Original article / research
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Prevalence and Antimicrobial Susceptibility Pattern of Bacterial Agents Involved in Lower Respiratory Tract Infection at a Tertiary Care Hospital, Jaipur, Rajasthan, India |
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Ashina Singla, Nitin Kumar, Preeti Chaudhary, Ved Prakash Mamoria 1. Associate Professor, Department of Microbiology, Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan, India. 2. Postgraduate Student, Department of Microbiology, Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan, India. 3. Resident, Department of Microbiology, Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan, India. 4. Professor and Head, Department of Microbiology, Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan, India. |
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Correspondence
Address : Dr. Ashina Singla, Associate Professor, Department of Microbiology, MGUMST, Jaipur, Rajasthan, India. E-mail: aashina14@gmail.com |
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ABSTRACT | |||||||||||||||||||||||||||||||||||||||||||||||||||||
: Lower Respiratory Tract Infection (LRTI) is one of the commonest health problems which is not a single disease but a group of specific infections with varying aetiology and symptomatology. These infections are the leading cause of illness and mortality in children and adults across the world because of different epidemiology, pathogenesis, clinical presentation, and outcomes. Aim: To find out the prevalence, bacteriological profile and antimicrobial susceptibility pattern of clinical isolates causing LRTI. Materials and Methods: This was a laboratory based observational study which was carried out between June 2019 to May 2020. All the lower respiratory tract samples (sputum, Endotracheal (ET) aspirate, Bronchoalveolar Lavage (BAL) etc.,) were collected and sample processing was done for isolation and identification by standard methods and antimicrobial susceptibility testing was done using Kirby Bauer disc diffusion method. The data was analysed in Microsoft Office excel worksheet. Results: A total number of 1364 samples were processed in which 615 were culture positive. ET aspirates 65.04% (n=400) showed higher positivity rate than sputum 32.03% (n=197). In this study, gram positive and gram negative bacteria (GNB) were 4.23% (n=26) and 92.19% (n=567) respectively with yeast recovered in only 3.58% (n=22) of the specimens. Among the isolates, Klebsiella pneumoniae 171 (30.15%) was the most common organism. The overall susceptibility of GNB was highest towards tigecycline (51.85%) followed by gentamicin (38.62%). Conclusion: Specific antibiotic utilisation strategies like antibiotic restriction, combination therapy may help to decrease or prevent the emergence of resistance. There is a need for further community based studies to identify the best treatment protocol for individual patients. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Keywords : Endotracheal aspirate, Klebsiella pneumoniae, Sputum culture | |||||||||||||||||||||||||||||||||||||||||||||||||||||
INTRODUCTION | |||||||||||||||||||||||||||||||||||||||||||||||||||||
The LRTIs are amongst the most common infectious diseases of humans worldwide (1). These are the leading cause of illness and death in children and adults across the world. LRTIs are any infection in the lungs, trachea, bronchi, bronchioles, alveoli, or below the larynx. LRTI’s is not only one disease, but a cluster of specific infections each with different epidemiology, pathogenesis, clinical presentation, and outcome. The symptoms and aetiology of respiratory diseases vary with age, gender and the type of population at risk. LRTI’s may be defined as those infections presenting with symptoms including cough, expectoration, dyspnea, wheeze, and/or chest pain/discomfort usually for a period ranging from 1-3 weeks. Acute manifestations of LRTIs that may or may not involve lungs include acute bronchitis, bronchiolitis, influenza, community-acquired pneumonia either with or without radiological evidence, acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD), and acute exacerbation of bronchiectasis (2). A 4.4% of all hospital admissions and 6% of all general practitioner consultations are due to infections of the lower respiratory tract (3). Hospital-acquired and community-acquired LRTI’s have been on the rise as seen with other immunocompromised conditions which include asthma, COPD, diabetes, chronic kidney disease (4),(5),(6). Respiratory infection accounts for a major health burden causing about 50 million deaths per year (7). It has been seen that 13.3% of Disability–Adjusted Life Years (DALYs) are due to respiratory diseases (8). As reported by the World Health Organisation (WHO), among the infectious disease deaths in India LRTI’s have been attributed to account for almost 20% mortality (9). They account for 3-5% of deaths in adults (10). The problem is much greater in developing countries where pneumonia is the most common cause of hospital attendance in adults (11). In developing countries, the situation is more complicated and management is often difficult due to the problem associated with the identification of the aetiological agents and administration of appropriate treatment in cases requiring antibiotic therapy (12). Since the aetiological agents of LRTI cannot be determined clinically, microbiological investigation is required for both treatment and management of the individual case and epidemiological purposes (13),(14). This study aims to determine the prevalence and antimicrobial susceptibility pattern of bacterial agents causing LRTI at a tertiary care hospital of Jaipur, Rajasthan, India. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
MATERIAL AND METHODS | |||||||||||||||||||||||||||||||||||||||||||||||||||||
