NAIBI KEITOYO Amedé

Brucellosis is a major notifiable zoonotic disease that affects domestic, wild, and marine animals, as well as humans. It is caused by a bacterial infection of the genus Brucella. The objective of this study was to detect Brucella abortus in bovine hygromas and cow’s milk using conventional Polymerase Chain Reaction (PCR). Two primer pairs were used to amplify DNA fragments present in the collected samples. Gel electrophoresis results showed electrophoretic profiles for the Brucella abortus strain at approximately 223 base pairs and another strain at approximately 100 to 120 base pairs. Of 50 hygromas and 50 raw milk samples collected from cattle, 36 samples were PCR-positive, representing an overall prevalence of 72%. The study revealed a co-infection with Brucella abortus and Brucella melitensis, with a prevalence of 34.0%. Females were more frequently infected with Brucella abortus than males, with a rate of 76.2% in females and 50% in males. Transhumant cattle had an infection rate of 83.3%, while sedentary cattle had a rate of 65.6%, resulting in a crude odds ratio of 2.62 (χ²=1.021; p=0.312). Prevalence ranged from 52.9% (Medina villages) to 87.5% (Shilo camps). The study showed that two strains of Brucella abortus circulate in the Chari department with high prevalence. Control and prevention strategies will be necessary for effective management, as brucellosis is included on the Chadian government’s list of priority diseases to be monitored and eradicated. Keywords: Brucella abortus, hygroma, milk, Chad

Vaginal infections represent a major public health issue, particularly in developing countries where access to diagnostic and treatment services remains inadequate. The vagina is a complex microbiological ecosystem, normally dominated by lactobacilli, which play a protective role by maintaining an acidic pH and preventing the proliferation of pathogenic bacteria. Any disruption to this balance, known as vaginal dysbiosis, promotes the development of infections. These infections are among the most common reasons for gynaecological consultations among women of childbearing age. The aim of this study was to characterise the pathogens isolated from vaginal swabs taken from women attending the Bacteriology Laboratory at the University Hospital Centre for Mother and Child (CHU-ME) in N'Djamena between 15 October and 15 November 2025, and to establish their antimicrobial susceptibility profiles. A total of 99 vaginal swabs were collected and analysed using routine microbiological techniques. Women aged 20–29 were the most affected group (61.6%), with a mean age of 26 years. The prevalence of confirmed vaginal infection was 36.4%, with an overall microbiological positivity rate of 60.6%. Candida spp was common, accounting for 40.4% of cases, and co-infection with this organism was found in 32.3% of cases. Escherichia coli accounted for 3% of vaginal infections. According to antifungal susceptibility testing, Candida spp showed 90.9% susceptibility to Miconazole and 97.8% to Econazole, as well as 66.7% susceptibility to Fluconazole. Resistance was observed to Amphotericin B (95.6%) and Griseofulvin (95.7%). According to the antibiotic susceptibility testing carried out, Amikacin showed 100% susceptibility against Staphylococcus spp., making this aminoglycoside the most active agent against the staphylococci isolated in this study. Erythromycin and Gentamicin showed lower susceptibility rates of 67.9% and 60.7% respectively, although a 25.0% resistance rate to Erythromycin limits its use as a first-line treatment. Escherichia coli showed 100% susceptibility to Imipenem and Gentamicin, as well as 50% susceptibility to Ertapenem and Ciprofloxacin. However, it was resistant to Ceftriaxone (100%), Ampicillin (100%) and Nalidixic Acid (100%). Keywords: Vaginal infections, CHU-ME, N'Djamena.