia.

Transmission of zoonoses in xenotransplantation: Porcine endogenous retroviruses from an immunological and molecular point of view.

Background and Objectives: Pigs offer an unlimited source of xenografts for humans. The use of transplants from animal origin offers a potential solution to the limited supply of human organs and tissues. However, like many other mammalian species, pigs harbor porcine endogenous retrovirus (PERV), which are encoded in their genomic DNA and are assumed to have been integrated into the porcine germ line more than 7.6 × 106 years ago and showing that the age correlates with the time of separation between pigs and peccaries 7.4 × 106 years ago. The ability of the PERV to infect human cells in vitro has heightened safety concerns regarding the transmission of PERV to pig xenograft recipients. In this study, we detected PERV-AC recombinant virus in porcine genomic DNA that may have resulted from exogenous viral recombination. Infectious risk in xenotransplantation will be defined by the activity of PERV loci in vivo. We identified unique Haemophilus aegyptius III HaeIII gag restriction fragment length polymorphism (RFLP) profiles resulting from single nucleotide polymorphisms; these were found only in animals that produced human tropic PERV. Materials and Methods: Porcine tissues were analyzed using validated assays specific for PERV: polymerase chain reaction (PCR) (for PERV DNA), RT-PCR (for PERV RNA), cell culture, RFLP analysis, and sequence analysis. Conclusions and Interpretation : These findings have demonstrated that the presence of both DNA and RNA forms of porcine endogenous retrovirus in porcine tissues needs to be carefully considered when the infectious disease potential of xenotransplantation is being assessed.

Geographical location and age affects the incidence of parasitic infestations in school children.

Environmental factors affect the dissemination and distribution of intestinal parasites in human communities. To comprehend the prevalence of parasitic infestation and to examine whether geographical location and age also influence the prevalence of infection, fecal samples from 195 school children (rural = 95; male = 39; female = 56) (urban = 100; male = 60; female = 40) of five age groups ranging from 5 to 11 years in two different socio-economic zones (rural and urban) were screened for specific intestinal parasites using standard histological techniques. Percentage incidences of parasitic species found in fecal wet mounts and concentrates in rural children were Entamoeba coli (25.3%), Giardia lamblia (17.9%), Blastocystis hominis (14.7%), Entamoeba histolytica (4.2%), Iodamoeba butschlii (1.1%), Hymenolepis nana (1.1%) and Ascaris lumbricoides (1.1%). Whereas the percentage incidences among urban children were E. coli (26%), A. lumbricoides (21%), B. hominis (18%), G. lamblia (14%), T. trichiura (8%), I. butschlii (4%) and A. duodenale (1%). Such findings may be related to dietary differences, living conditions and the greater use of natural anti-helminthic medicinal plants in rural communities. These results are important for both epidemiological data collection and for correlating dietary differences to intestinal parasitic diseases. Aims: We chose to investigate whether geographical location and age affect the prevalence and distribution of intestinal parasites among school children from two separate regions (rural and urban) in areas surrounding, Chennai, Tamil Nadu, India. Settings and Design: A study of the prevalence of parasitic infestations was undertaken among primary school children, in rural and urban communities around Chennai, Tamil Nadu, India. Materials and Methods: Faecal sample collection, direct microscopic techniques, macroscopic examination and concentration techniques for identifying the parasites. Statistical analysis used: Percentage incidences of parasitic species found in faecal wet mounts and concentrates were done instead of statistical analyses. Results: Both macroscopic and microscopic examinations of faecal samples revealed that the overall percentage prevalence of parasite species encountered in rural children were Entamoeba coli (25.3%), G. lamblia (17.9%), B. hominis (14.7%), Entamoeba histolytica (4.2%), I. butschlii (1.1%), H. nana (1.1%), Ascaris lumbricoides (1.1%). The prevalence among urban children were E. coli (26%), A. lumbricoides (21%), B. hominis (18%), G. lamblia (14%), T. trichiura (8%), I. butschlii (4%) and A. duodenale (1%). Overall, comparative significant differences were noted between rural and urban children for E. histolytica (4.2 vs. 14%), G. lamblia (17.9 vs. 14%), A. lumbricoides (1.1 vs. 21%) and T. trichiura (0 vs. 8%), with the major difference being the much higher occurrence of A. lumbricoides and T. trichiura infections in urban children. Conclusions: One of the greatest challenges for healthcare professionals is the prevention and treatment of protozoal and helminthic parasitic infections. From our study we conclude that the prevalence of different pathogenic species of amoeba such as Entamoeba histolytica (4.2 vs. 0%) and G. lamblia (17.9 vs. 14%), (P value was equal to 1) was significantly higher among rural children compared to children from urban areas. In contrast, the prevalence of nematodes such as A. lumbricoides (21% vs. 1.1%), T. trichiura (8% vs. 0%) and A. duodenale (1%) was also significantly higher among rural children.

