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Biomedical subjects

P Garg

Publications and source records attributed to P Garg.

At least 55 records · Page 3Linked to original sources
PubMed2000

Emergence of Vibrio cholerae O1 biotype El Tor serotype Inaba from the prevailing O1 Ogawa serotype strains in India.

The toxigenic Inaba serotype of Vibrio cholerae O1 biotype El Tor reappeared in India in 1998 and 1999, almost 10 years after its last dominance in Calcutta in 1989. Extensive molecular characterization by ribotyping, restriction fragment length polymorphism, and pulsed-field gel electrophoresis indicated that recent Inaba strains are remarkably different from the earlier Inaba strains but are very similar to the prevailing V. cholerae O1 Ogawa El Tor biotype strains. The antibiograms of the Inaba strains were also similar to those of the recent V. cholerae Ogawa strains. These V. cholerae O1 Inaba strains appear to have evolved from the currently prevailing Ogawa strains and are likely to dominate in the coming years.

Anti-Bacterial Agents↗
PubMed2000

Pandemic spread of an O3:K6 clone of Vibrio parahaemolyticus and emergence of related strains evidenced by arbitrarily primed PCR and toxRS sequence analyses.

Vibrio parahaemolyticus O3:K6 strains responsible for the increase in the number of cases of diarrhea in Calcutta, India, beginning in February 1996 and those isolated from Southeast Asian travelers beginning in 1995 were shown to belong to a unique clone characterized by possession of the tdh gene but not the trh gene and by unique arbitrarily primed PCR (AP-PCR) profiles (J. Okuda, M. Ishibashi, E. Hayakawa, T. Nishino, Y. Takeda, A. K. Mukhopadhyay, S. Garg, S. K. Bhattacharya, G. B. Nair, and M. Nishibuchi, J. Clin. Microbiol. 35:3150-3155, 1997). Evidence supporting a hypothesis that this clone emerged only recently and is spreading to many countries was obtained in this study. Of 227 strains isolated in a hospital in Bangladesh between 1977 and 1998, only 22 strains isolated between 1996 and 1998 belonged to the new O3:K6 clone (defined by the serovar, the tdh and trh typing, and AP-PCR profiles). The O3:K6 strains isolated from clinical sources in Taiwan, Laos, Japan, Thailand, Korea, and the United States between 1997 and 1998 were also shown to belong to the new O3:K6 clone. The clonality of the new O3:K6 strains was also confirmed by analysis of the toxRS sequence, which has been shown to be useful for phylogenetic analysis of the members of the genus Vibrio. The toxRS sequences of the representative strains of the new O3:K6 clone differed from those of the O3:K6 strains isolated before 1995 at least at 7 base positions within a 1,346-bp region. A new PCR method targeted to 2 of the base positions unique to the new O3:K6 clone was developed. This PCR method could clearly differentiate all 172 strains belonging to the new O3:K6 clone from other O3:K6 strains isolated earlier. One hundred sixty-six strains belonging to 28 serovars other than O3:K6 were also examined by the new PCR method. The tdh-positive and trh-lacking strains that belonged to the O4:K68 and O1:K untypeable serovars and were isolated in three countries and from international travelers beginning in 1997 gave positive results. The AP-PCR profiles of these strains were nearly identical to those of the new O3:K6 clone, and their toxRS sequences were 100% identical to that of the new O3:K6 clone. The results suggest that these strains may have diverged from the new O3:K6 clone by alteration of the O:K antigens. In conclusion, this study presents strong evidence for the first pandemicity in the history of V. parahaemolyticus and reports a novel toxRS-targeted PCR method that will be useful in epidemiological investigation of the cases associated with the current pandemic spread.

Bacterial Proteins↗
PubMed2000

Corneal ulceration in the elderly in Hyderabad, south India.

