Microbiology and Parasitology

Pangenome analysis of Tanzanian clinical Klebsiella pneumoniae reveals pandemic clones with high genome plasticity and versatile mobilome, virulome, and resistome profiles

2026-06-10T12:43:19Z

Pangenome analysis of Tanzanian clinical Klebsiella pneumoniae reveals pandemic clones with high genome plasticity and versatile mobilome, virulome, and resistome profiles Bahati, Samweli; Maghembe, Reuben Klebsiella pneumoniae is a rapidly evolving pathogen with a diverse pangenome whose mobilome and resistome remain elusive. Here, we aimed to delineate the pangenome of 198 isolates from Tanzanian regions. Raw Illumina reads retrieved from public repositories were assembled and analyzed using multilocus sequence typing, core-genome single nucleotide polymorphism (SNP)-based phylogeny, and capsular polysaccharide (K-locus) and lipopolysaccharide O-antigen (O-locus) typing. A total of 184 isolates were classified as Klebsiella pneumoniae sensu stricto, while 14 belonged to other species within the Klebsiella pneumoniae complex. We identified 90 sequence types (STs), including global high-risk ST45, ST39, ST336, ST14, ST1552, and ST17. KL24 and KL25 were the most common K-loci, while OL2α.1 and OL2α.2 were dominant O-loci. Pangenome analysis revealed 30,992 gene families, distributed as persistent (13.6%), shell (11.2%), and cloud (75.2%) genes, suggesting an open pangenome structure. Core-genome SNP-based phylogeny confirmed clonal expansion and lineage clustering. Virulence profiling showed yersiniabactin in 44% of isolates. Most genomes carried key fimbrial and iron uptake genes. Resistome analysis revealed near-universal presence of bla_CTX-M-15, oqxA/B, fosA6, sul2, and marA. Plasmid typing identified IncF-type (76%) and Col-type (54%) plasmids, while over 120 mobile genetic elements were detected, whose frequencies were on a huge spectrum of insertion sequences (e.g., IS5075 and MITEYpe1) and transposons (e.g., Tn5403 and Tn6082). Conclusively, Tanzanian K. pneumoniae strains exhibit extensive genomic plasticity, high-risk lineages, and a versatile mobilome, calling for national genomic surveillance to inform intervention strategies. IMPORTANCE The Klebsiella pneumoniae complex comprises a diverse group of bacterial pathogens adapted to thrive over a wide range of environments. Isolates from clinical and environmental samples are implicated in nosocomial infections and multidrug resistance, with similar genome structures and inherent genes. Our study presents the first pangenome report underlying genomic plasticity of K. pneumoniae isolates from Tanzanian clinical specimens, demonstrating versatile clones, mobilome, and resistome profiles. Combining these profiles with the versatility of K and O structures, our study emphasizes the need for comprehensive multidisciplinary surveillance studies to optimize therapeutic and vaccine development.

Factors Influencing Dietary Diversity and Nutritional Status among Adolescent Pregnant Women in South-Eastern Tanzania: a Hospital-Based Cross-Sectional Study

2026-06-10T11:16:56Z

Factors Influencing Dietary Diversity and Nutritional Status among Adolescent Pregnant Women in South-Eastern Tanzania: a Hospital-Based Cross-Sectional Study Muga, Miriam; Katusi, Godfrey Adolescent pregnancy has become a global health concern in recent years, with maintaining dietary diversity being essential to ensure the health of both the mother and fetus. This study aimed to understand the dietary diversity and nutritional status among pregnant adolescents attending antenatal clinic and identify the factors influencing these outcomes. A hospital-based crosssectional study was done at St Francis Regional Referral Hospital in Ifakara, Tanzania. A total of 131 adolescent pregnant women consented to participate. Data was obtained using a questionnaire and 24-hour dietary recall. The study revealed that 93.1% (n=122) of adolescent pregnant women met the minimum dietary diversity score based on a 24-hour recall period. Similar proportions were observed for the age group but vary significantly with the number of children born (p< 0.001), marital status (p = 0.032) and education level (p< 0.001). Additionally, 93.9% (n=123) of adolescent pregnant women had a normal Mid-Upper Arm Circumference (MUAC) and 6.1% (n=8) were undernourished. Similar proportions were observed across age, number of children born, marital status, education status, and occupation. Most adolescent pregnant women in this study achieved adequate dietary diversity. However, socio-demographic factors such as age, marital status, and education, as well as challenges like illness and loss of appetite, influenced their dietary diversity and overall nutritional status. Future research should adopt a community-based longitudinal approach to better understand these factors and provide a more comprehensive understanding of the dietary patterns of adolescent pregnant women.

