Antibiotic susceptibility of bacterial strains and bacteriological proﬁle from patients with lower respiratory tract infections in a teaching hospital

Background: Lower respiratory tract infections (LRTI) are one of the commonest health problems demanding frequent consultation and hospitalization. Unnecessary and inappropriate initial antibiotic therapy is a potentially modiﬁable factor that is associated with increased mortality in patients with serious infections. Aim of the study: To study bacterial proﬁle and susceptibility pattern of lower respiratory tract infections in a teaching hospital. Materials and Methods: Prospective study done in the department of Microbiology at Prathima Institute of Medical Sciences, Nagunuru, Karimnagar, Telangana., Tover a period of 18 months ie from January 2019 to July 2020. A total of 120 samples from respiratory tract were studied for bacterial isolates and antibiotic susceptibility. Results: A total of 120 cases were studied. The male to female ratio was 2:1. Among the bacterial isolates, 76.6% were Gram negative bacilli and 23.3% were gram positive cocci. Among Gram negative bacteria, the predominant bacterial isolate was Klebisella. pneumoniae (45.8%) followed by Pseudomonas. aeruginosa (28.3%.) Conclusion: Present study, was based on the pattern of resistance to commonly used antibiotics by organisms causing lower respiratory tract infections (LRTIs) in our institute. This may help us to study the more susceptible group of drugs in our institute which would help prepare an antibiogram and develop a policy for rational antibiotic prescription.


Introduction
Lower respiratory tract infections (LRTIs) are one of the serious communicable diseases and the 3rd leading cause of death globally, after ischaemic heart and cerebrovascular diseases. 1 In developing countries management of LRTIs is difficult in both children 2 and adults, 3 especially due to the issues associated with identification of the etiological agents and selection of appropriate antibiotics. LRTIs in adults include lower respiratory tract infections, acute bronchitis, influenza,

Aim of the study
To study the bacteriological profile and susceptibility pattern of lower respiratory tract infections in a teaching hospital in karimnagar, Telangana

Materials and Methods
The study was approved by the Institutional Ethics Committee.
Written informed consent was obtained from all the cases included in the study.
A written informed consent was obtained from all the participants included in the study.
There were no ethical issues involved Prospective study done in in the department of Microbiology at Prathima Institute of Medical Sciences, Nagunuru, Karimnagar, Telangana. Over a period of 18 months from January 2019 to July 2020. There were a total of 220 cases of suspected LRTI of which 120 were studied.

Methodology
The patients with lower respiratory tract infections visiting the department of Pulmonology were selected based upon the above criteria. A proper detailed clinical history was taken. All the relevant investigations were done including routine investigations such as hemogram, complete urine examination, and relevant biochemical investigations. Findings were recorded in a predesigned proforma. The procedure for collection of sputum samples was instructed to the patients in the department of microbiology. The sputum samples were collected into well labelled sterile, wide mouthed glass bottles with screw cap tops. Tracheal and bronchial alveolar fluid samples were sent from the department of pulmonology immediately without any delay, to the microbiology laboratory.
Bacterial culture and antimicrobial susceptibility testing were done.
The sputum samples were inoculated onto Blood agar plates, Chocolate agar plates and MacConkey agar plates.
Blood agar plates and MacConkey agar plates were incubated aerobically at 37-degree Celsius for 24 hours.
The inoculums on the plate were streaked with a sterile wire loop and observed for growth of colonies while Chocolate agar plates were incubated in an atmosphere containing extra carbon dioxide in candle jar.
All the bacteria were isolated and identified using morphology, microscopy.

Observations and Results
A total of 220 samples were collected and screened, of which 120 were pathogenic.
Data was made for these120 cases. In the present study age distribution ranged from 5 years to 75 years.
Most common age group affected was between 46-55 years, followed by 22.5% among 56 -65 years.

Comparative studies related to age distribution
In the present study, age distribution varied from 5 to 75 years. Most common age group was between 46-55 years with a mean age of 48 years, followed by 22.5% among 56-65 years. This was compared with other studies. In the study by Tchatchouang S et al 9 the patient age ranged from 18 to 94 years with a median age of 50 years. In the study by Nurahmed N et al 10 the mean age of was 38±14 years, and the highest proportion of participants was in the age range of 18-27 years (31.1%), followed by the age range 28-37 years (22.1%).

Comparative studies related to gender distribution
In the present study, males were predominant when compared to females and the male: female ratio was 2:1. Similar findings were observed by Tchatchouang S et al 9 where they also observed the male predominance and male/female sex ratio of 1.8. Nurahmed N et al 10 noted slight female predominance in their study with 112 males and 128 females.

Comparative studies related to site of swabs
In the present study, among 120 samples collected, sputum swabs constituted 45%, pleural fluid 8.3%, tracheal aspirates 25%, bronchoalveolar fluid 16.6%, and endotracheal tube secretions were 5%. In a study done

Comparative studies related to antimicrobial sensitivity
In the present study, K. pneumonia was the most common prevalent bacteria with a susceptibility pneumoniae was the most prevalent bacteria with a susceptibility of 98% to Amikacin. The susceptibility profile of S. aureus was 97% to Amikacin.K. pneumoniae was the second most prevalent bacteria with a susceptibility of 95% to Amikacin. P. aeruginosa had a susceptibility profile of 87% to Amikacin.

Conclusion
Present study, was based on the pattern of resistance to commonly used antibiotics by organisms causing lower respiratory tract infections (LRTIs) in our Institute. This may help us to study the more susceptible group of drugs in our institute which would help to prepare an appropriate antibiogram for rational antibiotic prescription.

Limitations
The present study has a number of limitations, and to appreciate the findings, some issues need to be addressed as Small sample size of the study. A distinction between community-acquired and hospital-acquired infections could not be made. Resultant morbidity and mortality was not analysed in study.