AIMS: To report demographic, microbiological, therapeutic, anatomical, and visual results of corneal ulceration in the elderly patients seen at a tertiary eye care centre in south India. METHODS: 102 consecutive cases of microbial keratitis in patients 65 years and older were studied. Inclusion criteria were: (i) presence of corneal stromal infiltrate upon slit lamp examination; and (ii) microbiological evaluation of corneal scrapings for suspected microbial keratitis. RESULTS: The principal predisposing factors identified in this study were ocular disease (38.2%), previous ocular surgery in the same eye (29.4%), trauma (17.6%), and severe systemic disease (16.7%). Contact lens wear was associated with only two cases (2.0%). 99 organisms were isolated in cultures of corneal scrapings from 74 (72.5%) of the 102 cases. Staphylococcus epidermidis (31.1%), filamentous fungi (25.7%), and Streptococcus pneumoniae (13.5%) were the most common isolates. 12 eyes (11.8%) required surgery, 15 (14.7%) eventually required evisceration, and nine (9.6%) of the 94 followed patients achieved an unaided vision of 20/60 or better at last follow up. CONCLUSIONS: This work represents the largest recent single centre study on (non-viral) microbial keratitis in the elderly, its management, and outcomes of therapy. While the predisposing factors differ from those of general population, the spectrum of microbes responsible for keratitis in the elderly appears to reflect the local microbial flora rather than a predilection for elderly patients. Delay in diagnosis and systemic conditions associated with advancing age probably contribute to poorer outcome from therapeutic measures.

Acanthamoeba Keratitis↗
PubMed2000

Patient characteristics, diagnosis, and treatment of non-contact lens related Acanthamoeba keratitis.

AIM: To review the clinical characteristics, diagnosis, and visual outcome in patients with non-contact lens related Acanthamoeba keratitis and compare the findings with reported series of contact lens associated Acanthamoeba keratitis. METHODS: Medical and microbiology records of 39 consecutive patients with a diagnosis of Acanthamoeba keratitis, at a tertiary eyecare centre in India between January 1996 and June 1998, were analysed retrospectively. RESULTS: A majority of the patients presented with poor visual acuity and large corneal stromal infiltrates (mean size 38.20 (SD 26. 18) mm). A predisposing factor was elicited in 19/39 (48.7%) patients (trauma 15, dirty water splash three, leaf juice one). None of the patients had worn contact lenses. Most patients (26/39 (66. 6%)) came from a low socioeconomic background. Complaint of severe pain was not a significant feature and radial keratoneuritis was seen in 1/39 (2.5%) patients. A ring infiltrate was present in 41.1% of cases. A clinical diagnosis of fungal keratitis was made in 45% of the patients before they were seen by us. However, all patients were diagnosed microbiologically at our institute based on demonstration of Acanthamoeba cysts in corneal scrapings (34/39) and/or culture of Acanthamoeba (34/39). Treatment with biguanides (PHMB, 15/38 (39.4%), PHMB with CHx, 23/38 (60.5%), one patient did not return for treatment) resulted in healing with scar formation in 27 out of 31(87.0%) followed up patients (mean time to healing 106.9 days). Overall visual outcome was poor with no statistical difference between cases diagnosed within 30 days (early) or 30 days after (late) start of symptoms. The visual outcome in cases requiring tissue adhesive (five) and keratoplasty (three) was also poor. CONCLUSIONS: This is thought to be the largest series of cases of Acanthamoeba keratitis in non-contact lens wearers. In such cases, the disease is advanced at presentation in most patients, pathognomonic clinical features are often not seen, disease progression is rapid, and visual outcome is usually poor. Possible existence of Acanthamoeba pathotypes specifically associated with non-contact lens keratitis and unique to certain geographical areas is suggested.

Acanthamoeba Keratitis↗
PubMed2000

Cluster-analysis & patterns of dissemination of multidrug resistance among clinical strains of Vibrio cholerae in Calcutta, India.

BACKGROUND & OBJECTIVES: Antimicrobial resistance among Vibrio cholerae has been monitored for several years in Calcutta. To investigate the changing trends in multidrug resistance (MDR) among different serogroups of V. cholerae and to perform software assisted cluster analysis the current study was undertaken. METHODS: Strains isolated from patients with cholera and "cholera-like" diarrhoea admitted in the Infectious Diseases Hospital, Calcutta were analysed. Eight hundred and forty V. cholerae strains isolated from 1992 through 1997 were tested for susceptibility to 11 antibiotics. Cluster analysis was done using SPSS software. RESULTS: Most of the strains exhibited MDR with fluctuating trends as the resistance profile diverged each year. A total of 119 different resistance profiles exhibited by V. cholerae O1, O139 and non-O1, non-O139 serogroups were analysed by cluster combination method. During 1993 and 1994, 53 per cent of V. cholerae O139 and 82 per cent of V. cholerae O1 serogroups, respectively, exhibited maximal number of new resistance patterns. The frequency of new resistance patterns among V. cholerae non-O1, non-O139 was constantly high (33-47%) during 1995 to 1997. INTERPRETATION & CONCLUSIONS: With a few exceptions, preponderance of the resistance profiles was generally not confined to any serogroup. The cluster analysis depicted dissemination of some of the resistance patterns commonly found among V. cholerae non-O1, non-O139 belonging to different serogroups to the O139 serogroup in the succeeding years. In this study we have shown that the V. cholerae strains are resistant to several antibiotics with constant change in the MDR profiles. It is imperative to define the susceptibility pattern of the strains to determine the effective drug of choice for the treatment of cholera.

