South Asian Journal of Research in Microbiology

Clostridium botulinum and Botulism: Epidemiology, Diagnosis, Treatment, Control and Prevention

Rhoda Nwalozie, Favour Ishmael Anthony — Sat, 06 Jun 2026 00:00:00 +0000

Clostridium botulinum is a Gram-positive, obligate anaerobic, spore-forming bacterium that produces botulinum toxin. It is one of the most potent neurotoxins known and this toxin causes botulism, a rare but life-threatening neuroparalytic disease characterized by descending flaccid paralysis and possible respiratory failure. Epidemiologically, botulism is characterized as a rare but high-severity neuroparalytic disease. Globally, the annual incidence remains low, typically under 1 case per 100,000 population, yet it carries a significant public health burden due to a case fatality rate (CFR) of 5–10% in developed health systems, rising to over 15% in resource-limited regions where antitoxins are scarce (Investigating the dual nature, 2026). Surveillance data from 2018 to 2025 indicates that global outbreaks are predominantly foodborne, often linked to home-canned products as seen in the 2024 BoNT/A outbreak in California and traditional fermented foods (MMWR, 2025). In Africa and West Africa, the morbidity is compounded by long-term sequelae; survivors report chronic fatigue (66.2%), general weakness (57.1%), and respiratory impairment (42.9%) persisting up to six years post-intoxication (Botulism Sequelae, 2025). Within Nigeria, C. botulinum is not a routinely notifiable disease under the NCDC surveillance framework, resulting in an absence of official prevalence figures across the 36 states, including Rivers State. However, clinical literature identifies high-risk practices in local food processing, suggesting significant under-reporting of cases. Although botulism occurs infrequently, its severity and association with food safety, infant health, wound infections, and therapeutic toxin use make it a significant public health concern. This review presents an overview of Clostridium botulinum, including its microbiological characteristics, toxin production, pathogenesis, clinical manifestations, diagnosis and control of botulism. Emphasis is placed on recent updates in diagnostic techniques, epidemiology, treatment, and public health control measures. Advances such as molecular diagnostic methods have improved early detection, while improved antitoxin availability and supportive care have reduced mortality rates. Additionally, the expanding medical and cosmetic use of botulinum toxin highlights the need for strict regulation and professional administration. Continuous public health surveillance, food safety practices, and health education remain vital in reducing disease burden.

Earthworm Pathology: An Overview of Diagnostic Approaches and Microbial Threats in Laboratory and Field Conditions

Lakshmi N. Gowda, C. Kavya, K. R. Shashank — Wed, 10 Jun 2026 00:00:00 +0000

Earthworms are vital ecosystem engineers that play fundamental roles in soil formation, nutrient cycling, organic matter decomposition, and the maintenance of soil fertility. Their ecological importance has led to the widespread adoption of vermiculture and vermicomposting technologies for sustainable waste management and agricultural productivity. However, the health and performance of earthworm populations can be adversely affected by a variety of diseases, parasites, pests, and environmental stressors that remain poorly documented and often overlooked. This review provides a comprehensive synthesis of current knowledge on the major biotic factors influencing earthworm health, with particular emphasis on economically important vermiculture species such as Eisenia fetida and Eudrilus eugeniae. The review examines bacterial diseases, fungal infections, viral associations, protozoan and helminthic parasites, and invertebrate pests including mites and predatory flatworms. In addition, physiological disorders associated with environmental stress, particularly acidic bed syndrome, moisture imbalance, poor aeration, and substrate deterioration, are discussed. The occurrence, symptoms, transmission pathways, ecological consequences, and management strategies associated with these health challenges are critically evaluated. Recent advances in microbiome research, metagenomics, and molecular diagnostics are highlighted for their potential to improve understanding of host–microbe interactions and disease detection in earthworm populations. The review also identifies significant knowledge gaps, including limited experimental validation of reported pathogens, inadequate disease surveillance, and insufficient information on disease dynamics under tropical vermiculture conditions. Emphasis is placed on integrated disease management, biosecurity measures, environmental monitoring, and sustainable vermiculture practices for maintaining healthy earthworm populations. By consolidating fragmented information and identifying future research priorities, this review serves as a valuable resource for researchers, soil biologists, and vermiculture practitioners working toward improved earthworm health, enhanced vermicomposting efficiency, and sustainable soil ecosystem management.

Knowledge, Attitudes, Practices and Challenges of Antimicrobial Stewardship among Nurses at the University of Benin Teaching Hospital, Benin City, Nigeria

