Padmaja and Rao: Bacteriological profile and antibiogram of bronchoalveolar lavage fluid from patients with respiratory tract infections at a tertiary care Hospital


Introduction

Pulmonary infections are the most common Infectious disease of humans worldwide.1 Pulmonary infections present with cough with expectoration, dyspnoea, wheeze, chest pain/ discomfort, to life-threatening infections for 1-3 weeks.2 These infections pose a permanent & pervasive health problem that compose an enormous burden on society and are with reasons for consultation & hospitalization. These infections range from self-limiting illnesses to potentially life-threatening infections.3

Respiratory tract infections (RTI) are among the leading causes of morbidity & mortality in the world. RTI is a term assigned not to a single disease but a spectrum of infections, each with different epidemiology, clinical presentation, pathology & prognosis. The etiology, signs & symptoms of respiratory diseases vary with age, sex, seasons, type of population at risk, and various other factors. The lower respiratory tract infections are responsible for 6% among all patients with infectious diseases attending out-patient departments in tertiary care hospitals and 4.4% hospital admissions.4

Of these, chronic respiratory diseases account for 4 million deaths annually, contributing to 5% of global deaths.1 Exacerbations punctuate the course of the disease. Respiratory tract infections are the most frequent causes of exacerbations associated with greater & irreversible decline in lung function, significant mortality & morbidity.4 Early diagnosis and proper choice of antimicrobials are crucial for the management of these patients.5 The bacteriological profile of respiratory tract infections varies within the same country due to differences in the frequency of antibiotics, environmental factors, and ventilation in critically ill patients.

Since the etiological profile of respiratory infections cannot be determined clinically, the microbial investigation is required for both treatment and management of these cases.

Bronchoalveolar lavage [BAL] fluid is an ideal sample used for the recovery of these pathogens. BAL is increasingly utilized as a diagnostic tool, though it remained an investigative and research tool in the past. The advent of bronchoscopy and quantitative analysis of BAL have improved sensitivity and specificity in diagnosing pulmonary infections.

Hence, this study was performed to detect pathogenic organisms by microscopy of BAL fluid and isolate and identify various bacteria and fungi from BAL fluid in culture and analyze their antibiogram.

Materials and Methods

This retrospective study was conducted in the Department of Microbiology, KIMS&RF, Amalapuram, from July 2018 to October 2019. BAL fluid specimens were collected under aseptic precautions and transported to the laboratory immediately for processing. A total of 135 BAL fluid samples were included in the study. These samples were carefully observed for consistency, colour, and odour. The initial microscopic examination consisted of Gram stain and wet mount preparation, which were observed for pus cells, epithelial cells, bacteria, and yeast cells.

Later, they were inoculated on Mac Conkey Agar, Blood agar, and Chocolate agar using a sterile 4mm nichrome loop and incubated at 37o c for 24-48 hours using standard laboratory techniques. The Petri dishes were observed the next day for any bacterial growth and were identified by their morphological, cultural, and biochemical characteristics. For fungal growth, the sample was inoculated on Saborauds dextrose agar [SDA] and incubated at 37oc for seven days, and observed for growth.

The antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method for bacterial isolates as per Clinical and Laboratory Standards Institute guideline [CLSI]-2014. Zone diameter was measured in millimetres and interpreted as per CLSI guidelines.5

Inclusion criteria

Patients between 20-70 years presenting with symptoms like fever with purulent sputum, breathing difficulty with physical findings suggestive of consolidation.

Exclusion criteria

Patients with cardiac diseases, and pregnant women.

Results

Out of the total 135 samples, 78 (58%) were from males, and 57 (42%) were female patients. The majority of cases were in the age group 51-60years, followed by the age group 61-70 yrs. The least number of patients belonged to the age group between 18-30yrs.

Table 1

Age and sex distribution of subjects

S.No

Age group

Male

Female

Total

1

18-30

07

05

12

2

31-40

01

16

17

3

41-50

15

06

21

4

51-60

37

14

51

5

61-70

18

16

34

Total

78

57

135

Out of 135 samples processed, 52 (58%) were positive for growth on culture. Most of the isolates were Gram-negative bacteria(GNB). Among 52 isolates, 49 were GNB, and 3 were fungal isolates. The predominant GNB was Klebsiella pneumoniae 30(61%), followed by Pseudomonas aeruginosa 15(30%), Esch. coli 4(8%) and the fungal isolate was Aspergillus niger 3(1%).