Cluster Analysis↗
PubMed2000

Percussion of Traube's space--a useful index of splenic enlargement.

OBJECTIVE: To evaluate the sensitivity and specificity of palpation and percussion for splenic enlargement, as the accuracy of many of the clinical maneuvers we perform remains largely unstudied. METHODS: One hundred cases were selected at random from medical wards, and splenic enlargement was assessed by palpation and percussion of the Traube's space (Barkuns method), which was confirmed by the ultrasonography of the abdomen. The results of the various tests were tabulated and assessed statistically. RESULTS: 1) Performance of Traube's space percussion shows 24 true positive and 48 true negative cases, the test thus had an overall sensitivity of 67% and specificity of 75%. It was also found that the BMI of the false negative cases was significantly higher (29.43 Kg/m2). 2) Palpation as a diagnostic maneuver had a high specificity of 96.87% along with high false negative rate with overall low sensitivity of 44.44%. 3) Interpolation of findings of Traube's space percussion and palpation showed that maximum clinical utility could be achieved when both percussion and palpation were positive. CONCLUSION: Percussion of the Traube's space is a useful clinical screening test for splenomegaly, with a sensitivity of 67% and specificity of 75%, as compared to palpation (sensitivity of 44.44% and specificity of 96.87%). And maximum clinical utility is achieved when both percussion and palpation are combined.

Adult↗
PubMed2000

Keratocyte loss in Acanthamoeba keratitis: phagocytosis, necrosis or apoptosis?

PURPOSE: Pathogenesis of Acanthamoeba keratitis involves breakdown of epithelial barrier, stromal invasion by Acanthamoeba, loss of keratocytes, inflammatory response and finally stromal necrosis. The loss of keratocytes, believed to be due to the phagocytic activity of the parasite, occurs disproportionate to and independent of the parasite load, thereby suggesting additional modes of cell loss. To test our hypothesis that the loss of keratocytes in Acanthamoeba keratitis is due to apoptosis, we did both histology and histochemistry on the corneal tissues. METHODS: Routine Haematoxylin and Eosin, Gomori's Methenamine Silver and Periodic acid Schiff stained sections of five corneal tissues from penetrating keratoplasty and eviscerated eyes were reviewed. TUNEL staining was done for morphological detection of apoptosis in three cases, using formalin-fixed, paraffin-processed tissues. RESULTS: Histological changes were epithelial ulceration, loss of keratocytes in all layers, inflammation in anterior two-thirds of the stroma with necrosis, and deeper quiet stroma. Acanthamoeba trophozoites were found in the anterior stroma while the cysts were more in the deeper stroma, with minimal or no inflammatory response. TUNEL staining was positive in keratocytic nuclei in all layers. CONCLUSIONS: This study demonstrates that one of the modes of keratocyte loss in Acanthamoeba keratitis is by apoptosis, possibly in addition to the necrotic process and phagocytic activity of the parasite. The death of inflammatory cells also appears to be mediated by apoptosis.

Acanthamoeba↗
PubMed1999

Omentum autotransplantation in thromboangiitis obliterans: report of three cases.

Thromboangiitis obliterans (TAO), also known as Buerger's disease, is an important cause in India of chronic arterial occlusion of the limbs. The current modalities of therapy do not provide adequate relief to a large number of these patients. An omentum autotransplantation to the lower limbs was performed in three patients as a limb salvage procedure. The initial results with up to a year of follow-up are so far encouraging.

Adult↗
PubMed1999

Ciprofloxacin-resistant Pseudomonas keratitis.

