Microbiology Research Journal International

Hospital Effluent Discharges as Dynamic Hotspots for Multidrug-resistant Pathogens: Sources, Selection, Dissemination, Surveillance and Control

Sat, 08 Aug 2026 00:00:00 +0000

Hospital effluent is widely described as a hotspot for antimicrobial resistance, yet the term hotspot is often used without distinguishing concentration, absolute load, clinical relevance, mobility, selection pressure, temporal variability or downstream exposure. This critical narrative review evaluates hospital wastewater as a dynamic ecological and infrastructural interface linking healthcare, sewerage systems, treatment processes and receiving environments. Literature published from 2000 to 1 June 2026 was identified through accessible scholarly indexes, institutional sources and citation searching, with foundational earlier work retained where necessary. The evidence consistently shows that hospital discharges can contain clinically important multidrug-resistant bacteria, antibiotic resistance genes, mobile genetic elements, antimicrobial residues, disinfectants and other co-selective agents. The strongest evidence concerns enrichment of carbapenem-resistant and extended-spectrum beta-lactamase-producing Gram-negative bacteria, localised selection under antibiotic exposure, and incomplete removal during wastewater treatment. Nevertheless, the magnitude and persistence of a hospital-specific signal vary substantially with hospital type, patient mix, prescribing practices, hydraulic dilution, sewer travel, treatment configuration, season and analytical method. Community wastewater may exceed hospital discharges in total antimicrobial-resistance load because of its much larger volume, while DNA-based detection alone cannot establish viability, pathogenicity, transfer or infection risk. Conventional and advanced treatments generally reduce bacterial and genetic loads, but performance is process-specific and may be obscured by relative-abundance metrics, extracellular DNA, regrowth and survivor selection. The review proposes that hotspot status should be judged through an integrated framework combining hazard intensity, clinically relevant host-gene linkage, evolutionary opportunity, temporal dynamics and exposure connectivity. Risk-tiered source control, better hospital stewardship, longitudinal flow-weighted surveillance, host-resolved genomics and outcome-linked intervention studies are more defensible than universal assumptions about on-site treatment. Hospital effluent is therefore an important but context-dependent control point within a wider One Health antimicrobial-resistance system.

Bioremediation of Petroleum Hydrocarbon Contaminated Soil by Balanites aegyptiaca (L) Del and its Rhizospheric Bacteria

Amel Hassan Abdullah, Adil Ali Elhussein, Dafallah Ali Ibrahim, Azhary H. Nour — Mon, 27 Jul 2026 00:00:00 +0000

Phytoremediation is an emerging technology for cleaning crude-oil-contaminated soil. The aim of this study was to test the leguminous plant Balanites aegyptiaca (L.) Del. for its efficiency in remediating soil polluted with 0.5%, 1.0%, 1.5% and 2.0% (w/w) crude oil and its ability to enhance the activity of soil microorganisms. Standard methods were used to measure plant parameters, degradation percentage, total petroleum hydrocarbons and bacterial count. The results showed that crude oil concentration did not adversely affect plant growth, indicating the potential success of the phytoremediation process. Shoot length was not negatively affected by oil, compared with the control plant, up to a concentration of 1.5% for six months. Crude oil degradation percentages ranged from 49% to 74%. The highest degradation percentage was recorded in soil collected from beneath Balanites aegyptiaca (L.) Del. seedlings (74%). Viable microorganism counts in oil-contaminated soil at all tested concentrations were significantly (P <= 0.01) higher than those in oil-free soil at each sampling interval. The high biodegradation efficiency achieved using Balanites aegyptiaca (L.) Del. indicates a possible plant-associated mechanism for remediating crude-oil-contaminated soil. Balanites aegyptiaca could be used to clean up oil-contaminated soil after further testing under field conditions.

