Microbiology Research Journal International

Prevalence, Risk Factors and Susceptibility for Notiﬁable Typhoid and Paratyphoid among Patients Attending the Regional Hospital Bamenda, Cameroon

Gerald Ngo Teke — 2026-04-16

Background: Typhoid and paratyphoid are global diseases among the major public health concerns in developing countries, including Cameroon, especially in areas where tap water is not widely available. Understanding the burden and risk factors contributing to the transmission and proper diagnosis of the disease is crucial to applying appropriate preventive and therapeutic interventions. Hence we assessed the prevalence of notiﬁable typhoid and paratyphoid fever, its associated factors and susceptibility among febrile patients visiting Regional Hospital Bamenda, Cameroon.

Methodology: A facility-based cross-sectional study was employed among 199 febrile patients visiting Regional Hospital Bamenda for health services from May to July 2023. The data were collected using laboratory procedures (Widal test) and a structured interviewer-administered questionnaire. Blood and stool were collected from suspected patients for isolation and identification of bacteria. Susceptibility tests were done using standard drugs. The data were analyzed by SPSS version 25. The presence and strength of associations between variables were considered significant (p≤0.05). Drug sensitivity patterns to the isolates were established as susceptible, intermediate and/or resistant.

Results: The overall prevalence of typhoid was 51.2%. The females were in high number with the seroprevalences of 13.1% (S. typhi), 10.6% (S. paratyphi) and 9.5% (both S. typhi and paratyphi). Stool isolates showed varied sensitivity to fluoroquinolones (ofloxacin (17.6%), ciprofloxacin (23.5%) and levofloxacin (18.6%). Salmonella isolates were mostly resistant to amoxicillin (87.3%). Hygienic conditions (ꭓ² =19.85, p=0·001), Occupation (ꭓ² =14.55, p=0·001) and number of household occupants (ꭓ² =31.54, p<0·001) were significantly associated with typhoid fever infection.

Conclusion: The prevalence of typhoid fever among febrile patients was high. Typhoid fever infection was significantly associated with household occupants. Some participants had both S. typhi and S. paratyphi.

Genomic and Evolutionary Dynamic Surveillance of Mpox Diagnosed at the National Laboratory of Clinical Biology of Public Health in the Central African Republic

Hériter Obed Lango — 2026-04-25

The recent MPXV epidemic in Africa revealed significant viral diversity and complex transmission dynamics, warranting a sub-regional genomic study. We analysed 1,630 high-quality MPXV clade Ia genomes from seven Central African countries, revealing the complex and concurrent circulation of subclades Ia and Ib. Sub clade Ia showed high viral diversity in reservoir hosts, detected through zoonotic transmission and associated with a recently observed persistent human epidemic. In contrast, clade Ib showed evidence of sustained human-to-human transmission in East and Southern Africa. Similar to clade Ia, clade IIb exhibits ongoing zoonotic transmission and a persistent human epidemic linked to the circulation of G1 and G2 lineages. Phylogeographic analyses revealed frequent cross-border transmission and significant interconnectedness, consistent with human mobility corridors and international borders. For example, the Democratic Republic of Congo and Sierra Leone appear to be sources of regional exports, while the Cameroon-Nigeria, Central African Republic-Cameroon, and Central African Republic-DRC interfaces reflect ongoing cross-border zoonotic spillovers. These findings underscore the need for harmonised genomic surveillance, APOBEC3-based triage, and integrated One Health strategies to prevent the escalation of local outbreaks into regional epidemics and to guide vaccine deployment and public health preparedness.

Molecular Detection and Analysis of Carbapenemase Encoding Genes (NDM & OXA-48) in Clinical Strains of Klebsiella pneumoniae Isolated from Urine Samples

Pragati Singh — 2026-04-27

Carbapenem resistance among uropathogens is a growing public health concern due to the spread of carbapenemase genes such as blaNDM and blaOXA-48, which reduce the effectiveness of last-line β-lactam antibiotics. This study investigated the presence of these genes in bacteria isolated from urine samples of patients with suspected urinary tract infections (UTIs), with initial attention to presumptive Klebsiella pneumoniae isolates. Thirty urine samples were examined using physical, chemical, microscopic, cultural, biochemical, and molecular methods. Culture on Blood agar, MacConkey agar, CLED agar, and CHROM agar revealed diverse uropathogens. Escherichia coli was the predominant organism (61.12%), followed by Citrobacter spp., while only a few isolates appeared to be Klebsiella pneumoniae on chromogenic media. Biochemical testing confirmed just one isolate as K. pneumoniae, which was fully sensitive to carbapenems (imipenem, meropenem, doripenem). Genomic DNA from selected isolates was analyzed by End-Point PCR and Real-Time PCR targeting blaNDM and blaOXA-48. The blaNDM gene was detected in two pediatric samples, and blaOXA-48 in one of these. Importantly, these gene-positive isolates were not confirmed as K. pneumoniae, indicating the presence of carbapenemase genes in non-Klebsiella uropathogens. The findings demonstrate silent circulation of carbapenemase genes in urinary bacteria without phenotypic carbapenem resistance. Such isolates may act as hidden reservoirs for resistance transfer under antibiotic pressure. This study underscores the need for molecular surveillance alongside routine susceptibility testing to identify early dissemination of antimicrobial resistance in clinical settings.