OBJECTIVE: To determine ciprofloxacin resistance of corneal isolates of Pseudomonas and to review the clinical response to topical therapy in cases of ciprofloxacin-resistant Pseudomonas keratitis, where medical therapy was begun with 0.3% ciprofloxacin. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Medical and microbiology records of 141 culture-proven cases of Pseudomonas keratitis, examined between January 1991 and June 1998, were reviewed retrospectively. METHODS: All isolates of the Pseudomonas species from corneal scrapings were tested for their susceptibility to routinely used antibiotics by the Kirby-Bauer disc-diffusion method. The minimum inhibitory concentration of ciprofloxacin was determined by the agar-dilution method for most of the isolates found resistant to ciprofloxacin. Clinical response to initial therapy with 0.3% ciprofloxacin was determined in cases of keratitis caused by ciprofloxacin-resistant Pseudomonas. MAIN OUTCOME MEASURES: Resistance of Pseudomonas isolates to ciprofloxacin and clinical response to initial therapy with 0.3% ciprofloxacin. RESULTS: By use of the in vitro antimicrobial susceptibility test, 22 cases of keratitis caused by ciprofloxacin-resistant Pseudomonas were identified. The minimum inhibitory concentration of ciprofloxacin for these isolates was > or =16 microg/ml (mean = 43 microg/ml). Gentamicin resistance occurred in 63.6% of isolates also, but 90.9% ciprofloxacin-resistant isolates were susceptible to amikacin. Fifteen (76.7%) of 19 patients who initially received ciprofloxacin did not show any clinical improvement even after 3 days of intensive medical therapy. The infiltrate resolved in all 8 cases where the antibiotic therapy was modified on the basis of susceptibility test. Four eyes were subjected to penetrating keratoplasty, and three were eviscerated following failure of treatment with ciprofloxacin. CONCLUSION: True resistance to ciprofloxacin is emerging in ophthalmology even among Pseudomonas isolates; therefore, the empiric treatment of infectious keratitis with ciprofloxacin monotherapy must be critically reviewed at this time.

Adolescent↗
PubMed1999

In vitro susceptibility of bacterial keratitis pathogens to ciprofloxacin. Emerging resistance.

OBJECTIVE: To examine in vitro susceptibility of bacterial keratitis pathogens to ciprofloxacin. DESIGN: Retrospective review. PARTICIPANTS: The authors examined in vitro susceptibility of 1558 corneal isolates from 1303 patients with culture-proven bacterial keratitis seen at the LV Prasad Eye Institute in Hyderabad, India, during the 6-year period between March 1, 1991, and June 30, 1997. RESULTS: Of 1558 corneal isolates, 478 (30.7%) were not sensitive to ciprofloxacin. Among the isolates, 355 (32.5%) of the 1091 gram-positive cocci were not sensitive to ciprofloxacin, and 2 (10%) of the 20 gram-positive bacilli, 22 (13.3%) of the 165 gram-negative organisms, and 99 (35.1%) of the 282 Actinomycetes and related organisms were not sensitive to ciprofloxacin. Results from chi-square for trends analysis showed a trend of significantly increasing ciprofloxacin insensitivity in bacteria between 1992 and 1997 (P = 0.011). CONCLUSION: This is the first report of significantly increasing ciprofloxacin insensitivity among corneal pathogens. Although the lowered cost and convenience of dispensing a single, commercially available antibiotic such as ciprofloxacin in the initial treatment of bacterial keratitis is desirable, the emergence of ciprofloxacin resistance is a significant finding in this series, and the clinician should proceed with caution in the initial empiric treatment of bacterial keratitis with ciprofloxacin.

Anti-Infective Agents↗
PubMed1999

Treatment outcome of Moraxella keratitis: our experience with 18 cases--a retrospective review.