Assessment of Cooked Ready-To-Eat Fermented Cassava Product Marketed in Enugu State, Nigeria: Microbial Quality, Aflatoxin Occurrence, and Cyanide Levels

Ujunwa Felicia Nwachukwu, Ijeoma Chinenye Chioke, Oluchi Sandra Okolie — Wed, 29 Jul 2026 00:00:00 +0000

Cooked ready-to-eat fermented cassava products (akpu/fufu) are widely consumed in Nigeria because they are affordable and constitute an important source of dietary energy. However, contamination during processing, storage, transportation, and marketing may compromise their microbiological and chemical safety. This study assessed the microbial quality, aflatoxin occurrence, and cyanide levels of cooked ready-to-eat fermented cassava marketed in Enugu State, Nigeria. Samples were collected from Mayor Local Market, Enugu State, and analyzed using standard microbiological and chemical methods. The total aerobic mesophilic bacterial count was determined using standard culture techniques, while isolates were characterized by colony morphology, Gram staining, biochemical tests, and lactophenol cotton blue staining. The isolates were further identified by 16S rRNA and internal transcribed spacer (ITS) gene sequencing. Cyanide concentration was determined using the alkaline picrate spectrophotometric method, while aflatoxins were analyzed by affinity chromatography and high-performance liquid chromatography (HPLC). Molecular characterization identified the isolates as Lactiplantibacillus plantarum and Candida tropicalis. Hydrogen cyanide was detected in all the assayed samples, with the highest concentration observed in Sample A (56.12 mg/kg), followed by Sample D (56.08 mg/kg), Sample B (52.43 mg/kg), and Sample E (52.38 mg/kg), while the lowest concentration was recorded in Sample C (52.32 mg/kg). Aflatoxins B1, B2, G1, and G2 were detected at low concentrations, whereas aflatoxins M1 and M2 were not detected in any of the samples assessed. The total quantified aflatoxin concentrations were 4.35785 × 10⁻² µg/kg, 4.31180 × 10⁻² µg/kg, 4.40200 × 10⁻² µg/kg, 4.33810 × 10⁻² µg/kg, and 4.37010 × 10⁻² µg/kg for Samples A, B, C, D, and E, respectively. The total aerobic mesophilic bacterial count, aflatoxin concentrations, and cyanide levels did not differ significantly among the assessed cooked ready-to-eat fermented cassava samples (p > 0.05). The low level of aflatoxin contamination and the high cyanide levels present a potential public health concern. Therefore, improved processing practices, adequate fermentation, and proper heat treatment are recommended to reduce cyanide content and enhance the safety of ready-to-eat fermented cassava products.

Efficacy of Fungicides against Spot Blotch Disease of Wheat Caused by Bipolaris sorokiniana (Sacc.) Shoemaker

Thu, 30 Jul 2026 00:00:00 +0000

Spot blotch, caused by Bipolaris sorokiniana, is one of the most destructive foliar diseases limiting wheat productivity, particularly under the warm and humid conditions of the Indo-Gangetic Plains. The present study was conducted during the 2024-25 Rabi season at the Norman E. Borlaug Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, to evaluate the efficacy of different fungicides against spot blotch under field conditions. The experiment comprised eight fungicidal treatments, including triazoles, strobilurins, their combinations, and a contact fungicide, together with an untreated control. Two foliar sprays were applied at 10-day intervals after disease initiation. Disease severity was assessed as percentage disease intensity (PDI), while grain yield and the percentage increase in yield over the untreated control were recorded. Among the treatments, tebuconazole 50% + trifloxystrobin 25% (0.10%) was the most effective in reducing disease severity and increasing yield. The findings indicate that triazole-strobilurin combination fungicides provided better management of spot blotch, which may be associated with their complementary preventive and curative modes of action and systemic activity.

Antimicrobial Resistance and Virulence Profiles of Staphylococcus aureus and Escherichia coli Strains Isolated from Tchakpalo: A Traditional Beninese Beer

Mon, 03 Aug 2026 00:00:00 +0000

Background and Aim: Tchakpalo is an emblematic traditional beer within Benin's brewing heritage, and its artisanal production processes may favour contamination by potentially pathogenic and spoilage bacteria. This study evaluated the antibiotic resistance profiles and selected virulence factors of S. aureus (n = 50) and E. coli (n = 40) strains isolated from Tchakpalo.

