Use of probiotics to reduce infections and death and prevent colonization with extended-spectrum beta-lactamase (ESBL)-producing bacteria among newborn infants in Tanzania (ProRIDE Trial): study protocol for a randomized controlled clinical trial.

BACKGROUND: Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) has emerged as an urgent global health threat and is by the World Health Organization ranked as priority 1 among pathogens in need of new treatment. Studies have shown high mortality in Tanzanian children with ESBL-E infections. Gut colonization of ESBL-E, which is a potential risk factor of ESBL-E infections, is reported to be very high among children in Tanzania. Probiotics may potentially reduce gut colonization of multidrug-resistant bacteria. However, there is limited data on whether probiotics may reduce ESBL-E carriage in infants. The ProRIDE Trial aims to evaluate whether the use of probiotics can reduce morbidity and mortality among infants in Haydom, Tanzania, and whether this effect is associated with a reduction in ESBL-E colonization and/or infections. METHODS/DESIGN: This large randomized double-blinded placebo-controlled trial aims to recruit 2000 newborn infants at Haydom Lutheran Hospital and the surrounding area in the period of November 2020 to November 2021. Participants will be enrolled from days 0 to 3 after birth and randomized to receive probiotics or placebo for 4 weeks. Participants will be followed-up for 6 months, during which three visits will be made to collect clinical and demographic information, as well as rectal swabs and fecal samples which will be subjected to laboratory analysis. The primary composite outcome is the prevalence of death and/or hospitalization at 6 months of age. DISCUSSION: As the use of probiotics may give a more favorable gut composition, and thereby improve health and reduce morbidity and mortality, the results may have implications for future therapy guidelines in Africa and internationally. TRIAL REGISTRATION: ClinicalTrials.gov NCT04172012. Registered on November 21, 2019.

High Prevalence of Fecal Carriage of Extended Spectrum ß-Lactamase-Producing Enterobacteriaceae Among Newly HIV-Diagnosed Adults in a Community Setting in Tanzania.

Colonization in HIV-infected populations with extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) is particularly worrisome in low-income settings. This study describes the prevalence of ESBL-PE carriage and associated risk factors among newly HIV-diagnosed adults in a community setting in Tanzania. A total of 595 newly diagnosed HIV adults with a median age of 35 years with interquartile range (IQR) 29-42 years and a median CD4 count of 492 cells/µL (IQR 390-666 cells/µL) were recruited. Among these, 194/595 (32.6%, 95% confidence interval [CI] 28.9-36.6) were ESBL-PE carriers. Participants with low CD4 count (<350 cells/µL) had significantly higher prevalence of ESBL-PE carriage compared with those with CD4 count ≥350 cells/µL (26/58, 44.8%, vs. 168/537, 31.3%, p = 0.04). Antibiotic use in last 4 weeks (odds ratio [OR] 1.55, 95% CI 1.08-2.22, p = 0.02) and CD4 count ≥350 cells/µL (OR 1.78, 95% CI 1.03-3.09, p = 0.04) were independent risk factors for fecal carriage of ESBL-PE. In total, 244 isolates of ESBL-PE were isolated from 194 participants. Of these, 238/244 (97.5%) harbored blaCTX-M genes, with blaCTX-M-15 being predominant (219/238 (92%), followed by blaCTX-M-27 (9/238 (3.8%), blaCTX-M-14 (8/238 (3.4%), blaCTX-M-55 (1/238), and blaCTX-M 211/3 (1/238). blaSHV-2a genes were detected in four isolates, whereas the blaSHV-12 gene was detected in one isolate. Phenotypic carbapenemase-producing Enterobacteriaceae was detected in one HIV-positive person with CD4 count 132 cells/µL. In conclusion prevalence of ESBL-PE carriage is high among newly diagnosed HIV adults in Dar es Salaam, and is significantly associated antibiotic use and low CD4 count.

Horizontal Plasmid Transfer among Klebsiella pneumoniae Isolates Is the Key Factor for Dissemination of Extended-Spectrum ß-Lactamases among Children in Tanzania.