PURPOSE: To analyze the clinical presentation, predisposing risk factors, in vitro antimicrobial susceptibility, and especially the outcome of therapy of Moraxella keratitis. METHODS: Retrospective review of 18 culture-proven cases of Morarella keratitis. RESULTS: Morarella keratitis was associated with Hansen's disease, uncontrolled diabetes mellitus, herpes zoster ophthalmicus, and chickenpox of the recent past and severe protein energy malnutrition. Other associated ocular conditions included lagophthalmos, blepharitis, steroid therapy, corneal degeneration, and scleritis. In four patients, no systemic or ocular predisposing factors could be identified. Three patients presented with an indolent peripheral, anterior stromal infiltrate while the remaining patients showed a central or paracentral ulceration with or without hypopyon. Moraxella species was the only pathogen isolated in 11 cases, whereas mixed infection was seen in seven cases. All isolates were sensitive to ciprofloxacin. Eight of 18 strains of Moraxella were resistant to cefazolin. All 14 eyes for which the follow-up data were available responded to medical treatment alone. CONCLUSIONS: Although considered to be associated with poor outcome, our experience suggests that a favorable outcome can be expected in Moraxella keratitis. Cefazolin resistance (as seen in our series) may pose a problem and, hence, monitoring of antimicrobial susceptibility would be beneficial. In view of cefazolin resistance, ciprofloxacin monotherapy appears to be an effective method in the medical management of these cases.

Adolescent↗
PubMed1998

Neonatal scrotal faecal fistula.

Incarceration of a congenital inguinal hernia, if untreated promptly, can result in dreaded complications like faecal fistula. We report one neonate who presented with a scrotal faecal fistula due to late presentation.

Anastomosis, Surgical↗
PubMed1998

Mycobacterium chelonei masquerading as Corynebacterium in a case of infectious keratitis: a diagnostic dilemma.

PURPOSE: The diagnosis of Mycobacterium keratitis can often be missed both clinically and microbiologically and this report highlights one such case. METHODS: Review of medical and microbiological records. RESULTS: We report a case of Mycobacterium keratitis in a 25-year-old man that was misdiagnosed as Corynebacterium keratitis at initial presentation. Presence of partially stained and beaded bacilli in a Gram-stained smear of repeat corneal scrapings raised the suspicion of an unusual organism. Ziehl-Neelsen staining of the decolorized Gram-stained smear and subculture on Löwenstein-Jensen medium helped us to establish the diagnosis. CONCLUSIONS: A high degree of suspicion needs to be maintained, especially in cases in which (a) there is a history of corneal trauma involving a foreign body, (b) the Gram-stained smear of corneal scrapings shows a paucity of organisms and the presence of partially stained and beaded bacilli in the presence of confluent growth of colonies resembling those of Corynebacterium, and (c) a typical corneal feature like "cracked windshield" stromal lesion is seen, to avoid such a misdiagnosis. Inclusion of a Löwenstein-Jensen culture at the initial presentation, especially when the clinical presentation is atypical, as seen in this case, will lead to an early diagnosis.

Adult↗
PubMed1998

Molecular epidemiology of reemergent Vibrio cholerae O139 Bengal in India.

We report the prevalence of the O139 serogroup in Calcutta, India, after its reemergence in August 1996 and the spread of the reemerged clone to other parts of the country by using previously established molecular markers. Phenotypically, the reemerged Vibrio cholerae O139 displayed a difference compared to those that appeared in late 1992 and 1993 in that the current O139 strains are sensitive to co-trimoxazole. Ribotyping with the enzyme BglI produced two rRNA restriction patterns in the O139 strains isolated after August 1996, and these patterns were identical to those exhibited by strains of O139 isolated in 1992. Three clones of V. cholerae O139 are currently prevailing in the country, with strains exhibiting three bands after HindIII digestion and hybridization with a ctxA probe being dominant. The reemergence of V. cholerae O139 in Calcutta after a 32-month quiescent period reestablishes the O139 serogroup as an entity which is likely to play a crucial role in the temporal antigenic variations among the serogroups of V. cholerae causing cholera.

Bacterial Typing Techniques↗
PubMed1998

Multiple diverticula of gall bladder.

Diverticula of the gall bladder are of no clinical significance unless associated with stones. Isolated location on Hartmann's pouch, body or neck have been explained on disordered embryogenesis but diffuse location all over the gall bladder is difficult to explain. We report a patient in whom multiple gall bladder diverticula were associated with a stone in the common bile duct.

Adult↗
PubMed1998

Gall bladder carcinoma presenting as liver abscess.

Perforation of malignant gall bladder resulting in liver abscess and presenting as pyrexia of unknown origin is rare. We report a patient who was diagnosed at surgery, which was undertaken with a diagnosis of liver abscess on CT scan.

Adenocarcinoma↗