Detection of porcine rotavirus from tissue and faecal specimens.

Porcine small intestinal sub-mucosa is a cell-free collagen matrix that has demonstrated its ability as a scaffold material. Transplantation poses special hazards because grafted tissues and organs transmit pathogens efficiently, especially viruses. Rotavirus is thought to be confined to the intestine, causing acute diarrhoea. The purpose of this study was to evaluate the porcine intestinal tissue scaffold for Rotavirus and to study the incidence of this virus among pig herds. Only one isolate was successfully adapted to grow in cell line MA 104 from faecal samples. This isolate was further confirmed by reverse transcriptase polymerase chain reaction and sequence analysis.

Multiplex PCR for bla(CTX-M) & bla(SHV) in the extended spectrum beta lactamase (ESBL) producing gram-negative isolates.

BACKGROUND & OBJECTIVE: Phenotyping is commonly used for detection of extended spectrum beta lactamase (ESBL) production in gram-negative isolates. ESBLs are mainly coded for by three important genes, namely bla(TEM), bla(SHV) and bla(CTX-M). In this study we used a multiplex PCR as a rapid method to identify two common genes (bla(CTX-M) & bla(SHV)) responsible for extended spectrum beta lactamase production in members of Enterobacteriaceae family isolated from different clinical samples from a specialty hospital at Chennai. METHODS: A total of 260 non repetitive clinical isolates from 240 patients (some patients had more than one organism also), was selected for the study. Of these 33 were from sputum, 64 from urine, 46 from blood, 28 from pus aspirates, 58 from endotracheal secretions and 31 from other miscellaneous specimens. Phenotypic identification for ESBL production was confirmed by double disk synergy test (DDST) and phenotypic confirmatory double disk test (PCDDT) according to CLSI guidelines. Multiplex PCR for bla(CTX-M) and bla(SHV) was performed for the ESBL positive isolates. RESULTS: bla(SHV) like genes were found in 6 of 42 E.coli (14%), 7 of 46 Enterobacter species (15%), 28 of 62 Klebsiella species (45%) and bla(SHV) was not detected in any of the 50 isolates of non-fermenting gram-negative isolates. (Pseudomonas and Acinetobacter species) bla(CTX-M) like genes were found in 21 of 42 E. coli (50%), 13 of 46 Enterobacter species (28%), 25 of 62 (40%) Klebsiella species and 1 of 50 nonfermenting gram-negative bacilli (2%). INTERPRETATION & CONCLUSION: Our study demonstrated rapid detection of bla(SHV) and bla(CTX-M) in isolates belonging to Enterobacteriaceae and other non-fermenting clinical isolates using multiplex PCR. This genotypic method provided a rapid and efficient differentiation of ESBLs in the laboratory.

Sequence analysis of bla CTX-M-28 , an ESBL responsible for third-generation cephalosporin resistance in Enterobacteriaceae, for the first time in India.

The most common group of ESBLs not belonging to the bla TEM or bla SHV families were termed bla CTX-M , to highlight their ESBLs' greater activity against cefotaxime than against ceftazidime. The presence of nosocomial bla CTX-M-28 -producing Enterobacteriaceae strains has not been reported earlier in Indian hospitals. The sequences of bla CTX-M-28 gene from cephalosporin-resistant Enterobacteriaceae were analyzed. The structural gene encodes a 290 amino-acid protein, which is most related to the bla CTX-M beta-lactamases. The conserved K-T-G was identified in the bla CTX-M-28 protein sequence, but significantly, two point mutations (N-->T) and (F-->S) were identified in the Y-G-N- and S-T-F-K-conserved motifs respectively. These point mutations were seen in all the three sequenced isolates.

Chronic postoperative wound infection caused by Myocobacterium fortuitum complex.

