Characterization of Mycobacterium orygis, Mycobacterium bovis, and Mycobacterium caprae Infections in Humans in Western Canada.

Epidemiologic research on zoonotic tuberculosis historically used Mycobacterium bovis as a surrogate measure, however, increased reports of human tuberculosis caused by other animal-associated Mycobacterium tuberculosis complex members like Mycobacterium orygis necessitates their inclusion. We performed a retrospective cohort study including persons infected with any animal-lineage M. tuberculosis complex species in Alberta, Canada, from January 1995 to July 2021, identifying 42 patients (20 M. bovis, 21 M. orygis, one M. caprae). Demographic, epidemiologic and clinical characteristics were compared against persons with culture-confirmed M. tuberculosis infection. The proportion of culture-positive infections caused by M. orygis increased continuously from 2016-2020. Significantly more females at a higher median age were impacted by M. orygis, with all patients originating from South Asia. M. bovis caused significantly more extra-pulmonary disease, and disproportionately impacted young females, particularly those pregnant or post-partum. All infections were acquired abroad. These findings can aid in developing targeted public health interventions.

Whole genome sequencing-based identification of human tuberculosis caused by animal-lineage Mycobacterium orygis.

A recently described member of the Mycobacterium tuberculosis complex (MTBC) is Mycobacterium orygis, which can cause disease primarily in animals but also in humans. Although M. orygis has been reported from different geographic regions around the world, due to a lack of proper identification techniques, the contribution of this emerging pathogen to the global burden of zoonotic tuberculosis is not fully understood. In the present work, we report single nucleotide polymorphism (SNP) analysis using whole genome sequencing (WGS) that can accurately identify M. orygis and differentiate it from other members of the MTBC species. WGS-based SNP analysis was performed for 61 isolates from different provinces in Canada that were identified as M. orygis. A total of 56 M. orygis sequences from the public databases were also included in the analysis. Several unique SNPs in the gyrB, PPE55, Rv2042c, leuS, mmpL6, and mmpS6 genes were used to determine their effectiveness as genetic markers for the identification of M. orygis. To the best of our knowledge, five of these SNPs, viz., gyrB 277 (A→G), gyrB 1478 (T→C), leuS 1064 (A→T), mmpL6 486 (T→C), and mmpS6 334 (C→G), are reported for the first time in this study. Our results also revealed several SNPs specific to other species within MTBC. The phylogenetic analysis shows that the studied genomes were genetically diverse and clustered with M. orygis sequences of human and animal origin reported from different geographic locations. Therefore, the present study provides a new insight into the high-confidence identification of M. orygis from MTBC species based on WGS data, which can be useful for reference and diagnostic laboratories.

Canadian multicenter laboratory study for standardized second-line antimicrobial susceptibility testing of Mycobacterium tuberculosis.

The purpose of this study was to establish a standardized protocol for second-line antimicrobial susceptibility testing of Mycobacterium tuberculosis using the Bactec MGIT 960 system in Canadian laboratories. Four Canadian public health laboratories compared the susceptibility testing results of 9 second-line antimicrobials between the Bactec 460 and Bactec MGIT 960 systems. Based on the data generated, we have established that the Bactec MGIT 960 system provides results comparable to those obtained with the previous Bactec 460 method. The critical concentrations established for the testing of the antimicrobials used are as follows: amikacin, 1 µg/ml; capreomycin, 2.5 µg/ml; ethionamide, 5 µg/ml; kanamycin, 2.5 µg/ml; linezolid, 1 µg/ml; moxifloxacin, 0.25 µg/ml; ofloxacin, 2 µg/ml; p-aminosalicylic acid, 4 µg/ml; rifabutin, 0.5 µg/ml.

Mycobacterium senegalense tissue infection in a child after fish tank exposure.

The present report describes the first known case of an otherwise healthy child who developed a soft tissue infection due to Mycobacterium senegalense - a pathogen usually found in east Africa that is responsible for infecting various animals. The patient presented with nonhealing wounds after sustaining facial lacerations from the shattered glass of a fish tank. The patient responded well to scar revision and antibiotics, with no subsequent relapse.

Empirical treatment of community-acquired pneumonia and the development of fluoroquinolone-resistant tuberculosis.

UNLABELLED: BACKGROUND" Fluoroquinolone (FLQ) antibiotics are not uncommonly prescribed for community-acquired pneumonia that is later proven to be pulmonary tuberculosis (TB). Such FLQ monotherapy may result in FLQ-resistant pulmonary TB. METHODS: To assess outpatient FLQ use by patients with culture-proven pulmonary TB before diagnosis, TB registries in Alberta and Saskatchewan, Canada, were linked with provincial and federal drug benefit plans. To assess FLQ resistance, a case-control study was performed. RESULTS: Of 428 patients with pulmonary TB who were covered by a drug benefit plan, 74 (17.3%) had received > or = 1 FLQ prescription during the 6 months immediately before receipt of the diagnosis. Older patients (age, >64 years) were more likely than younger patients (age, 15-64 years) to be prescribed an FLQ (P < .05). Patients who were prescribed an FLQ received a total of 103 prescriptions. Most (54 [73.0%] of 74) patients who were prescribed an FLQ received a single prescription. Most (69 [67.0%] of 103) FLQ prescriptions were written within 90 days before the diagnosis of pulmonary TB. Patients who were prescribed an FLQ were not statistically significantly more likely than matched patients who were not prescribed an FLQ (control subjects) to be infected with FLQ-resistant Mycobacterium tuberculosis. Of 148 isolates of M. tuberculosis from patients and control subjects, 3 were FLQ resistant; all of these isolates were from patients who had received multiple FLQ prescriptions. Patients who had received multiple FLQ prescriptions were more likely than patients who had received a single FLQ prescription to be infected with FLQ-resistant M. tuberculosis (15.0% vs. 0.0%; odds ratio, 11.4; P = .04). CONCLUSIONS: Outpatient FLQ use, ostensibly for community-acquired pneumonia, is not uncommon among patients with pulmonary TB, especially older patients. Single FLQ prescriptions were not associated with FLQ-resistant M. tuberculosis, whereas multiple FLQ prescriptions were associated with FLQ resistance.

Clinical, microbiological, and epidemiological findings of an outbreak of Mycobacterium abscessus hand-and-foot disease.

In 2003, we identified an outbreak of clinically distinct lesions involving the hands and feet associated with a public wading pool in Edmonton, Alberta, Canada. A total of 85 cases were identified. The management and follow-up of 41 children and 1 adult patients is presented. Skin lesions occurred within a median incubation period of 29 days and approximately 88 days for the adult patient. Lesions resolved within a median of 58 days and approximately 150 days for the adult patient. Patients were treated with clarithromycin, topical antibiotic dressings, and/or incision and drainage of pustules or followed without treatment. All resolved without complication. The pool was closed and cleaned. The M. abscessus hand-and-foot disease is characterized by the onset, mainly in children, of tender, erythematous papules, pustules, and abscesses with a self-limited course. This is the first documented M. abscessus outbreak associated with wading pool exposure.