Wed, 10 Jun 2026 00:00:00 +0000

Antimicrobial stewardship (AMS) is a strategy aimed at optimizing the use of antimicrobials to fight against resistance. This study aimed to assess the knowledge, attitudes, practices, and challenges of antimicrobial stewardship among nurses at the University of Benin Teaching Hospital, Benin City, Nigeria. A descriptive cross-sectional study design was used for this research. The sample size was determined using Cochrane’s formula, with adjustments for a 10% non-response rate, resulting in a final sample of 300. A multistage sampling technique was employed. Data was collected using a structured, self-administered questionnaire, adapted to assess knowledge, attitudes, challenges, adequacy of education and training and practices of nurses towards antimicrobial stewardship. Data was analyzed using IBM SPSS Version 26.0, with significance set at p<0.05. The majority (98.3%) of participants had good knowledge of antimicrobial stewardship. Knowledge of AMS was significantly associated with ethnicity and religion (p<0.05). The majority (94.7%) of respondents also had a good attitude towards antimicrobial stewardship. Males had better attitudes when compared to females (p<0=0.011). Also, Christians were 3.591 times more likely to have a good attitude compared to other religions (p=0.041). Regarding challenges in implementing antimicrobial stewardship, 124 (47.3%) respondents encountered moderate challenges, 71 (23.7%) experienced significant challenges, and 87 (29.0%) encountered minimal challenges. The majority of nurses (63.7%) believed that the level of training and education in AMS was inadequate. Two hundred and fifty-nine (86.3%) nurses demonstrated good practices in AMS. Age, gender and ethnicity were significantly associated with the practice of AMS (p<0.05) and were significant predictors of good practices of AMS among the nurses. In conclusion, most nurses in the hospital demonstrated good knowledge, attitude and practices of AMS. However, challenges were faced in implementation and the inadequacy of education and training in AMS.

Physicochemical and Bacteriological Quality Assessment of Well and Spring Water in the Fokontany of Ambatoharanana, Haute Matsiatra Region

Fri, 12 Jun 2026 00:00:00 +0000

Introduction: Access to safe drinking water remains a major public health challenge in rural areas of Madagascar, where groundwater sources are widely used despite limited information on their quality. This study aimed to evaluate the physicochemical and bacteriological quality of well and spring water consumed by the population of Ambatoharanana.

Methods: Two well water samples and two spring water samples were collected in polyethylene bottles and transported to the laboratory in a cooler maintained at 6°C. The samples were analyzed at the DREAH Haute Matsiatra laboratory. Parameters such as pH and temperature were measured in situ, while electrical conductivity, turbidity, manganese, iron, ammonium, aluminum, nitrite, nitrate, fluoride, and fecal coliforms were analyzed under laboratory conditions.

Results: The results reveal that both well and spring waters are environmentally polluted. The water is acidic (pH ranging from 4.59 to 6.15), likely due to the decomposition of organic matter in the soil. High levels of ammonium (0.93 mg/L for well 01; 0.57 mg/L for spring 01), aluminum (0.68 mg/L for well 02; 0.34 mg/L for spring 01), nitrite (0.105 mg/L for well 01), and nitrate (69.34 mg/L for well 02) indicate chemical pollution. Furthermore, the presence of fecal coliforms (ranging from 10 to 85 CFU/100 ml) confirms fecal contamination.

Conclusion: The quality of well and spring water is degraded by human activities, such as the use of chemical fertilizers and wastewater discharge near water points. Immediate measures, including chlorination, filtration, boiling, and public awareness campaigns on hygiene and contamination risks, are necessary to improve water safety.

Impact of Vaccination on Nasopharyngeal Carriage of Streptococcus pneumoniae in Children in Khana Local Government Area, Nigeria

F. Gobari Peace, Ollor A. Ollor, G. Nwokah Easter — Sat, 20 Jun 2026 00:00:00 +0000

Streptococcus pneumoniae remains a major cause of childhood morbidity and mortality globally, particularly in sub-Saharan Africa. Nasopharyngeal carriage in children is a precursor for invasive pneumococcal disease and serves as a reservoir for community transmission. Although pneumococcal conjugate vaccines (PCVs) have reduced pneumococcal disease, their effect on local carriage patterns in Nigerian communities remains underexplored. This study evaluated the impact of PCV immunisation on nasopharyngeal carriage of S. pneumoniae among children aged 0-5 years in Khana Local Government Area (LGA), Rivers State, Nigeria. A cross-sectional study was conducted among 200 preschool children recruited across ten communities in Khana LGA. Sociodemographic and vaccination information was collected using interviewer-guided questionnaires. Nasopharyngeal swabs were cultured on chocolate and blood agar, and isolates were identified using Gram staining and standard biochemical tests. Antimicrobial susceptibility testing was performed on recovered isolates. In addition, molecular testing (PCR) was conducted on 30 (15.0%) nasopharyngeal samples for pneumococcal gene detection. No S. pneumoniae carriage was detected by culture, and PCR similarly yielded no positive cases. In contrast, Staphylococcus spp. were identified in 43.0% of participants, with carriage differing significantly by location (p = 0.0005) but not by age, sex, school type, PCV immunisation status, or months since last antibiotic use. The antimicrobial susceptibility profile of Staphylococcus isolates showed the highest resistance to amoxicillin-clavulanic acid, cefepime, and clindamycin, each at 46.5%, with cefoxitin resistance in 32.6% and cefuroxime resistance in 19.8%. No resistance was detected to cefotaxime, meropenem, vancomycin, or erythromycin, while levofloxacin resistance was 1.2%. Pneumococcal carriage was not detected in this population by either culture or molecular methods, suggesting very low or absent carriage in the study setting, while highlighting substantial Staphylococcus carriage and noteworthy resistance to several commonly used antibiotics.