Mycobacterium fortuitum in a rapidly growing atypical mycobacteia, sometimes associated with nosocomial infections in human. These infections are often difficult to identify; and treat even after indentification. We report here a case of chronic post operative wound infection due to M. fortuitum.

Chryseobacterium meningosepticum--an uncommon pathogen causing adult bacterial meningitis.

Chryseobacterium meningosepticum is an uncommon pathogen causing meningitis. We report a case of adult meningitis caused by chryseobacterium meningosepticum in an 88 year old woman. Immunosuppression due to old age, diabetes mellitus and history of hypertension of 20 years duration were the concomitant factors. chryseobacterium meningosepticum was isolated both from the cerebrospinal fluid and blood cultures. This organism was sensitive to quinolones, rifampicin and resistant to many antibiotics commonly used for empiric therapy for meningitis.

Homograft valve bank: our experience in valve banking.

BACKGROUND: A cardiac homograft valve bank with cryopreservation facility was established at the Institute of Cardiovascular Diseases, Madras Medical Mission, Chennai in July 1995. METHODS AND RESULTS: During the last 7 1/2 years of its existence, from July 1995 to March 2003, 588 hearts were processed. The valves harvested were 390 aortic, 400 pulmonary and 39 others including mitral valve, aortic conduits, pericardium etc.; 176 (29.9%) hearts were discarded for various reasons which included failure to sterilize, HBV, HIV, HCV, treponema pallidum hemagglutination test positivity, atheromatous/fatty streaks, incompetent valves, and dissection mistakes. The valves were sterilized using an antibiotic cocktail of vancomycin, amikacin, streptomycin, cefotaxime and amphotericin B in Hank's balanced salt solution. Of the 585 valves issued for clinical use, 247 were aortic, 323 pulmonary and 15 others (mitral valve, pericardium, conduits). Gram negative bacilli were the predominant contaminants from the hearts during the first half (July 1995 to February 1999) and gram positive organisms were the predominant contaminants during the later half (March 1999 to March 2003) of the study period. A variety of fungal contaminants like candida, aspergillus, penicillium and other fungi were also isolated from the homograft hearts at procurement. The valves were used most commonly for Rastelli procedure/right ventricular-pulmonary artery conduit (48.71%) followed by Ross procedure (23.41%). The other procedures were aortic valve replacement (6.15%), truncus repair (5.81%), unifocalization with conduit repair (6.49%), aortoplasty (0.512%), left ventricular-pulmonary artery conduit (0.512%), pulmonary valve replacement (0.512%), aneurysm repair (0.34%), Norwood repair (0.34%), mitral valve replacement (0.17%) and other procedures (7%). CONCLUSIONS: We have established a viable and functioning cardiac homograft valve bank to suit Indian conditions and till date, have issued 585 homograft valves for clinical use.

Nocardia asteroides mediastinitis complicating coronary artery bypass surgery.

A 63 years diabetic male was admitted with mediatinitis and sternal dehiscence. Nocardia asteroides sensu stricto Type VI was isolated from the mediastinal tissue and fluid during debridement. Prompt surgical intervention and treatment with ofloxacin both intravenously and later orally led to the cure.

HLA expression in aortic and pulmonary homografts: effects of cryopreservation.

BACKGROUND: The present study was undertaken to find out the HLA allo-antigens on cardiac homografts. METHODS AND RESULTS: One pulmonary and eight aortic homografts were studied for the presence of major HLA class I and class II antigen expression. Cadaveric hearts were procured from the mortuary and kept in Hank's balanced salt solution with antibiotics at 4 degrees C. Bits were taken from the conduits and valves every 24 hours for 14 days during storage and snap-frozen using liquid nitrogen. A total of 1368 sections were made using a cryostat. These sections were stained using 4 monoclonal antibodies: BLA class I (MO736), class II HLA-DR (MO746), CD45 (MO701), and endothelial stain (MO616). All monoclonals were procured from DAKO. Class I antigen molecules could be demonstrated on the endothelial surface of the vessel wall from day 1 to day 4 to 5 of storage. They stained weaker and could not be demonstrated after day 10 of storage. Class I antigen molecules were positive in very fresh valves and by day 5-6 could not be seen on the valve surface. Class II (HLA-DR) antigen expression was present in the subendothelial layer from day 1 to day 12-14 of storage. They could also be demonstrated in valves and conduits released after cryopreservation. These class II staining cells were also stained by CD45 monoclonal antibody and hence could be macrophages, histiocytes or leucocytes. The endothelium was very well demonstrated in the vessel walls from day 1 to day 12-14 of storage; it could only be seen in very fresh valves. Storage in the liquid medium and sterilization procedures led to loss of endothelial lining of the valves. After cryopreservation and thawing, class I antigen molecules could not be demonstrated on the valves and conduits. Class II antigen molecules and CD45-stained cells continued to be demonstrated in the subendothelial layer and the valve matrix. The endothelium was intact in the vessel wall after cryopreservation and thawing, but could not be seen in the released valves. CONCLUSIONS: Allograft aortic and pulmonary conduits and valves are immunogenic, and HLA-ABC and HLA-DR antigen molecules can be demonstrated on different components of the vessel wall and valve leafets.