Table 2

Spectrum of bacterial isolates from BAL fluid

S.No

Isolates

No. of isolates

Percentage %

1

Klebsiella

30

61

2

Pseudomonas

15

30

3

Esch.coli

04

08

4

Aspergillus niger

03

01

Total

52

Table 3

Occurrence of isolates in different age groups

S.No

Isolate

18-30 n =12

31-40 n =17

41-50 n =21

51-60 n =51

61-70 n =34

Total

1

Klebsiella

3(25%)

3(17.4%)

6(12%)

11(21%)

7(11%)

30

2

Peudomonas

2(16.66%)

2(11.74%)

2(9.52%)

6(11.76%)

3(8.82%)

15

3

Esch.coli

1(6.33)

0

0

2(3.92%)

1(2.94%)

04

4

Aspergillus niger

0

0

0

2(3.92%)

1(2.94%)

03

The highest numbers of isolates were in the age group of 51-60yrs followed by 61-70yrs, and the least number of isolates was in the age group of 18-30yrs.

Antibiotic sensitivity patterns observed

Klebsiella & Pseudomonas were highly sensitive to amikacin, piperacillin-tazobactam, imipenem, gentamycin, followed by tobramycin. They showed resistance to cephalosporins and slightly resistant to ciprofloxacin also.

Table 4

Resistant pattern of gram-negative isolates

Antibiotic

Klebsiella (30)

Pseudomonas (15)

E.coli (4)

Amikacin

4(13%)

3(20%)

1(25%)

Piperacillintazobactm

6(20%)

4(27%)

-

Gentamycin

6(20%)

4(27%)

-

Tobramycin

6(20%)

4(27%)

-

Cephalexin

25(83%)

10(67%)

3(75%)

Cefuroxime

24(80%)

12(80%)

2(50%)

Ceftriaxone

24(80%)

12(80%)

2(50%)

Cefepime

26(87%)

12(80%)

1(25%)

Ciprofloxacin

20(67%)

9(60%)

1(25%)

Tetracycline

16(53%)

10(67%)

2(50%)

Imipenem

6(20%)

3(20%)

-

Discussion

Chronic respiratory diseases represent a public health challenge in industrialized and developing countries because of their frequency and socioeconomic impact. They are the second most common cause of hospital-acquired infections with increased mortality and morbidity across the globe. Pneumonia is a frequent complication in patients with severe respiratory infections.

The present study was conducted to determine the bacterial etiology in patients with respiratory infections with the perspective of evaluating BAL fluid, which provides a handy diagnostic tool. The quality of BAL fluid was assessed based on gram stain findings followed by culture and sensitivity testing. The present study showed positive BAL cultures in 52 samples out of 135 samples collected. Of these, GNB were the predominant organisms, being 49 and 3 were fungal growths. These results are similar to the studies done by Goel et al.6 Barsanth et al.7 The maximum number of positive cases were between the age group 51-60yrs followed by 61-70yrs. This may be due to more respiratory cases observed with increasing age which lowers host defense.8 The rate of isolation was higher in males(58%) than in females(42%) shown in Table 1, which was on par with the findings of Shah et al.,9 Birasen Behera et al.10

In this study, among culture-positive GNB cases, Klebsiella pneumoniae was the commonest bacterial isolate followed by Pseudomonas and E. coli which is correlating with studies of Madhavi et al.,11 Ratna S et al.,12 Veena et al. and Viswanath et al.13

In our study, all GNB isolates were susceptible to amikacin followed by piperacillin-tazobactam, gentamycin, tobramycin, and imipenem while resistant to cephalosporins. Similar findings were observed by Regha IR et al.14 Goel et al.,6 Barsanti et al.7 Olugbue V. Onouha et al.15 This resistance to cephalosporins may be due to incomplete treatment. Also, in our study Klebsiella and Pseudomonas were resistant to ciprofloxacin which is in concordance with Regha IR et al.14

In our study, most gram-negative isolates were sensitive to amikacin, piperacillin, tazobactam, followed by imipenem. Therefore it can be one of the best combinations for treating infections induced by gram-negative bacilli, which are similar to the study reported by Olugbue V. Onouha Set al.15

Conclusion

The study's main objective was to identify the microbiological profile of BAL fluid isolated from pulmonary infections. Results of the present study demonstrate the high incidence of gram-negative isolates. The study also suggests that regular antimicrobial sensitivity monitoring should be done as most isolates are highly resistant to cephalosporin and other commonly used antimicrobials.

