Non-tuberculous mycobacteria, not Mycobacterium bovis, are a significant cause of TB-like lesions observed in slaughtered cattle in Ghana.

Objectives: The aim was to isolate and identify the species of mycobacteria causing tuberculous-like (TB-like) lesions in cattle in Ghana. Methods: Between 2019 and 2020, 68 bovine tissue samples with TB-like lesions, identified during post slaughter examination, were obtained from four major abattoirs close to border towns in Ghana. The samples were cultured on Lowenstein-Jensen medium. Isolated bacteria were characterized by Ziehl-Neelsen staining and observation for acid-fast bacilli (AFB) under a microscope. DNA was extracted from AFB-positive isolates, and mycobacterial speciation was performed by line probe assay using GenoType Mycobacterium CM and also with mycobacterial 16S rRNA gene amplification and sequencing. Results: No Mycobacterium bovis was identified; however 53 bacterial isolates were obtained, of which 41 were non-tuberculous mycobacteria (NTM) strains and 12 were gram-positive bacteria. The predominant NTM species was M. fortuitum (43.9%, 18/41), with the rest being M. novocastrense, M. terrae, M. flavescens, M. holsaticum, M. cosmeticum, M. virginiense, M. intracellulare, M. mageritense, M. minnesotensis, M. duvalii, M. lehmannii, and M. koreense. Conclusions: In cattle, NTM contribute significantly to lesions observed during slaughter examination and may be an important cause of zoonotic tuberculosis. A One Health surveillance of NTM in Ghana would provide insights into their clinical significance.

Paradoxical reactions in Buruli ulcer after initiation of antibiotic therapy: Relationship to bacterial load.

BACKGROUND: We investigated the relationship between bacterial load in Buruli ulcer (BU) lesions and the development of paradoxical reaction following initiation of antibiotic treatment. METHODS: This was a longitudinal study involving BU patients from June 2013 to June 2017. Fine needle aspirates (FNA) and swab samples were obtained to establish the diagnosis of BU by PCR. Additional samples were obtained at baseline, during and after treatment (if the lesion had not healed) for microscopy, culture and combined 16S rRNA reverse transcriptase/ IS2404 qPCR assay. Patients were followed up at regular intervals until complete healing. RESULTS: Forty-seven of 354 patients (13%) with PCR confirmed BU had a PR, occurring between 2 and 42 (median 6) weeks after treatment initiation. The bacterial load, the proportion of patients with positive M. ulcerans culture (15/34 (44%) vs 29/119 (24%), p = 0.025) and the proportion with positive microscopy results (19/31 (61%) vs 28/90 (31%), p = 0.003) before initiation of treatment were significantly higher in the PR compared to the no PR group. Plaques (OR 5.12; 95% CI 2.26-11.61; p<0.001), oedematous (OR 4.23; 95% CI 1.43-12.5; p = 0.009) and category II lesions (OR 2.26; 95% CI 1.14-4.48; p = 0.02) were strongly associated with the occurrence of PR. The median time to complete healing (28 vs 13 weeks, p <0.001) was significantly longer in the PR group. CONCLUSIONS: Buruli ulcer patients who develop PR are characterized by high bacterial load in lesion samples taken at baseline and a higher rate of positive M. ulcerans culture. Occurrence of a PR was associated with delayed healing. TRIAL REGISTRATION: ClinicalTrials.gov NCT02153034.

Infection with Mansonella perstans Nematodes in Buruli Ulcer Patients, Ghana.

During August 2010-December 2012, we conducted a study of patients in Ghana who had Buruli ulcer, caused by Mycobacterium ulcerans, and found that 23% were co-infected with Mansonella perstans nematodes; 13% of controls also had M. perstans infection. M. perstans co-infection should be considered in the diagnosis and treatment of Buruli ulcer.