Trichosporonosis due to Trichosporon beigelli in two hospitalized patients.

Trichosporon beigelli has been reported to cause invasive disease such as blood stream infection in severely immunocompromised patients. Two cases of urinary and disseminated trichosporonosis by Trichosporon beigelli in hospitalized patients, with predisposing factors such as prolonged hospital stay, continuous urinary catheterization and broad spectrum antibiotics are reported.

A comparative study of the intestinal parasites prevalent among children living in rural and urban settings in and around Chennai.

A comparative analysis of the various intestinal parasites detected among children attending schools was carried out in a rural and urban location in and around Chennai. A total of 324 stool samples were examined by routine microscopy using normal saline and Lugol's iodine preparation as well as by saturated sodium chloride flotation technique. All suspicious samples were subjected to zinc sulphate concentration technique as well as modified Ziehl Neelson stain and Trichrome stains to identify the other uncommon intestinal parasites. Out of 125 specimens tested from the rural location, the overall prevalence of intestinal parasites was 91%. Ascaris lumbricoides was the most common helminthic parasite detected (52.8%) followed by Trichuris trichura (45.6%), Ancylostoma duodenale (37.6%), Strongyloides stercoralis (3.2%) and Hymenolepis nana (1.6%). Giardia lamblia was the most common protozoan parasite detected (16%), followed by Entamoeba histolytica (4%). In contrast under urban settings, out of the 199 stool specimens tested the positivity rate was 33%. Giardia was the most common parasite detected (22.6%) followed by Entamoeba histolytica (10.6%). All other intestinal parasites such as T. trichura (2.01%), H. nana (1.01%) and A. lumbricoides (0.50%) were found to have much lower prevalence in comparison to the rural area tested. Enterobius vermicularis (0.50%) was also detected. Ancylostoma duodenale and Strongyloides stercoralis were not encountered at all in the urban setting studied.

Prospective evaluation of the risk of bacteremia induced by transesophageal echocardiography.

BACKGROUND: The incidence of bacteremia induced by transesophageal echocardiography is controversial in the Indian population. This study aimed to find out the occurrence of bacteremia following transesophageal echocardiography. METHODS AND RESULTS: Between February 2000 and January 2001, 47 patients (26 males and 21 females) were enrolled for the study. Their ages ranged from 13 to 61 years (mean: 35 +/- 11.4 years). Patients with prosthetic valves, suspected infective endocarditis and those on antibiotics were excluded. For each procedure, two sets of blood cultures were obtained immediately before and after the procedure. For each blood culture, 10 ml of blood was evenly inoculated into brain-heart infusion broth and biphasic infusion medium and incubated for 7 days. Transesophageal echocardiography was carried out under oropharyngeal anesthesia (xylocaine gel and spray). Two blood cultures taken before the procedure were positive and excluded from the final analysis. Of the remaining 45 patients whose preprocedure blood cultures were sterile, 6 samples (13.3%) were positive after the procedure diphtheroids in 3, micrococci in 2 and aerobic spore formers in 1. CONCLUSIONS: This study demonstrates that the incidence of bacteremia related to transesophageal echocardiography is not insignificant, as reported in previous studies. Though routine antibiotic prophylaxis before transesophageal echocardiography is not advocated, it should be recommended in high-risk patients such as those with prosthetic valves, multivalvular involvement or those with a past history of infective endocarditis.