Antimicrobial Profile and Prevalence of Salmonella Species from Blood Culture in A Tertiary Care Hospital

Introduction: Enteric fever is a major public health concern around the world and endemic in low-and middle-income countries like, India. Typically, it spreads through contaminated food or water. Salmonella Typhi proliferate and spread throughout the bloodstream seeding multiple organs in the body. Incidence data of culture confirmed Typhoid cases is approximately 377per 100000 population with an approximate case fatality rate of 1% in India. The management of cases are hampered due to emerging the drug resistance of isolates because of rampant and misuse of antibiotics. This study investigates to analyse the current pattern of antibiotic susceptibility among Salmonella isolates from cases of enteric fever seen at ESIC Medical


Introduction
Enteric fever is a major public health concern around the world and endemic in low-and middle-income countries like, India.Typhoid fever and Paratyphoid fever, which are both life-threatening illnesses, are caused by Salmonella Typhi and Salmonella Paratyphi A, respectively. 1,2Typically, it spreads through contaminated food or water.Salmonella Typhi proliferate and spread throughout the bloodstream seeding multiple organs in the body. 1 The disease's signs and symptoms are likely to appear gradually, one to three weeks after contact.
Incidence data of culture confirmed Typhoid cases is approximately 377 per 100000 population with an approximate case fatality rate of 1% in India. 3Early disease management can be aided by quick diagnosis, and precise antibiotic sensitivity testing guiding the treatment protocol. 4Empirical therapy is usually followed when laboratory confirmation is not done in many outpatients setup.Typhoid fever morbidity and mortality have decreased dramatically in industrialised countries as a result of improved housing conditions and the use of drugs. 1 The management of cases are hampered due to emerging the drug resistance of isolates because of rampant and misuse of antibiotics.
Chloramphenicol, ampicillin, and cotrimoxazole are no longer frequently used to treat typhoid fever in endemic areas, and quinolones have taken their place as the drug of choice.This is because Multi-Drug Resistant (MDR) strains have emerged.

Results
During the study period, a total of 4064 blood culture specimens were received from the patients suspected for fever, out of which 66.85% (2717/4064) showed blood culture positive and remaining 33.14% (1347/4064) samples were showed no growth on blood culture media.

Discussion
Enteric fever is the most common cause of pyrexia of unknown origin.Limited laboratory diagnosis is the reason for under estimation of the true incidence of the disease in India.Data on culture positive typhoid cases is required to estimate the prevalence of the disease, its aetiology and antimicrobial susceptibilities. 9Such data is must to formulate & focus policy decisions for control, preventing and managing the diseases.Over the counter use of antibiotics is also impact the AST data of the isolates in question.The study generated data by examining data of 373 Salmonella isolates over a period of 3 years.Among the positive blood cultures,
The traditional 1 st line agents (Ampicillin, Chloramphenicol, Cotrimoxazole), were found to have a better susceptibility profile.The current data shows a good response to the 1 st line agent.This observation is also reported by studies done in India by Veeraraghavan B, Pragasam AK et al 10 and neighbouring countries i.e., Nepal. 11,12e postulated hypothesis for the recovery to the drug effect can be because of decrease clinical use of these agents for years, thus decreasing the selection pressure on bacteria.Such data strengthens the concept and importance of Antimicrobial Stewardship.
Among the 2 nd line agents, ceftriaxone was universally susceptible in all isolates whereas, Azithromycin showed moderate level resistance.
These agents are currently used for empirical therapy by most clinicians in India for typhoid cases.The data in our study corroborates with data projected from North India showing emergence of resistance towards Azithromycin among Salmonella isolates.In contrast, South Indian states have observed higher MIC of isolates towards ceftriaxone.The reason has been attributed to the prescribing practices in these areas. 13lidixic acid resistance has been used as indirect evidence of increased Minimum Inhibitory
Similar to study in Central India showing 96% NARST isolates.These are higher in comparison to other Indian studies, which reports isolates in the range of 60-78%. 15,16,17

Conclusion
Treatment with appropriate antimicrobial drugs is crucial for patients with typhoidal infections and the antimicrobial susceptibility of such isolates must be reported as soon as possible.The changing trends to resistance to 1 st and 2 nd line drug can help formulate empirical therapy plans as per the epidemiologic profile of any given geographic area.Antibiotic Stewardship steps like rotation of drugs can be evidently useful to manage these cases.Evidence of antimicrobial resistance supports the need for continuous surveillance.Antibiotic resistance is here to stay, and our communities can only be saved by wise planning and an appropriate antibiotic policy.

Table 2 showed
AST data of the Salmonella isolates.

Table 1
Distribution of total number of isolates on the basis of gram staining

Table 2
Antimicrobial susceptibilities of Salmonella enterica.

Table 3
Distribution of nalidixic acid (NA) resistant S. Typhi and S. Paratyphi.