Study Design and Methodology: Antibiotic susceptibility was evaluated using the Kirby-Bauer disc diffusion method according to CA-SFM and CLSI recommendations. Virulence factors, including biofilm-forming capacity, haemolytic activity and extended-spectrum beta-lactamase (ESBL) production, were determined using standardised phenotypic methods.

Results: Both bacterial species exhibited resistance to several antibiotics. S. aureus strains showed high resistance (≥70%) to ampicillin, erythromycin, clindamycin and kanamycin. In contrast, low resistance (≤30%) was observed for linezolid, quinupristin-dalfopristin, vancomycin, ciprofloxacin and rifampicin. All E. coli strains were resistant to ampicillin, ertapenem and fosfomycin. Resistance to amoxicillin-clavulanic acid and aztreonam was 90% and 75%, respectively, whereas resistance to gentamicin was 17.5%. Strong biofilm-forming capacity was observed in 74% of S. aureus and 47.5% of E. coli strains. The β-haemolytic phenotype predominated in both species, occurring in 62% of S. aureus and 55% of E. coli strains. Furthermore, 37.5% of E. coli strains produced ESBLs.

Conclusion: Tchakpalo may harbour antimicrobial-resistant bacteria with phenotypic characteristics associated with persistence and virulence. These findings support the need to strengthen hygiene practices throughout production and to implement appropriate surveillance to improve consumer food safety.

Phenotypic Characterization of Methicillin-Resistant Staphylococcus spp (MRS) Strains Isolated from Diabetic Foot Wounds at Yaounde Central Hospital

Sat, 08 Aug 2026 00:00:00 +0000

Background: Diabetic foot infections are a major public health concern and are frequently complicated by multidrug-resistant bacteria. Staphylococci, particularly methicillin-resistant strains (MRS), are among the most commonly encountered pathogens.

Aim: This study aimed to determine the prevalence of MRS in diabetic foot wounds, characterise their resistance profiles, and identify phenotypes associated with multidrug resistance.

Methods: A cross-sectional study was conducted among 112 patients with diabetic foot wounds at Yaoundé Central Hospital between March and July 2021. Samples were analysed using culture, biochemical identification (API Staph), and disc-diffusion susceptibility testing. hVISA and GISA phenotypes were screened using the ROSCO method. Data were analysed using Epi InfoTM7 and Excel software, with statistical significance set at p < 0.05.

MRS were detected in 60.71% (68/112) of samples. The highest resistance rates were observed for β-lactams (99.26%) and aminoglycosides (91.17%), whereas nitrofurantoin (97.08%) and rifampicin (79.4%) showed the highest susceptibility rates. Among the 68 isolates, 25 (36.76%) were multidrug-resistant to more than seven antibiotic families (p = 0.001). The most frequent species were S. hominis (28%), S. epidermidis (16%), and S. xylosus (16%). GISA (60%) and hVISA (36%) phenotypes were detected, and some strains were also resistant to daptomycin.

Conclusion: Methicillin resistance in diabetic foot infections in Cameroon is not restricted to S. aureus but also involves clinically significant coagulase-negative staphylococci. These findings support expanded antimicrobial resistance surveillance and the adaptation of therapeutic protocols to local resistance patterns.

Microbial Remediation of Cyanogenic Glycosides and Valorisation of Cassava Mash Using Lactococcus lactis (PX273919) during Garri Production

Mon, 10 Aug 2026 00:00:00 +0000

Garri is a fermented cassava product in which cyanogenic glycosides may remain a food-safety concern when processing is inadequate. This study evaluated cyanide remediation and cassava-mash valorisation during garri production using Lactococcus lactis (PX273919). Bacterial isolates from fermented cassava mash were characterised by standard microbiological and molecular procedures, and L. lactis (PX273919) was selected for bioaugmentation. Cassava mash (250 g) was inoculated with 2.5 mL of culture at 2.0 × 10⁵ CFU/mL and assessed during fermentation. Cyanide was determined using the alkaline picrate method and infrared spectroscopy, while proximate composition was evaluated to assess nutritional changes. Initial cassava mash contained 0.085% cyanide, which decreased to 0.064% in unfermented garri. After 24 h, cyanide was 0.048% in L. lactis-treated garri compared with 0.063% in the untreated control. After 48 h, corresponding values were 0.052% and 0.062%, respectively. Infrared spectra showed nitrile absorption bands in cassava mash and garri samples, indicating residual cyanide after processing. Proximate composition varied with treatment and fermentation time; at 48 h, treated garri contained 2.19% protein, 1.5% fat and 86.86% carbohydrate. Energy values also differed between treated and untreated garri at 48 h. Overall, fermentation with L. lactis (PX273919) was associated with lower cyanide concentrations than untreated garri while supporting changes in proximate composition during garri production.