This was a laboratory based observational study which was carried out between June 2019 to May 2020 at Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan, India, after getting the Institutional Ethical Committee (IEC) approval (MGMCH/IEC/JPR/2019/16) and informed consent. A total of 1364 respiratory specimens were received during the study period. Inclusion criteria: Lower respiratory tract sample were included in the study. Exclusion criteria: Sample other than lower respiratory tract sample were excluded from the study. Study Procedure All the lower respiratory tract samples (sputum, ET aspirate, BAL etc.,) of patients coming to the outpatient and in-patient department of MGMCH with symptoms of LRTI were collected for bacteriological culture into a wide-mouthed sterile containers, transported to the laboratory and processed within two hours. Gram’s staining was done for all the received samples and then inoculated onto Blood agar, Chocolate agar and MacConkey agar. Streaked culture plates were incubated at 37°C overnight. On the next day, the bacterial growth was observed, and was further processed for identification. Bacterial isolates were identified on the basis of colony characteristics, gram-staining, and a battery of biochemical tests. The antimicrobial susceptibility test was done by Kirby Bauer disc diffusion method. Interpretation of antimicrobial susceptibility was done by Clinical and Laboratory Standards Institute (CLSI) guidelines (15). STATISTICAL ANALYSIS The data was entered in Microsoft office excel worksheet. The data was analysed as number and percentage. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
RESULTS | |||||||||||||||||||||||||||||||||||||||||||||||||||||
A total of 1364 respiratory specimens were received during the study period. Out of which 615 (45.08%) were culture positive. ET aspirates showed higher positivity 65.04% (n=400/615) followed by sputum 32.03% (n=197/615) and BAL 2.93% (n=18/615). Most of the culture positive samples were received from the IPD 97.24 (n=598) and 2.76% (n=17) were from OPD. Patients enrolled in the study included male 81.14% (n=499) as compared to female 18.86% (n=116). Most of the culture positive isolates were from patients in the age group of 61-70 years (n=137, 22.27%) (Table/Fig 1). Out of the 615 positive cultures, bacterial isolates were recovered from 96.42% (n=593) and fungal isolates from 3.58% (n=22) cultures. Out of the bacterial isolates, gram positive and gram negative bacteria were 4.23% (n=26) and 92.19% (n=567), respectively with yeast isolates recovered in only 3.58% (n=22) of the specimens. Among the gram negative isolates, Klebsiella pneumoniae 30.15% (n=171) was the most common organism isolated, followed by Acinetobacter baumanii 28.21% (n=160), Pseudomonas aeruginosa 19.40% (n=110), Escherichia coli 15.16% (n=86) (Table/Fig 2). Among the gram positive bacteria, Staphylococcus aureus was the most predominant spp. isolated 50% (n=13) followed by Staphylococcus haemolyticus 26.92% (n=07) (Table/Fig 3). The antimicrobial susceptibility pattern of the isolated bacteria is as follows: Gram negative bacteria showed highest sensitivity against Tigecycline (51.85%) and Gentamicin (38.62%) (Table/Fig 4). In Gram positive bacteria Linezolid (88.5%) and Tigecycline (84.6%) showed high sensitivity (Table/Fig 5). | |||||||||||||||||||||||||||||||||||||||||||||||||||||
DISCUSSION | |||||||||||||||||||||||||||||||||||||||||||||||||||||
In this study, LRTI cases are more common in male (81.14%) as compared to female (18.86%) which were similar to other studies done by Panda S et al., and Akingbade OA et al., (16),(17). Maximum cases of LRTI in this study has been encountered in the age group of 61-70 years (n=137/615) and minimum cases were found in 91-100 years (n=2/615). The findings are supported by studies done by Ahmed SM et al., (18). In this study, overall culture confirmed cases were found to be 45.08% (n=615) of which ET aspirates 65.04% (n=400) showed higher positivity rate than sputum 32.03% (n=197). Study done by Mishra S et al., also showed greater positivity in ET aspirates than sputum samples (19). This study shows isolation of gram positive organisms 4.23% (n=26) and gram negative 92.19% (n=567). Similar observations have been shown in other studies as Saha A, in (Tripura) (20). Here, the most common organisms isolated were Klebsiella pneumoniae (30.15%) followed by Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli. These findings were similar to other studies done by Tripathi Purti C and Kiran D showing Klebsiella pneumoniae as the major isolate causing LRTI (21). In this study, gram negative bacteria showed high sensitivity against tigecycline (50.85%) and gentamicin (38.62%) which finds similarity to other studies done by Verma S, who also reported that tigecycline was highly sensitive in gram negative isolates (22). Among gram-positive isolates, most commonly isolated bacteria were Staphylococcus aureus (50%) followed by Staphylococcus haemolyticus (26.92), Enterococcus faecium (19.23), Enterococcus faecalis 3.85% (n=1). In gram positive bacteria linezolid (100%) and tigecycline (100%) showed highest sensitivity. Present study was similar to other studies; Singh S et al., who also reported that linezolid is the most sensitive drug found in gram positive isolates (23). Gram positive bacteria in this study also showed sensitivity to Vancomycin (76.92%), Tetracycline (57.7%) similar to study done by Regha IR and Sulekha B, (24). The antimicrobial susceptibility pattern suggests that aminoglycosides like gentamicin can be a good choice as similar to study done by Ahmed SM et al., (18). The study revealed that the changing antibiotic susceptibility patterns of bacterial pathogens are of great concern which leads to the emergence of resistant strains. The injudicious use of antibiotics is also considered as a direct cause of antibiotic resistance worldwide (25). Hence, studies targeting formulation of local antibiogram of lower respiratory tract pathogens should be carried out at every centre which may guide the treating physicians to start empirical therapy. Specific antibiotic utilisation strategies like antibiotic restriction, combination therapy may also help to decrease or prevent the emergence of resistance. Limitation(s) Atypical pathogens like Mycoplasma pneumoniae, Chlamydia trachomatis etc., and viruses have not been reported in this study. For the detection of these atypical pathogens, advanced techniques like molecular assays are required which were not done in this study. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
CONCLUSION | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Present study revealed the changing antibiotic susceptibility patterns of bacterial pathogens. The antimicrobial therapy should be based on the intensive diagnostic work up along with patients’ risk factors so that it provides the clinician appropriate information required for choosing right antibiotics. Frequent campaigns should be carried out to create awareness about judicious use of antibiotics to reduce the emergence of antimicrobial drug resistant organisms. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
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