An experimental study of phage mediated bactericidal selection & emergence of the El Tor Vibrio cholerae.

Background & objectives: Factor causing the elimination of the classical biotype of Vibrio cholerae O1, and its replacement by the El Tor biotype causing the 7th cholera pandemic are unclear. Possible ability of the El Tor strains to adapt better than the classical strains to undefined environmental forces have been largely implicated for the change. Here we describe an environmental bacteriophage designated JSF9 which might have contributed to the range of factors. Methods: Competition assays were conducted in the infant mice model and in microcosms between representative El Tor and classical biotype strains in the absence or in the presence of JSF9 phage. Results: The JSF9 phage was found to kill classical strains and favour enrichment of El Tor strains, when mixtures containing strains of the two biotypes and JSF9 phage were subjected to alternate passage in infant mice and in samples of environmental water. Spontaneous derivatives of the classical biotype strains, as well as transposon mutants which developed resistance to JSF9 phage were found to be defective in colonization in the infant mouse model. Interpretation & conclusions: These results suggest that in addition to other factors, the inherent ability of El Tor biotype strains to evade predation by JSF9 or similar phages which kill classical biotype strains, might have enhanced the emergence of El Tor strains as the predominant pandemic biotype.

Tonsillectomy as a short stay procedure: experience at Nishtar Hospital, Multan

To emphasize that tonsillectomy is no more a procedure which requires longer stay in the hospital. A prospective study was undertaken to evaluate the incidence and severity of complications particularly the reactionary haemorrhage relative to the time of the surgery and to determine the safe postoperative time for discharge. Setting: ENT Units, Nishtar Hospital, Multan. One thousand cases of tonsillectomy performed during the last three years from July 1st 1995 to June 1998. Over a period of 3 years one thousand cases of tonsillectomy were studied with age range from 4 to 32 years, with male to female ratio 2:1. Reactionary haemorrhage was the more troublesome complication and majority of the sufferers belonged to the paediatric age group. The overall incidence of posttonsillectomy haemorrhage was 2%. All cases responded very well to conservative measures, only 0.7% cases needed surgical intervention. It was noted that all cases of reactionary haemorrhage occurred within first 2-6 hours after surgery. The study reveals that the incidence of reactionary haemorrhage and other complications is very low and time period is initial six hours so the patients may be sent home safely after short stay in the hospital

Malignant otitis externa

Malignant external otitis is a serious pseudomonas infection of the external ear which when untreated may extend towards the base of the skull. To find out the results of conservative treatment and compare it with previous studies. To diagnose this condition at its earlier stage to improve the prognosis. Design: Case study. Setting: ENT Department Punjab Medical College Hospital Faisalabad. Period: Mar 86 to March 1996. Subjects: Fifteen patients, 9 females, 6 males between the ages of 20-26 years, all diabetics presented during the period Mar 86 to Mar 1996. Diagnosis was based upon clinical findings and positive pseudomonas aeruginosa in culture of ear swab. Local debridement, cleansing local drops and systemic use of aminoglycoside with third generation cephalosporin in resistent case used for treatment. 9 Females and 6 Males all between 20-26 years of age presented with pain, discharge, edema, granulations and fever. All were confirmed diabetics and ear swab revealed pseudomonas aeruginosa. Local cleansing with local and systemic aminoglycoside was sufficient in 10 cases but in 5 cases Ceftazidime was also added. Antibiotics were continued 4 weeks after control of symptoms. 13 patients [86.6%] cured without any long term complications, 2 patients [13.3%] died due to MEO. Malignant otitis externa through a dangerous infection can be cured on conservative treatment if diagnosed early