The incidence of opportunistic fungi in patients suspected of tuberculosis

Status of pulmonary fungal pathogens among individuals with clinical features of pulmonary tuberculosis at Mbarara University Teaching Hospital in Southwestern Uganda

Background:

Pulmonary mycoses are important diseases of the respiratory tract caused by pulmonary fungal pathogens. These pathogens are responsible for significant morbidity and mortality rates worldwide; however, less attention has been paid to them. In this study we determined the prevalence of pulmonary fungal pathogens among individuals with clinical features of pulmonary tuberculosis at Mbarara Regional Referral Hospital.

Method:

This was a hospital based cross sectional survey. Sputum samples were collected from each study participant. For each sample, the following tests were performed: Sabouraud dextrose agar for fungal culture, GeneXpert for Mycobacteria tuberculosis (MTB) and potassium hydroxide for fungal screening. Filamentous fungal growth and yeasts were further examined with lactophenol cotton blue staining and germ tube respectively.

Results:

Out of 113 study participants, 80 (70.7%) had pulmonary fungal pathogens whilst those with pulmonary tuberculosis numbered five (4.4%). Candida albicans [21 (22.58%)] and Aspergillus species [16 (17.20%)] were the pathogens most identified among others. Two (1.7%) TB GeneXpert positive participants had fungal pathogens isolated from their sputum samples. We established a prevalence of 57 (71.3%) for pulmonary fungal pathogen (PFP) isolates, three (60.0%) for MTB in HIV positive patients and 18 (22.5%) for PFP, and zero (0.0%) for MTB in HIV negative patients. On the other hand, two (100%) HIV positive patients had both PFP isolates and MTB.

Conclusion:

Our findings highlight the diversity of neglected pulmonary fungal pathogens whose known medical importance in causing pulmonary mycoses cannot be overemphasised. Therefore this presents a need for routine diagnosis for pulmonary mycoses among TB suspects and set-up of antimicrobial profile for pulmonary fungal isolates to support clinical management of these cases.

Aspergillus coinfection among patients with pulmonary tuberculosis in Asia and Africa countries; A systematic review and meta-analysis of cross-sectional studies

Progress of the disease and prolonged treatment with antibiotics or immunosuppressive agents makes tuberculosis patients susceptible to fungal infections. This study aimed to determine the prevalence of pulmonary Aspergillus coinfection among patients with pulmonary tuberculosis in Asia and Africa. The present review of cross-sectional studies was conducted on the prevalence of pulmonary Aspergillus coinfection among patients with pulmonary tuberculosis according to the PRISMA Protocol. Literatures published online in English from January 2001 to March 2019 via key databases such as Web of Science, MEDLINE, PubMed, Scopus, and Cochrane Library were searched. The used MeSH and non-MeSH keywords were; "pulmonary fungal", "pulmonary coinfection", OR "Pulmonary mycosis", "pulmonary fungal infections/agents", OR "Polymicrobial infection", OR "Secondary infection", OR "Mixed infections", "pulmonary aspergillosis", "fungi coinfection", "Fungal co-colonization", AND "pulmonary tuberculosis", OR "pulmonary TB", AND "Asia" AND "Africa". Finally, data analyzed using Comprehensive Meta-Analysis software (CMA). The combined Aspergillus coinfection among patients with pulmonary tuberculosis was 15.4% (95% CI: 11.4-20.5), Q = 105.8 and Z = 9.57 in Asia and Africa. The most frequency of Aspergillus spp. was related to A. fumigatus with a combined prevalence of 57.6%. Most of the studies included in the present review showed a higher Aspergillus coinfection in the age group of 40 years and higher. Also, the existence of a correlation between increasing age and Aspergillus coinfection was reported (p < 0.05). The present review showed a high combined Aspergillus coinfection among patients with pulmonary tuberculosis in Asia and Africa. Also, amongst the Aspergillus spp., the most frequent was related to A. fumigatus.

Identification of Candida albicans and Candida dubliniensis Species Isolated from Bronchoalveolar Lavage Samples Using Genotypic and Phenotypic Methods

Background

Candida dubliniensis is a newly diagnosed species very similar to Candida albicans phenotypically and first discovered in the mouth of people with AIDS in 1995. Among the different phenotypic and genotypic methods, a cost-effective method should be selected which makes it possible to differentiate these similar species.

Materials and Methods

Polymerase chain reaction (PCR)-restriction fragment length polymorphism with MspI enzyme and the Duplex-PCR method were done by DNA extraction using boiling. The sequencing of the amplified ribosomal region was used to confirm the C. dubliniensis species. Direct examination and colony count of the yeasts were applied for bronchoalveolar lavage (BAL) samples and the growth rate of the yeasts were studied at 45°C. To understand the ability formation of chlamydoconidia in yeast isolates, they were separately cultured on the sunflower seed agar, wheat flour agar, and corn meal agar media.

Results

Fifty-nine (49.2%) yeast colonies were identified from the total of 120 BAL specimens. Twenty-nine isolated yeasts; including 17 (58.6%) of C. albicans/dubliniensis complex and 12 (41.4%) of nonalbicans isolates produced pseudohypha or blastoconidia in direct smear with a mean colony count of 42000 CFU/mL. C. albicans with the frequency of 15 (42.9%) were the most common isolated yeasts, whereas C. dubliniensis was identified in two nonHIV patients.

Conclusion

Sequencing of the replicated gene fragment is the best method for identifying the yeasts, but the determination of the species by phenotypic methods such as the creation of chlamydoconidia in sunflower seeds agar and wheat flour agar media can be cost-effective, have sensitivity and acceptable quality.