Source of Funding

None.

Conflict of Interest

The authors declare that there is no conflict of interest.

References

1 

SK Mishra HP Kattel J Acharya NP Shah AS Shah JB Sherchand BM Pokhrel Recent trend of bacterial aetiology of lower respiratory tract infection in a tertiary care centre of NepalInt J Infect Microbiol2012113810.3126/ijim.v1i1.6639

2 

S Panda NB Prema TV Ramani Lower respiratory tract infection -Bacteriological profile and antibiogram patternInt J Cur Res Rev201242114955

3 

AO Okesola OM Ige Trends in Bacterial Pathogens of Lower Respiratory Tract InfectionsIndian J Chest Dis Allied Sci20085026972

4 

GU Meduri DH Beals AG Maijub V Baselski Protected Bronchoalveolar Lavage: A New Bronchoscopic Technique to Retrieve Uncontaminated Distal Airway SecretionsAm Rev Respir Dis19911434_pt_18556410.1164/ajrccm/143.4_pt_1.855

5 

National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial susceptibility testing. Clinical and Laboratory Standards Institute2014

6 

K Bala U Chaudhary N Goel R Aggarwal Antibiotic sensitivity pattern of gram negative bacilli isolated from the lower respiratory tract of ventilated patients in the intensive care unitIndian J Crit Care Med20091331485110.4103/0972-5229.58540

7 

MC Barsanti KF Woeltje Infection Prevention in the Intensive Care UnitInfect Dis Clin N Am20092337032510.1016/j.idc.2009.04.012

8 

M Merino-Sánchez I Alfageme-Michavila NR Núñez J Lima-Alvarez Prognosis in patients with pneumonia and chronic obstructive pulmonary diseaseArch Bronconeumol2005411160711

9 

MA Naik GN Dhobi BA Shah G Singh Bacteriological and clinical profile of Community acquired pneumonia in hospitalized patientsLung India201027545510.4103/0970-2113.63606

10 

B Behera KK Sahu P Bhoi Jatindra Nath Mohanty. Prevalence and antimicrobial susceptibility patterns of bacteria in ICU patients with lower respiratory tract infection: A cross-sectional studyJ Acute Dis20209415760

11 

S Madhavi MV Ramarao R Janardhanrao Bacterialetiology of acute exacerbations of chronic obstructive pulmonary diseaseJ Microbiol Biotech Res2012234404

12 

S Ratna Bacteriological Profile and Antibiotic Susceptibility Pattern of Lower Respiratory Tract Infectionin A Tertiary Hospital In North-East IndiaInt J Recent Sci Res2017892033740

13 

S Viswanath K Chawla A Gopinathan Multidrug-resistant Gram-negative bacilli in lower respiratory tractinfectionsIran J Microbiol2013543237

14 

IR Regha B Sulekha Bacteriological profile and antibiotic susceptibility patterns of lower respiratory tract infections in a tertiary care hospital, Central KeralaInt J Med Microbiol Trop Dis20184418690

15 

V Olugbue S Onuoha Prevalence and antibiotic sensitivity of bacterial agents involved in lower respiratory tract infectionsInt J Biol Chem Sci20115210.4314/ijbcs.v5i2.72151



jats-html.xsl

© This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


  • Article highlights
  • Article tables
  • Article images

Article History

Received : 08-07-2021

Accepted : 16-07-2021

Available online : 31-07-2021


View Article

PDF File   Full Text Article


Copyright permission

Get article permission for commercial use

Downlaod

PDF File   XML File   ePub File


Digital Object Identifier (DOI)

Article DOI

https://doi.org/10.18231/j.ijmr.2021.023


Article Metrics






Article Access statistics

Viewed: 234

PDF Downloaded: 103



Wiki in hindi