Phage Types of multidrug resistant Salmonella species in a rural area of Maharashtra ,

Objective: The aim of the present study is to know Phage typing and antimicrobial susceptibility pattern of Salmonella species. Methods: A total of 32 Salmonella species isolated from stool and blood specimen were included in the study. They were sent for phage typing to Lady Hardinge Medical College, New Delhi. Antimicrobial susceptibility was done by using Kirby Bauer disc diffusion method. Results: Majority of Salmonella typhi belongs to phage type E1 and biotype I. Decreased susceptibility of the isolate was observed to Ampicillin, Cotrimoxazole, Cephalexin and Gentamicin. Majority of the isolates were sensitive to Ciprofloxacin. Conclusion: Predominant phage type was E1. The antibiotic sensitivity pattern is changing and resistant cases are emerging due to inappropriate use of antibiotics.


Introduction
Prolonged pyrexial illness is still a major cause of anxiety to the medical community. 1Salmonella infections are frequent throughout the world and are a major health concern particularly to India.In India, enteric fever is endemic in many parts. 2nfection is caused by substandard water supply and sanitation.Increasing reports of multiple drug resistant (MDR) Salmonella strains from different parts of the country demands constant surveillance. 3,4acteriophage typing is the standard method for subdividing S. typhi into epidemiologically significant subtypes.
The present study was undertaken at a rural medical college to determine the prevalent phage types and biotypes of Salmonella serotypes isolated during one year period and antibiotic sensitivity pattern of it.

Material &Methods
A total of 32 Salmonella were isolated from blood and stool samples during one year period.Samples were cultured and processed as per the standard methods and Salmonella species were identified by the biochemical reactions and confirmed by specific serotyping procedures. 5tibiotic sensitivity pattern of isolated Salmonella was studied by Kirby Bauer disc diffusion method. 6hage typing and biotyping was carried out by the National Phage typing Center, Lady Hardinge Medical College, New Delhi.

Results
Thirty two Salmonella were isolated over two year's period.Out of 32 patients, 20 were Salmonella typhi and 12 were Salmonella paratyphi A. Phage types of Salmonella species is given in table1.The antibiogram of it is shown in table 2. Majority of the isolates were sensitive to Ciprofloxacin.There was an increase in resistance to Ampicillin, Cotrimoxazole and Cephalexin.

Discussion
The spectrum of Salmonella infection has widened over the last few years due to acquisition of mul-tidrug resistance to conventional drugs.Besides causing self limiting clinical manifestations of gastroenteritis, Salmonellae are also responsible for invasive disease including enteric fever (typhoid and paratyphoid fever) bacteremia, septicemia and extraintestinal focal sepsis.
In the present study a total of 32 salmonella strains were isolated.Salmonella typhi was the commonest followed by Salmonella paratyphi A. The commonest phage type of S.typhi was E1 and the biotype was I followed by phage type A (table I).2][13] The phage O which has also been commonly reported was absent in our study. 14,15The difference is probably due to introduction of the new phage types in the area.
Of the 12 S. paratyphi A strains, all were untypable.Multidrug resistance showed an alarming rise in our study.[18][19] In our study majority of the isolates were sensitive to ciprofloxacin (87.5%) followed by chloramphenicol (75%).In the present study it has been found that the large numbers of isolates were resistant to cotrimoxazole (90.62%), erythromycin (71%), ampicillin (65.62%), penicillin (65.62%), norfloxacin (56.25%), gentamicin (53.15%), amikacin (43.75%) and cephalexin (40.62%) in the decreasing order of frequency.Ampicillin and chloramphenicol have long been the first line of treatment for invasive Salmonella infections but these drugs can no longer be recommended in developing countries.Indiscriminate use of the drug and acquisition of plasmid mediated R factor has led to the development of resistance to Salmonella. 20ternative therapy includes Fluoroquinolones and cephalosporin.Quinolones are preferred for most Salmonella infections but cephalosporin may be better in neonatal meningitis.Empiric therapy with ciprofloxacin had led to decrease in the frequency of chloramphenicol resistance, but resistance to ciprofloxacin is now recognized. 21,22 our study ciprofloxacin shows 12.5% resistance to Salmonella.This may be due to indiscriminate use of drugs.Moderate costs, advantage of oral route, tolerability, convenient dosage schedule has contributed towards its indiscriminate use.To conclude, emergence of resistance to antibiotics is clearly accelerated.Multidrug resistance increases burden on economy and health costs, the patient is more likely to require prolonged hospitalization and treatment with more expensive and more toxic drugs with consequent risk of treatment failure and death.Salmonellae are no longer to be considered as to have predictable antibiotic sensitivity.Appropriate antibiotic indicated by sensitivity tests should be employed to prevent the development of resistant strains of Salmonella.Conflict of interest-None to declare