Mycological Findings of Sputum Samples from Pulmonary Tuberculosis Patients Attending TB Clinic in Nairobi, Kenya

Elizabeth Nyambura Mwaura Vivian Matiru

doi:10.4172/2161-0517.1000119

Abstract

Objective: To determine the prevalence of fungal pathogens in patients with pulmonary tuberculosis at Mbagathi District Hospital TB clinic. Design: One hundred and seventy two sputum samples were collected from patients who were confirmed to have pulmonary tuberculosis at Mbagathi District Hospital TB clinic. These samples were subjected to mycological investigation using microscopy and culture. Results: Pulmonary fungal pathogens were isolated as co-pathogens with Mycobacterium tuberculosis in 76 (44.18%). Yeasts accounted for 46/172 (26.7%), with 33/172 (19%) being Candida albicans, 3/172 (1.7%) were identified as Candida dubliniensis, 1/172 (0.6%) was Candida guilliermondii, while 3/172(1.7%) were Candida tropicalis. Cryptococcus laurentii was isolated in 2/172 (1.2%). Colonization of Mycobacterium tuberculosis with moulds was as follows: 2/172 (1.2%) Aspergillus flavus, 3/172 (1.7%) Aspergillus fumigatus 4/172 (2.3%) Aspergillus niger, 2/172 (1.2%) Scytalidium hyalinum and 4/172 (2.3%) Trichosporon asahii. Pneumocystis jirovencii oocysts were positive in 19/172 (11.0%) on Toluidine O blue. Gram stain of the sputum samples yielded: 4/172 (2.3%) Gram negative rods, 10/172 (5.8%) Gram positive cocci and 6/172(3.5%) Gram positive rods. Conclusion: Pathogenic fungi and other bacterial pathogens may be significant co-infecting pathogens complicating the management of TB. Clinicians in Kenya should be aware of co-infection of Mycobacterium tuberculosis with opportunistic pulmonary fungal and bacterial pathogens. HIV infection is a significant pre-disposition to pulmonary tuberculosis. The two conditions present severe immunosuppression. Confounded by prolonged TB treatment, this group represents a high risk for acquiring opportunistic fungal pathogens.

Highlights

The incidence of fungal pneumonias has increased significantly since the 1960s, due to increasing number of immunocompromised patients [1,2]
One (0.6%) was positive for yeast cells together with fungal elements, and 3/172(1.7%) of the samples were positive for Gram negative rods and 10/172 (5.8%) were positive for gram positive cocci, 8/172(4.7%) were Gram positive rods, while 85/172 49.4% of samples were scored negative for potential pathogens on Gram reaction (Table 1)
Yeasts were isolated in 46/172 (26.7%) samples, in which 33/172 (19.2%) were Candida albicans, 3/172 (1.7%) were Candida dubliensis, 1/172 (0.6%) was Candida guilliermondii, 3/172 (1.7%) were Candida tropicalis

Summary

Introduction

The incidence of fungal pneumonias has increased significantly since the 1960s, due to increasing number of immunocompromised patients [1,2]. The opportunistic fungi, which are either ubiquitous or part of normal flora and infections, are acquired by inhalation of contaminated soil [3]. Cryptococcus neoformans can infect people with intact immune systems at a rate of 0.2 cases per million populations per year. Cryptococcosis is caused by members of the Cryptococcus neoformans species complex, comprising the three variants C. neoformans v. Cryptococcosis is believed to be acquired by inhalation of the infectious propagule from the environment. The prevalence of cryptococcosis has been increasing over the past 20 years for many reasons, including the HIV pandemic and the expanded use of immunosuppressive drugs [6]. In people with a normal immune system, the lung (pulmonary) form of cryptococcoses may be asymptomatic, but with impaired immune systems, the Cryptococcus spp. may disseminate to the meninges causing life-threatening meningoencephalitis [7]

Methods

Results

Discussion

Conclusion