Effects of fluconazole on the clinical outcome and immune response in fungal co-infected tuberculosis patients

With overuse of the broad-spectrum antibiotics, the pulmonary fungal infection increasingly becomes the most common complication associated with senile pulmonary tuberculosis (TB) and attracts intensive attentions from clinicians. Here we presented the retrospective analysis of impact of fluconazole treatment on the clinical outcome and immune response in fungal co-infected tuberculosis patients. A randomized, double-blind, placebo-controlled trial of fluconazole (100 mg per day for consecutive weeks) in fungal-positive senile tuberculosis patients was conducted in our hospital. Peripheral eosinophil counts were computed by the automatic hematology analyzer. The secretory inflammatory cytokines interferon (IFN)-γ, tumor necrosis factor (TNF)-α and chemokines chemokine C-X-C motif ligand (CXCL)9, CXCL10, CXCL11 were determined with enzyme-linked immunosorbent assay kits. The peripheral T helper 1 cells (Th1) and regulatory T cells (Treg) population were analyzed by flow cytometry. None of significant difference in respect to baseline TB score was observed between placebo and fluconazole groups. Administration of fluconazole significantly stimulated eosinophils population and secretion of inflammatory cytokines IFN-γ and TNF-α. Simultaneously, the peripheral Th1% and chemokines including CXCL9, CSCL10, CXCL11 were markedly induced in response to fluconazole treatment. Fungal infection significantly affected host immunity during tuberculosis which was effectively reversed by fluconazole treatment.

The Effect of Polyherbal Medicines Used for the Treatment of Tuberculosis on Other Opportunistic Organisms of Humans Infected with Tuberculosis

Background:

In many immunocompromised patients, opportunistic bacterial and fungal infections are common. Polyherbal medicines examined in this study are used by the indigenous people of South Africa for the treatment of tuberculosis (TB) and other opportunistic infections associated with TB.

Objective:

To evaluate the antibacterial and antifungal activity of nine polyherbal remedies against four Gram-positive and Gram-negative bacteria respectively and three fungi.

Materials and Methods:

Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against the organisms.

Results:

The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that HBfs and FB remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL, followed by HBts remedy at 5.0 mg/mL. However, the MIC valves of KWTa, KWTb, KWTc, HBss, EL and AL remedies were higher than 5.0 mg/mL which was the highest concentration used. Only KWTa remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC value of 2.5 mg/mL. While KWTc and HBts had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL.

Conclusion:

This study revealed that some of these polyherbal formulations have activities against some of the opportunistic bacterial and fungal isolates associated with TB patients. The capability of these remedies to inhibit the organisms is an indication that they are a potential broad-spectrum antimicrobial agent. However, the remedies that are inactive might contain stimulant effects on the immune system.

SUMMARY

In the Eastern Cape Province of South Africa, no study has been reported on the effect of polyherbal remedies used for the treatment of TB on the opportunistic pathogen. This study therefore revealed that some of the polyherbal medicines possess activity against bacterial and fungal pathogens.

Abbreviations used: TB: Tuberculosis; MIC: Minimum Inhibitory Concentration; CFU/ML: Colony Forming Unit Per Mill.

Evaluation of APR1 Gene Expression in Candida albicans Strains Isolated From Patients With Multiple Sclerosis

BACKGROUND

Intracellular aspartic proteinase A enzyme is expressed by the APR1 gene and is one of the important factors in the development of systemic candidiasis caused by Candida albicans.

OBJECTIVES

The aim of this study was to evaluate the expression of the APR1 gene in C. albicans isolates obtained from patients with multiple sclerosis (MS) and from controls.

PATIENTS AND METHODS

The samples were obtained from 135 MS patients with candidiasis and 100 matched controls of healthy individuals during 2010 - 2011. The clinical and control isolates of C. albicans obtained from individuals were cultured onto sabouraud dextrose agar (SDA). The evaluation of APR1 gene expression was performed using the reverse transcriptase-polymerase chain reaction (RT-PCR) method.

RESULTS

There was a statistically significant difference in APR1 gene expression of C. albicans strains between MS patients (mean ± SD: 0.5208 ± 0.11518) and the control group (mean ± SD: 0.7603 ± 0.11405) (P = 0.000). Significant correlations were found between the APR1 gene expression of C. albicans strains from MS patients with regard to age and the expanded disability status scale (EDSS) (P = 0.000). The mean values of EDSS were 1.6074 ± 0.1081 after antifungal treatment and 2.2519 ± 0.1323 before antifungal treatment (P = 0.000). No significant correlation was observed between the APR1 gene expression with regard to sex and MS subtypes.

CONCLUSIONS

The results suggested that APR1 gene expression in C. albicans strains isolated from MS patients may be an important factor for invasive C. albicans strains in the progression of MS disease.

[Opportunistic yeast infections and enzymatic profile of the etiological agents]

Yeast infections are common in immunocompromised patients, although emerging species have been changing the epidemiological profile. The ability to secrete proteinases has been associated with pathogenicity within the genus Candida. This study had the aims of diagnosing yeast infections in immunocompromised patients and evaluating the virulence of the etiological agents, based on a proteinase secretion assay using bovine serum albumin as a substrate. Out of a total of 104 patients studied, 19 presented episodes of yeast infection. The respiratory tract (63.2%), followed by the urinary tract (10.5%), were the most common sites of infection. Candida albicans, Candida parapsilosis, Candida tropicalis and emerging species such as Candida krusei and Candida guilliermondii were isolated. Five isolates of Candida parapsilosis and one of Candida albicans and Candida guilliermondii exhibited high enzymatic activity. We conclude that enzymatic characterization of Candida isolates may be a useful prognostic marker, especially among immunocompromised individuals, since yeast infections in such patients are generally serious.