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Low levels of vitamin D in maternal and cord blood have been associated with neonatal sepsis. This study assessed the association of vitamin D metabolites (25(OH)D, 3-epi-25(OH)D 3 , and 24,25(OH) 2 D 3 ) levels in maternal and cord blood with newborn sepsis evaluation in Nigerian mother-infant dyads. Maternal and cord blood from 534 mothers and 536 newborns were processed using liquid chromatography-tandem mass spectrometry. Spearman correlation was used to compare continuous variables, Mann-Whitney for dichotomous variables, and Kruskal-Wallis for two or more groups. High cord percent 3-epi-25(OH)D 3 levels were positively associated with newborn evaluation for sepsis ( p = 0.036), while maternal and cord 25(OH)D and 24,25(OH) 2 D 3 levels were not. Being employed was positively associated with maternal and newborn 3-epi-25(OH)D 3 concentrations ( p = 0.007 and p = 0.005, respectively). The maternal 3-epi-25(OH)D 3 and percent 3-epi-25(OH)D 3 were positively associated with vaginal delivery ( p = 0.013 and p = 0.012, respectively). Having a weight-for-age Z-score ≤ -2 was positively associated with newborn percent 3-epi-25(OH)D 3 levels ( p = 0.004), while a weight-for-length Z-score ≤ -3 was positively associated with maternal and newborn percent 3-epi-25(OH)D 3 levels ( p = 0.044 and p = 0.022, respectively). Our study highlights the need to further investigate the biological role of 3-epi-25(OH)D 3 and its clinical significance in fetal growth and newborn outcome.

Streptococcus pneumoniae ( pneumococcus ) is a leading vaccine-preventable cause of childhood invasive disease. Nigeria has the second highest pneumococcal disease burden globally, with an estimated ~49 000 child deaths caused by pneumococcal infections each year. Ten-valent pneumococcal conjugate vaccine (GSK; PCV10) was introduced in December 2014 in a phased approach. However, few studies have characterized the disease-causing pneumococci from Nigeria. This study assessed the prevalence of serotypes, antibiotic susceptibility and genomic lineages using whole genome sequencing and identified lineages that could potentially escape PCV10 (GSK). We also investigated the potential differences in pneumococcal lineage features between children with and without sickle cell disease. A collection of 192 disease-causing pneumococcal isolates was obtained from Kano ( n =189) and Abuja ( n =3) states, Nigeria, between 1 January 2014 and 31 May 2018. The majority (99 %, 190/192) of specimens were recovered from children aged 5 years or under. Among them, 37 children had confirmed or traits of sickle cell disease. Our findings identified 25 serotypes expressed by 43 Global Pneumococcal Sequence Clusters (GPSCs) and 85 sequence types (STs). The most common serotypes were 14 (18 %, n =35), 6B (16 %, n =31), 1 (9 %, n =17), 5 (9 %, n =17) and 6A (9 %, n =17); all except serotype 6A are included in PCV10 (GSK). PCV10 (SII; PNEUMOSIL) and PCV13 formulations include serotypes 6A and 19A which would increase the overall coverage from 67 % by PCV10 (GSK) to 78 and 82 %, respectively. The pneumococcal lineages were a mix of globally spreading and unique local lineages. Following the use of PCV10 (GSK), GPSC5 expressing serotype 6A, GPSC10 (19A), GPSC26 (12F and 46) and GPSC627 (9L) are non-vaccine type lineages that could persist and potentially expand under vaccine-selective pressure. Approximately half (52 %, 99/192) of the pneumococcal isolates were resistant to the first-line antibiotic penicillin and 44 % (85/192) were multidrug-resistant. Erythromycin resistance was very low (2 %, 3/192). There was no significant difference in clinical manifestation, serotype prevalence or antibiotic resistance between children with and without traits of or confirmed sickle cell disease. In summary, our findings show that a high percentage of the pneumococcal disease were caused by the serotypes that are covered by currently available vaccines. Given the low prevalence of resistance, macrolide antibiotics, such as erythromycin, should be considered as an option to treat pneumococcal disease in Nigeria. However, appropriate use of macrolide antibiotics should be vigilantly monitored to prevent the potential increase in macrolide resistance.

Infections caused by multi-drug resistant Enterobacterales (MDR-E) are difficult to treat and cause significant mortality, especially in developing countries. This study characterized the phenotypic and genotypic profiles of 49 randomly selected beta-lactam resistant MDR-E previously isolated from patients being managed in hospitals in Nigeria using whole genome sequencing. The study isolates exhibited 85.5% resistance to 3rd generation cephalosporins and 65.3% resistance to carbapenems. The bla TEM-1B (29, 59.2%) , bla CTX-M-15 (38, 77.6%) , and bla NDM-1 (17, 51.5%) were the most common penicillinase, ESBL, and carbapenem resistant genes across isolates, respectively. Seventeen (45%) of bla CTX-M-15 was carried on the insertion sequence ISEc9 while bla NDM-1 (11, 64.7%) were associated with ISEc33. None of the 21 plasmids detected were associated with β-lactamase genes. Higher resistance rates were found in E. coli ST-88 (n = 2) and the high-risk ST-692 (n = 2). For Klebsiella species, the high-risk clones ST-476 (n = 8) and ST-147 (n = 3) predominated and had higher phenotypic resistance rates and higher number of AMR genes. The mechanisms and pattern of antibiotic resistance differ from patterns previously described with isolates harbouring a wide range of AMRGs. The detection of several chromosomally mediated carbapenemases in our study also represents a significant finding that warrants further investigation to better understand its' implications for clinical practice and public health. The selected MDR-Es were found to be pan-susceptible to tigecycline and had very low resistance to fosfomycin, suggesting a potential for these as empiric treatments. A surveillance approach incorporating both conventional laboratory techniques and modern molecular techniques is essential for the comprehensive characterization of the emergence and dissemination of antimicrobial resistance in Enterobacterales infections within Nigeria., (© 2023. The Author(s).)

