Prevalence and resistance pattern of Moraxella catarrhalis in community-acquired lower respiratory tract infections

Abstract

Introduction

Moraxella catarrhalis previously considered as commensal of upper respiratory tract has gained importance as a pathogen responsible for respiratory tract infections. Its beta-lactamase-producing ability draws even more attention toward its varying patterns of resistance.

Methods

This was an observational study conducted to evaluate the prevalence and resistance pattern of M. catarrhalis. Patients aged 20–80 years admitted in the Department of Chest Medicine of Liaquat National Hospital from March 2012 to December 2012 were included in the study. Respiratory samples of sputum, tracheal secretions, and bronchoalveolar lavage were included, and their cultures were followed.

Results

Out of 110 respiratory samples, 22 showed positive cultures for M. catarrhalis in which 14 were males and eight were females. Ten samples out of 22 showed resistance to clarithromycin, and 13 samples out of 22 displayed resistance to erythromycin, whereas 13 showed resistance to levofloxacin. Hence, 45% of the cultures showed resistance to macrolides so far and 59% showed resistance to quinolones.

Conclusion

Our study shows that in our environment, M. catarrhalis may be resistant to macrolides and quinolones; hence, these should not be recommended as an alternative treatment in community-acquired lower respiratory tract infections caused by M. catarrhalis. However, a study of larger sample size should be conducted to determine if the recommendations are required to be changed.

Keywords:

• community-acquired lower respiratory tract infections or pneumonia
• M. catarrhalis
• antibiotic resistance
• gram-negative diplococcic
• Pakistan

Acknowledgments

Dr Safia Bader Uddin Shaikh would like to make the following statement: I am grateful to my parents and siblings who have always been there encouraging me through my toughest moments.

I would like to express my deepest appreciation to all those who provided me with their help and support to complete my research, especially my supervisor Dr Zafar Ahmed and my HOD (head of the department) Dr Syed Ali Arsalan. Also I thank Dr Aneel Chauhan for his guidance, and last but not the least, Mr Waqar Ahmed who would always make time in his busiest schedule. I would also like to thank the HOD of microbiology department Dr Saba Qaiser for letting me review the records.

Disclosure

The authors report no conflicts of interest in this work.