ABSTRACT
The study focused on the extraction of free erythromycin from commercially manufactured tablets and the use of metal salts to synthesize erythromycin-metal complexes, specifically involving silver (Ag), nickel (Ni), cobalt (Co), and copper (Cu). The synthesis was confirmed through various methods, including elemental analysis, thermogravimetric analysis, Fourier-transform infrared (FTIR), and UV-visible spectroscopy. The microbiological investigation involved Salmonella typhi, Escherichia coli, Staphylococcus aureus, Bacillus cereus, Candida albicans, and Microsporum canis as test organisms. The NCCLS broth microdilution reference method was used to determine the minimum fungicidal concentration and minimum inhibitory concentration of the complexes. The synthesized complexes were highly effective against a variety of fungi and bacteria, with compound Ery-Cu having MIC as low as 1.56 mg/mL, Ery-Cu and Ery-Ni with MBCs of 6.25 mg/mL and Ery-Cu having MFC of 6.25 mg/mL. Dose-dependent inhibitory effects were found upon examination of the antimicrobial susceptibility of specific complexes (Cu, Ni, Co and Ag) at varying concentrations of 100, 50, 25 and 12.5 mm/mL. Antibiotic susceptibility testing revealed efficacy against the tested pathogens. The study suggests that the synthesis of erythromycin-metal complexes, coupled with their antibacterial effectiveness against a diverse spectrum of bacteria and fungi, as they showed promising inhibitory properties when tested against a range of test species (Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Candida albicans, and Microsporum canis), could lead to the development of innovative antibacterial agents. Molecular docking simulations were used to examine the interactions between metal complexes with proteins filamentous temperature-sensitive protein Z and lanosterol 14α-demethylase. The study highlights the need for further exploration in pharmaceutical research.
ABSTRACT
Noroviruses constitute a significant aetiology of sporadic and epidemic gastroenteritis in human hosts worldwide, especially among young children, the elderly, and immunocompromised patients. The low infectious dose of the virus, protracted shedding in faeces, and the ability to persist in the environment promote viral transmission in different socioeconomic settings. Considering the substantial disease burden across healthcare and community settings and the difficulty in controlling the disease, we review aspects related to current knowledge about norovirus biology, mechanisms driving the evolutionary trends, epidemiology and molecular diversity, pathogenic mechanism, and immunity to viral infection. Additionally, we discuss the reservoir hosts, intra-inter host dynamics, and potential eco-evolutionary significance. Finally, we review norovirus vaccines in the development pipeline and further discuss the various host and pathogen factors that may complicate vaccine development.
ABSTRACT
Gastroenteritis viruses are the leading etiologic agents of diarrhea in children worldwide. We present data from thirty-three (33) eligible studies published between 2003 and 2023 from African countries bearing the brunt of the virus-associated diarrheal mortality. Random effects meta-analysis with proportion, subgroups, and meta-regression analyses were employed. Overall, rotavirus with estimated pooled prevalence of 31.0 % (95 % CI 24.0-39.0) predominated in all primary care visits and hospitalizations, followed by norovirus, adenovirus, sapovirus, astrovirus, and aichivirus with pooled prevalence estimated at 15.0 % (95 % CI 12.0-20.0), 10 % (95 % CI 6-15), 4.0 % (95 % CI 2.0-6.0), 4 % (95 % CI 3-6), and 2.3 % (95 % CI 1-3), respectively. Predominant rotavirus genotype was G1P[8] (39 %), followed by G3P[8] (11.7 %), G9P[8] (8.7 %), and G2P[4] (7.1 %); although, unusual genotypes were also observed, including G3P[6] (2.7 %), G8P[6] (1.7 %), G1P[6] (1.5 %), G10P[8] (0.9 %), G8P[4] (0.5 %), and G4P[8] (0.4 %). The genogroup II norovirus predominated over the genogroup I-associated infections (84.6 %, 613/725 vs 14.9 %, 108/725), with the GII.4 (79.3 %) being the most prevalent circulating genotype. In conclusion, this review showed that rotavirus remains the leading driver of viral diarrhea requiring health care visits and hospitalization among under-five years children in Africa. Thus, improved rotavirus vaccination in the region and surveillance to determine the residual burden of rotavirus and the evolving trend of other enteric viruses are needed for effective control and management of cases.