Author: Dr. Chika Ejikeugwu

Dr. Chika Ejikeugwu is a distinguished Microbiologist, Researcher, and Educator with an extensive international profile. He is a Fellow of the Alexander von Humboldt (AvH) Foundation, Germany, and currently serves as a Research Fellow at the Brandenburg University of Technology (BTU) Cottbus-Senftenberg, Germany. His research focuses on antimicrobial resistance (AMR) and the ecological impacts of antibiotics, with particular emphasis on soil ecosystems. He is the founder and developer of Africa’s leading microbiology platform, www.MicrobiologyClass.net, a widely recognized knowledge hub that supports students, professionals, and researchers across Africa and beyond. The platform is a key resource for advancing microbiology education and research with global reach and relevance. Throughout his career, Dr. Ejikeugwu has held several prestigious international research appointments and fellowships, including a Research Fellowship at the Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany, within the soilRESIST project, where he investigated the effects of antibiotic mixtures on soil microbiomes. He has also completed postdoctoral fellowships at the Federal Institute for Materials Research and Testing (BAM), Berlin, Germany, under the DAAD program, and at Kyoto University, Kyoto, Japan, under the MIF fellowship scheme. In recognition of his contributions to AMR research, he received the Young Investigator Award on AMR from Institut Mérieux, France, in 2021. He is also a recipient of the NIH CAMRA grant supporting research on AMR in poultry environments. Dr. Ejikeugwu was a member of the Global Young Academy (GYA), Germany, and holds memberships in several professional organizations, including Applied Microbiology International (AMI), the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), the American Society for Microbiology (ASM), and the Nigerian Society for Microbiology (NSM). He earned his PhD. in Pharmaceutical Microbiology and Biotechnology in 2017 from Nnamdi Azikiwe University, Nigeria. In his current role as Reader at ESUT, Nigeria, he is deeply engaged in teaching, mentorship, and research leadership. He supervises undergraduate and postgraduate students, fostering academic development and strengthening capacity in microbiology and AMR research. Driven by a sustained commitment to scientific excellence, education, and international collaboration, Dr. Ejikeugwu continues to contribute significantly to the advancement of microbiology and AMR research worldwide.

STREPTOCOCCUS PNEUMONIAE

Streptococcus pneumoniae, prevalent in the human upper respiratory tract, causes various infections including pneumonia, often in vulnerable individuals. Its virulence is linked to its polysaccharide capsule, interfering with phagocytosis. Early detection and treatment with appropriate antibiotics and preventive vaccination are vital, especially for high-risk groups like the elderly and immunocompromised individuals.

SHIGELLA DYSENTERIAE

Shigella dysenteriae is a Gram-negative, non-motile bacterium causing bacillary dysentery. It’s transmitted primarily through the fecal-oral route, requiring a low dose to initiate infection. Symptoms include bloody diarrhea and abdominal cramps. Diagnosis involves stool cultures, and treatment may include antibiotics for severe cases. Prevention focuses on hygiene and clean water.

TREPONEMA PALLIDUM

Treponema pallidum, a Gram-negative spirochaete, causes syphilis, a contagious STD spread through direct contact, including mother-to-child transmission. The disease progresses through primary, secondary, and tertiary stages without treatment, potentially causing severe complications. Laboratory diagnosis relies on serological tests, as the bacterium cannot be cultured in vitro. Prevention includes safe sexual practices and treating infected individuals.

Helicobacter pylori

Helicobacter pylori is a spiral-shaped bacterium causing peptic and gastric ulcers, linked to stomach cancer. It survives stomach acidity by producing urease, creating an alkaline environment. Spread via fecal-oral route, it induces inflammation in the gastric mucosa. Diagnosis involves invasive and non-invasive tests, treatment includes antibiotics and protein-pump inhibitors. Prevention focuses on hygiene.

SALMONELLA (S. TYPHI)

Salmonella Typhi, a Gram-negative rod, causes typhoid fever in humans, transmitted through contaminated food and water. Non-typhoid strains, like S. Typhimurium, cause gastrointestinal infections. Infections primarily spread via the fecal-oral route, and effective prevention includes good hygiene, proper food handling, and clean water. Treatment involves antibiotics and hydration.

RICKETTSIA PROWAZEKII

Rickettsia prowazekii is an obligate intracellular parasite causing epidemic typhus, primarily transmitted via lice bites. Symptoms include vasculitis, thrombosis, and systemic infections. Diagnosis involves serological tests and cell culture. Treatment includes chloramphenicol and tetracyclines; prevention focuses on vector control and hygiene. RMSF and Q fever are related rickettsial diseases.

STREPTOCOCCUS PYOGENES

Streptococcus pyogenes, a Group A Streptococcus, is a Gram-positive bacterium causing pharyngitis and various streptococcal diseases like scarlet fever, cellulitis, and necrotizing fasciitis. It produces numerous virulence factors including streptolysins and exotoxins. Diagnosis involves cultural, microscopic, and serological tests. Treatment includes antibiotics like penicillin, and no vaccines exist currently.

STAPHYLOCOCCUS AUREUS

Staphylococcus aureus, a Gram-positive bacterium, is often found in the nose and skin of humans. It causes various infections including pneumonia, gastroenteritis, and toxic shock syndrome, aided by its production of toxins and enzymes. Resistant strains like MRSA are prevalent. Prevention relies on hygiene practices, as vaccines are unavailable.

Features of probiotics & reported modes of action of probiotics

Microorganisms must meet stringent criteria to be used as probiotics, including being non-pathogenic, non-toxic, and able to survive stomach acid and pancreatic secretions. Probiotics confer health benefits such as enhancing the immune system, producing vitamins, preventing GI infections, and aiding in lactose digestion, potentially treating conditions like IBS and eczema.

Monkeypox (Mpox) infection

Mpox, caused by the monkeypox virus, is a viral infection with symptoms like rash, fever, and swollen lymph nodes. Transmitted through contact with infected individuals, animals, or materials, it can be severe, especially for immunocompromised individuals. Preventive measures include vaccination and avoiding physical contact. Diagnosis involves PCR testing, and treatment includes supportive care.