Assessment of Tuberculosis Laboratory Capacity within Meru Municipality in Meru County, Kenya

David Mwenya Nakitare — Mon, 10 Aug 2026 00:00:00 +0000

Tuberculosis (TB) remains an important public health concern, and timely laboratory diagnosis is essential for effective case detection and disease control. This cross-sectional study assessed TB diagnostic laboratory capacity in selected laboratories within Meru Municipality, Meru County, Kenya. Twenty-six laboratory technicians/technologists from nine laboratories were selected using stratified random sampling. Data were collected using a semi-structured questionnaire and an observational checklist covering laboratory infrastructure, diagnostic tests, equipment, reagents, record management, laboratory information systems and internet access. Chi-square analysis was used to assess differences between selected study variables. All assessed laboratories offered Ziehl-Neelsen staining (100%, n = 9), and all respondents reported availability of microscopes, electricity, running water and Ziehl-Neelsen reagents. Most respondents reported TB record management (88.5%, n = 23), laboratory information system availability (84.6%, n = 22), internet access (76.9%, n = 20) and centrifuges (84.6%, n = 22). However, no laboratory offered PCR restriction enzyme assay or sputum TB culture and sensitivity testing. Fluorescence microscopy and the Gene Xpert assay were each available in one laboratory (11.1%, n = 1). Public laboratories showed comparatively stronger TB diagnostic capacity than private commercial laboratories. The findings indicate basic microscopy-based capacity but notable gaps in molecular, culture and drug-susceptibility testing capacity.

Prevalence, Virulence and Antimicrobial Resistance Profiles of Listeria monocytogenes in Raw Cow’s Milk from Côte d’Ivoire: Implications for Food Safety

Fri, 21 Aug 2026 00:00:00 +0000

Aims: The consumption of raw milk, although widespread, is a major public health concern due to the risk of contamination by pathogenic microorganisms. The aim of this study was to characterise the Listeria monocytogenes strains isolated from raw cow’s milk in Côte d’Ivoire.

Methodology: For this purpose, 144 samples of raw cow’s milk were collected from the three main production regions (Abidjan, Bouaké and Korhogo). Listeria spp. were isolated and then identified using PCR-based methods, followed by sequencing of the 16S rDNA region to confirm species identification. The virulence genes (prfA, hly and actA) and antimicrobial resistance of the Listeria monocytogenes isolates were determined.

Results: Listeria monocytogenes was detected in 18 of 144 raw cow’s milk samples, corresponding to an overall prevalence of 12.5%. Each virulence gene was detected in 13 (72.2%) of the 18 strains tested, and 11 strains (61.1%) exhibited a complete virulence profile. Antibiotic resistance varied according to the antibiotic class. Resistance to erythromycin, a macrolide, was observed in 44.4% of the strains, while 55.6% exhibited resistance to trimethoprim–sulfamethoxazole. Among the β-lactams, 33.3% of the strains were resistant to ampicillin. In contrast, the particularly high resistance rate to meropenem (94.4%) observed among the tested strains is concerning and warrants particular attention.

Conclusion: The detection of L. monocytogenes in raw cow’s milk marketed in Côte d’Ivoire, together with the high prevalence of antimicrobial resistance observed among the tested strains, highlights the potential role of raw milk as a vehicle for the transmission of pathogenic and antimicrobial-resistant bacteria. Regular microbiological surveillance and the implementation of good hygienic practices are essential to improve the microbiological safety of raw milk and dairy products.