A power analysis framework to aid the design of robust semi‑field vector control experiments

2026-06-10T09:28:35Z

A power analysis framework to aid the design of robust semi‑field vector control experiments Kipingu, Andrea; Lwetoijera, Dickson; Ng’habi, Kija; Kiware, Samson; Viana, Mafalda; Johnson, Paul Background Semi-field experiments are an efficient way of assessing the impacts of potential new vector control tools (VCTs) before field trials. However, their design is critically important to ensure their results are unbiased and informative. An essential element of the design of semi-field experiments is power analysis, which empowers researchers to ensure that only designs with adequate statistical power are adopted. In this study, a methodology was developed, and its use was demonstrated in a tutorial, to determine the required number of semi-field chambers, sampling frequency and the number of mosquitoes required to achieve sufficient power for evaluating the impact of a single VCT or two in combination. Methods By analysing data simulated from a generalized linear mixed-effects model, power was estimated for various experimental designs, including short- (24 h) vs. long-term (3 months) experiments and single vs. combined application of interventions (e.g., insecticide-treated nets combined with pyriproxyfen autodissemination). Results Although power increased with increasing number of chambers, sampling frequency and the number of mosquitoes, the number of chambers and variance between chambers were the dominant factors determining power relative to all other design choices. High variance between chambers decreased power, highlighting the importance of making conditions similar among chambers, by reducing variation if possible and by rotating variables if not. As compared to a single intervention, an additional intervention required an increase in the number of chambers, while short and long experiments were similar in terms of key aspects such as the number of chambers per treatment. Conclusion Determining the most efficient experimental design for a semi-field experiment will depend on a balance of design choices and resource constraints. The power analysis framework and tutorial provided here can aid in the robust design of these widely used experiments and ultimately facilitate the development of new vector control tools (VCTs).

Performance of Hb HemoCue Machine Compared to Automated Hematology Analyzer for Hemoglobin Measurements Among Adult Patients at Kilimanjaro Christian Medical Centre

2026-06-10T08:22:26Z

Performance of Hb HemoCue Machine Compared to Automated Hematology Analyzer for Hemoglobin Measurements Among Adult Patients at Kilimanjaro Christian Medical Centre Kassam, Nancy; Mwanga, Goodluck; Laizer, Zacharia; Yusuph, Elia; Maundi, Elda; Josephat, Moses; Kulaya, Neema; Laswai, Daniel; Ndossy, Goodluck; Kimaro, James; Ndaro, Arnold Background: Automated haematology analysers offer precise haemoglobin measurements, but are expensive and impractical for field, point of care, primary care and remote settings use. The portable and cost-effective Hemocue device provides an alternative. Comparing their accuracies is crucial to prevent diagnostic discrepancies and misdiagnoses. This study aimed to determine the accuracy of Hb HemoCue machine by comparing its performance to automated analyser at Kilimanjaro Christian Medical Centre (KCMC) clinical laboratory where both equipment are used. Methodology: A cross-sectional study was conducted at KCMC Clinical Laboratory among adult patients whose haemoglobin concentrations were measured from May to June 2024. Haemoglobin levels were estimated using two distinct methods: Hb HemoCue machine and automated haematology analyser. Results: Haemoglobin (Hb) concentration values obtained from the HemoCue machine and the automated analyser, had a mean difference of 0.001 g/dL (95% Cl: -0.036 to 0.038), t value of 0.062, and a p-value of .95, indicating a non-statistically significant differences between the two measurement methods. The Bland-Altman plot analysis indicated that the mean difference (bias) between the two methods was 0.0012 g/dL, and the limits of agreement ranged from -0.481 to 0.482 g/dL, suggesting that the HemoCue machine tends to slightly overestimate Hb values compared to the automated haematology analyser. The Pearson correlation coefficient for the Hb concentrations measured using HemoCue and automated analyser was 0.995, indicating a very strong positive correlation. The HemoCue demonstrated a sensitivity of 98.3%, specifity of 90.4%, positive predictive value of 95.9% and a negative predictive value of 95.9%, indicating high performance accuracy of HemoCue in diagnosing anaemia. Conclusion: The study revealed strong agreement between HemoCue and automated haematology analyser for measuring haemoglobin concentrations. Both methods demonstrated high diagnostic accuracy suitable for clinical use. Although HemoCue slightly overestimated haemoglobin, this difference was deemed insignificant. The study endorses HemoCue as a reliable tool for haemoglobin concentration measurement alongside and in lack of automated analysers.