Objectives: Bacteremia due to invasive Salmonella enterica has been reported earlier in children in Nigeria. This study aimed to detect the virulence and antibiotic resistance genes of invasive Salmonella enterica from children with bacteremia in north-central Nigeria., Method: From June 2015 to June 2018, 4163 blood cultures yielded 83 Salmonella isolates. This is a secondary cross-sectional analysis of the Salmonella isolates. The Salmonella enterica were isolated and identified using standard bacteriology protocol. Biochemical identifications of the Salmonella enterica were made by Phoenix MD 50 identification system. Further identification and confirmation were done with polyvalent antisera O and inv A gene. Antimicrobial susceptibility testing was done following clinical and laboratory standard institute guidelines. Resistant genes and virulence genes were determined using a real-time polymerase chain reaction., Result: Salmonella typhi 51 (61.4%) was the most prevalent serovar, followed by Salmonella species 13 (15.7%), choleraesuis 8 (9.6%), enteritidis 6 (7.2%), and typhimurium 5 (6.1%). Fifty-one (61.4%) of 83 Salmonella enterica were typhoidal, while 32 (38.6%) were not. Sixty-five (78.3%) of the 83 Salmonella enterica isolates were resistant to ampicillin and trimethoprim-sulfamethoxazole, followed by chloramphenicol 39 (46.7%), tetracycline 41 (41.4%), piperacillin 33 (33.9%), amoxicillin-clavulanate, and streptomycin 21 (25.3%), while cephalothin was 19 (22.9%). Thirty-nine (46.9%) of the 83 Salmonella enterica isolates were multi-drug resistant, and none were extensive drug resistant or pan-drug resistant. A bla TEM 42 (50.6%), flo R 32 (38.6%), qnr A 24 (28.9%), tet B 20 (20.1%), tet A 10 (10.0%), and tet G 5 (6.0%) were the antibiotic resistance genes detected. There were perfect agreement between phenotypic and genotypic detection of antimicrobial resistance in tetracycline, ciprofloxacin, and chloramphenicol, while beta-lactam showed κ = 0.60 agreement. All of the Salmonella enterica isolates had the virulence genes inv A, sop B, mgt C, and sip 4D, while 33 (39.8%), 45 (51.8%), and 2 (2.4%) had ssa Q, spv C, and ljs GI-1, respectively., Conclusion: Our findings showed multi-drug resistant Salmonella enterica in children with bacteremia in northern Nigeria. In addition, significant virulence and antimicrobial resistance genes were found in invasive Salmonella enterica in northern Nigeria. Thus, our study emphasizes the need to monitor antimicrobial resistance in Salmonella enterica from invasive sources in Nigeria and supports antibiotic prudence., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Aim: This study aimed to investigate the isolation rate, antibiotic resistance and virulence genes of Salmonella enterica serovar from two commercial farms in Nigeria., Methods and Results: Salmonella isolation was performed according to the United States Food and Drug Agency (USFDA) method. Serotyping, antimicrobial susceptibility testing, detection of resistance and virulence genes were done using the Kauffman-White Scheme, disc diffusion, minimum inhibitory concentration and real-time polymerase chain reaction techniques. Salmonella serovars were isolated from only farm A at 22/50 (44.0%) while none were isolated from farm B. Salmonella Typhi, 9 (40.9%); Salmonella Typhimurium, 2 (9.1%), Salmonella Enteritidis, 2 (9.1%), Salmonella Pullorum, 1 (4.5%), Salmonella Kentucky, 4 (18.2%) were identified while 4 (18.2%) were untypable. Sixteen isolates (72.7%) showed multiple drug resistance and 17 different resistance profile types with AMP-CHL-TRM-SXT as the most prevalent pattern. Resistance genes (blaTEM, 12/22 (54.5%) and virulence genes (InvA, sopB, mgtC and spi4D, 22/22 (100.0%), ssaQ, 16/22 (72.7%) and spvC, 13/22 (59.1%) were found, while blaSHV, blaCTX-M, floR, tetA, tetB, tetG and LJSGI-1 genes were absent., Conclusion: Pathogenic Salmonella were isolated from the chicken droppings in this study. Most of these strains were resistant to antibiotics and possessed characteristics of virulence., Significance and Impact of the Study: Chicken droppings from this study area contained pathogenic strains of Salmonella and a rare occurrence of Salmonella Typhi. The study revealed that the environment and the food chain could be at risk of contamination of highly virulent and antimicrobial-resistant strains of Salmonella. These could affect the profitability of the poultry industry and food consumption. There is a need for caution in indiscriminate disposal of poultry waste and the use of uncomposted chicken droppings in soil amendment., (© 2022 Society for Applied Microbiology.)