Essential Oils of Melaleuca leucadendra and Melaleuca quinquenervia: Chemical Composition and Efficacy Level in Controlling in Vitro Isolates of Potentially Aflatoxin-Producing Aspergillus flavus

Safietou Sabaly — 2026-04-28

Among the mycotoxins of health and economic importance, aflatoxins hold a prominent place. This study aims to determine the chemical composition of the essential oils of Melaleuca leucadendra and Melaleuca quinquenervia, and to evaluate their effectiveness in the in vitro control of an Aspergillus flavus strain isolated from peanut seeds in Senegal. Essential oils were extracted from air-dried leaves collected in Fatick and the Mbao Classified Forest using hydrodistillation with a Clevenger-type apparatus. Chemical characterisation was performed using gas chromatography (GC-FID) and gas chromatography–mass spectrometry (GC-MS). Data were statistically analyzed using ANOVA and Student–Newman–Keuls tests at a 5% significance level. The chemical composition analysis of the essential oils revealed high identification rates of 96.8% for Melaleuca quinquenervia and 99.9% for Melaleuca leucadendra. The antifungal assays demonstrated a strong dose-dependent inhibitory effect of both essential oils against Aspergillus flavus ThC2. M. quinquenervia exhibited the highest activity, with inhibition rates ranging from 71.8% at 100 ppm to 92.3% at 1000 ppm. M. leucadendra showed moderate activity, with inhibition ranging from 44.2% to 63.0% across the same concentrations. Overall, the results indicate that both essential oils, particularly that of M. quinquenervia, exhibit strong antifungal potential against A. flavus. Essential oils derived from Melaleuca quinquenervia and Melaleuca leucadendra exhibit distinct chemical compositions that contribute to notable biological activities. These oils demonstrate strong inhibitory effects on mycelial growth and sporulation of Aspergillus flavus, along with a moderate capacity to reduce aflatoxin biosynthesis. Owing to their diverse bioactive compounds and multi-target mechanisms of action, certain essential oils display antimicrobial properties that can surpass those of conventional synthetic agents while reducing the likelihood of resistance development in microorganisms. Consequently, these natural products show significant potential as effective alternatives in integrated biological control strategies aimed at managing crop and stored-product pathogens, particularly aflatoxin-producing fungi.

Phenotypic Characterization of Mycotoxigenic Fungi Isolated from Palm Oil Sold Within Bauchi Metropolis, Nigeria

H. M. Ghazali — 2026-05-06

Background and Aim: Palm oil is widely consumed in Nigeria, but poor handling, storage, and marketing conditions predispose it to fungal contamination and mycotoxin production, posing public health risks. This study aimed to phenotypically characterize mycotoxigenic fungi isolated from palm oil sold within Bauchi metropolis and assess their fungal load as well as the physicochemical quality.

Place and Duration of Study: The study was carried out in Bauchi Metropolis, Bauchi State, Nigeria, using palm oil samples collected from Wunti, Muda Lawal, Central, and Yelwa markets. Laboratory analyses were conducted at the Microbiology Laboratory, Abubakar Tafawa Balewa University (ATBU), Bauchi.

Methodology: A total of 100 palm oil samples were randomly collected (25 per market). Fungi were isolated using the direct plating method on Potato Dextrose Agar supplemented with chloramphenicol. Phenotypic identification was based on macroscopic and microscopic characteristics. Fungal load was determined using the colony-forming unit (CFU/g) method. Physicochemical properties (density, viscosity, color, tactile quality, and moisture content) were analyzed using AOAC standard procedures.

Results: Seven fungal taxa were identified, with Fusarium species showing the highest prevalence (42.5%), followed by Aspergillus niger (17.5%), A. parasiticus (12.5%), A. flavus (10.0%), Penicillium species (10.0%), A. fumigatus (5.0%), and Mucor species (2.5%). Mean fungal loads ranged from 3.1 × 10⁶ to 1.0 × 10⁷ CFU/g, exceeding recommended microbial limits for edible oils. Physicochemical parameters largely fell within acceptable standards, though variations suggested differences in handling and storage practices among markets.

Conclusion: Palm oil sold in Bauchi metropolis is contaminated with potentially mycotoxigenic fungi, particularly Fusarium and Aspergillus species, at levels that may pose health risks. Although physicochemical quality was generally acceptable, high fungal loads indicate poor hygienic practices. Improved processing, storage, and regulatory monitoring are necessary to ensure consumer safety.

Molecular Identification of Antibiotics Resistance Bacteria Isolated from Untreated Water Sources Fed into Sokoto Water Board for Municipal Consumption, Sokoto State, Nigeria

Salisu Hussaini — 2026-05-08

Water quality is essential for life, but contamination from heavy metals and antibiotic-resistant microorganisms in aquatic environments poses serious risks to human health and ecosystems. This study evaluated the microbiological quality of untreated water sources fed into in Sokoto water board, to assess water suitability for consumption and potential public health risks. A total of 15 water samples were collected from five locations these includes; Sokoto mechanic village, Tudun Wada, Waziri C, Tashar Illela garage and water board pre-treatment and analysed for microbial quality which involved bacterial isolation and identification, and antimicrobial susceptibility testing biochemical test and the Kirby-Bauer method. Isolates exhibiting high resistance profiles were further subjected to molecular identification. Nine bacterial species were isolated and identified, with the highest frequencies attributed to Escherichia coli (43.5%), Staphylococcus aureus (37.25%), and Pseudomonas aeruginosa (31%). Antimicrobial susceptibility testing showed alarming resistance, particularly in E. coli and Pseudomonas aeruginosa which was highly resistant to Septrin (100%), ciprofloxacin (80%), levofloxacin (80%), and amoxicillin/augmentin (60-75%). Further molecular analysis of multi-drug-resistant strains identified emergent pathogens such as Aeromonas bivalvium and Psychrobacter sanguinis. This study underscores the significant public health risk posed by highly contaminated water fed into Sokoto water board, driven by the widespread presence of multi-drug resistant (MDR) bacteria.