Brucella abortus and B . melitensis have been reported in several studies in animals in Zimbabwe but the extent of the disease remains poorly known. Thus, characterizing the circulating strains is a critical first step in understanding brucellosis in the country. In this study we used an array of molecular assays including AMOS-PCR, Bruce-ladder, multiple locus variable number tandem repeats analysis (MLVA) and single nucleotide polymorphisms from whole genome sequencing (WGS-SNP) to characterize Brucella isolates to the species, biovar, and individual strain level. Sixteen Brucella strains isolated in Zimbabwe at the Central Veterinary laboratory from various hosts were characterized using all or some of these assays. The strains were identified as B . ovis , B . abortus , B . canis and B . suis , with B . canis being the first report of this species in Zimbabwe. Zimbabwean strains identified as B . suis and B . abortus were further characterized with whole genome sequencing and were closely related to reference strains 1330 and 86/8/59, respectively. We demonstrate the range of different tests that can be performed from simple assays that can be run in laboratories lacking sophisticated instrumentation to whole genome analyses that currently require substantial expertise and infrastructure often not available in the developing world.

Introduction: Bacillus anthracis is the causative agent of anthrax, a disease endemic in regions of Northern Cape Province and Kruger National Park of South Africa. Accurate identification of virulent B. anthracis is essential but challenging due to its close relationship with other members of B. cereus group. This study characterized B. anthracis and Bacillus species that were recovered from animals and the environment where animals died of anthrax symptoms in southern Africa using a polyphasic approach. Methodology: For this purpose, 3 B. anthracis and 10 Bacillus isolates were subjected to microbiology tests, BiologOmniLog identification system (Biolog), 16S ribosomal RNA (rRNA) sequence analysis, polymerase chain reaction (PCR) detection of protective antigen (pag) and capsule (cap) regions, and real-time PCR using hybridization probes targeting chromosomal, pag, and capC genes. Results: The Bacillus isolates were non-hemolytic, non-motile, and susceptible to penicillin, which is typical of B. anthracis, but resistant to gamma phage, unlike typical B. anthracis. The Biolog system and 16S rRNA gene sequence analysis identified most of the Bacillus isolates as B. endophyticus (7 of 10). Conventional PCR revealed that most of the Bacillus isolates contained capBCA gene regions. This highlights the limitation of the specificity of conventional PCR and the fact that the real-time PCR is more specific and reliable for anthrax diagnosis. Conclusions: Real-time PCR, 16S rRNA sequencing, and confirmatory microbiology tests including phage resistance distinguished Bacillus isolates from B. anthracis in this study. Identification of B. anthracis should be done using a polyphasic approach.

One of the main global concerns is the usage and spread of antibiotic resistant Salmonella serovars. The animals, humans, and environmental components interact and contribute to the rapid emergence and spread of antimicrobial resistance, directly or indirectly. Therefore, this study aimed to determine antibiotic resistance (AR) profiles of Salmonella serotypes isolated from the environment, animals, and humans in South Africa by a systematic review and meta-analysis. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed to search four databases for studies published from 1980 to 2021, that reported the antibiotic resistance profiles of Salmonella serotypes isolated in South Africa. The AR was screened from 2930 Salmonella serotypes which were isolated from 6842 samples. The Western Cape province had high pooled prevalence estimates (PPE) of Salmonella isolates with AR profiles followed by North West, Gauteng, and Eastern Cape with 94.3%, 75.4%, 59.4%, and 46.2%, respectively. The high PPE and heterogeneity were observed from environmental samples [69.6 (95% CI: 41.7−88.3), Q = 303.643, I2 = 98.353, Q-P = 0.045], animals [41.9 (95% CI: 18.5–69.5), Q = 637.355, I2 = 98.745, Q-P = 0.577], as well as animals/environment [95.9 (95% CI: 5.4−100), Q = 55.253, I2 = 96.380, Q-P = 0.300]. The majority of the salmonella isolates were resistant to sulphonamides (92.0%), enrofloxacin and erythromycin (89.3%), oxytetracycline (77.4%), imipenem (72.6%), tetracycline (67.4%), as well as trimethoprim (52.2%), among the environment, animals, and humans. The level of multidrug-resistance recorded for Salmonella isolates was 28.5% in this review. This study has highlighted the occurrence of AR by Salmonella isolates from animals, humans, and environmental samples in South Africa and this calls for a consolidated “One Health” approach for antimicrobial resistance epidemiological research, as well as the formulation of necessary intervention measures to prevent further spread.

ObjectivesAnthrax is a disease with an age old history in Africa caused by the Gram-positive endospore forming soil bacterium Bacillus anthracis. Epizootics of wild ungulates occur annually in the enzootic region of Pafuri, Kruger National Park (KNP) in the Limpopo Province of South Africa. Rigorous routine surveillance and diagnostics in KNP, has not revealed these rare isolates since the 1990s, despite unabated annual outbreaks. In 2011 a cheetah was diagnosed as anthrax positive from a private game reserve in Limpopo Province and reported to State Veterinary Services for further investigation. Isolation, molecular diagnostics, whole genome sequencing and comparative genomics were carried out for B. anthracis KC2011.ResultsBacteriological and molecular diagnostics confirmed the isolate as B. anthracis. Subsequent typing and whole genome single nucleotide polymorphisms analysis indicated it clustered alongside B. anthracis SA A0091 in the B.Br.010 SNP branch. Unlike B. anthracis KrugerB strain, KC2011 strain has unique SNPs and represents a new branch in the B-clade. The isolation and genotypic characterisation of KC2011 demonstrates a gap in the reporting of anthrax outbreaks in the greater Limpopo province area. The identification of vulnerable and susceptible cheetah mortalities due to this strain has implications for conservation measures and disease control.Electronic supplementary materialThe online version of this article (10.1186/s13104-018-3366-x) contains supplementary material, which is available to authorized users.