Increased knowledge about the role of horizontal gene transfer is key to improve our understanding of the spread of antimicrobial resistance (AMR) in human populations. We therefore studied the dissemination of the blaCTX-M-15 extended-spectrum-ß-lactamase (ESBL) gene in Klebsiella pneumoniae isolates obtained from stool samples from hospitalized children and healthy controls below 2 years of age in Dar es Salaam, Tanzania, from August 2010 to July 2011. We performed Illumina whole-genome sequencing (WGS) to characterize resistance genes, multilocus sequence type (MLST), plasmid incompatibility group (Inc), and plasmid MLST of 128 isolates of K. pneumoniae with blaCTX-M-15 recovered from both healthy and hospitalized children. We assessed the phylogenetic relationship using single nucleotide polymorphism (SNP)-based analysis and resolved the sequences of five reference plasmids by Oxford Nanopore technology to investigate plasmid dissemination. The WGS analyses revealed the presence of a blaCTX-M-15-positive IncFIIK5/IncR plasmid with a highly conserved backbone in 70% (90/128) of the isolates. This plasmid, harboring genes encoding resistance to most ß-lactams, aminoglycosides, trimethoprim-sulfamethoxazole, and chloramphenicol, was present in phylogenetically very diverse K. pneumoniae strains (48 different MLSTs) carried by both hospitalized and healthy children. Our data strongly suggest widespread horizontal transfer of this ESBL-carrying plasmid both in hospitals and in the general population.IMPORTANCE Horizontal spread of plasmids carrying multiple resistance genes is considered an important mechanism behind the global health problem caused by multidrug-resistant bacteria. Nevertheless, knowledge about spread of plasmids in a community is limited. Our detailed molecular analyses of K. pneumoniae isolated from hospitalized and healthy children in Tanzania disclosed an epidemic spread of a resistance plasmid. In this study population, we revealed horizontal plasmid transfer among K. pneumoniae as the key factor for dissemination of ESBLs. Traditional outbreak investigation and surveillance focus on the spread of bacterial clones, and short-read sequencing can result in erroneous plasmid composition. Our approach using long-read sequencing reveals horizontal gene transfer of antimicrobial resistance, and therefore has a potential impact on outbreak investigations and approaches to limit spread of AMR.

Prevalence and molecular characterisation of human adenovirus in diarrhoeic children in Tanzania; a case control study.

BACKGROUND: Human adenovirus (HAdV) causes acute diarrhoea sporadically, as well as in outbreaks. Understanding the prevalence and types of HAdV in diarrhoea is important for control and preventive measures, especially in the African region where there is a high burden of diarrhoeal disease. The present study assessed the prevalence, molecular characteristics, seasonality and associated clinical features of HAdV infection Tanzanian children below two years of age with and without diarrhoea between 2010-2011. METHODS: Stool specimens, demographic and clinical information were collected in 690 cases and 545 controls. All stool samples were screened for HAdV-antigen using ELISA. Positive samples subsequently underwent real-time PCR and sequencing for molecular typing. RESULTS: HAdV was detected in 37 children, corresponding to a prevalence of 3.5% (24/690) in diarrhoeic and 2.4% (13/545) in non-diarrhoeic children (P > 0.05). Among HAdV-infected children, the median age was significantly lower in diarrhoeic than in non-diarrhoeic children (10 vs. 14 months, P˂0.001). More than half of HAdV infected (54.2%) were dehydrated as compared to diarrhoeic children without HAdV (45.8%, P = 0.01). The proportion of the enteric HAdV type 40/41 in diarrhoeic and non-diarrhoeic children was (50.0%, 12/24) and (46.2%, 6/13) respectively. Other HAdV types detected were; 1, 2, 7, 18, 19 and 31. The prevalence of adenovirus was not significantly different between rainy and dry seasons. HAdV was not detected in the 33 known HIV positive children. There was no significant association between HAdV infection and gender, nutritional status of the child and parent educational level. CONCLUSION: The present study provides further evidence of the contribution of adenovirus in causing gastroenteritis in young children, with symptomatic infection being significantly more prevalent in children below one year. We found similar prevalence of adenovirus in non-diarrhoeic children and in diarrhoeic children. This first report on molecular epidemiology of human adenovirus in Tanzania observed diversity of HAdV types that circulate the study setting. The study findings suggest that HAdV is not an important cause of diarrhoea in young HIV-positive children.

High nasal carriage of methicillin-resistant Staphylococcus aureus among healthy Tanzanian under-5 children.

This study aimed to determine the prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) carriage, risk factors of colonization and antimicrobial susceptibility patterns of S. aureus strains. The study was conducted at the Muhimbili National Hospital in Dar es Salaam, Tanzania. Nasal swabs were obtained from children and S. aureus was isolated and identified using conventional culture methods. MRSA was screened and confirmed using the cefoxitin disk and multiplex real-time polymerase chain reaction, respectively. Antibiotic susceptibility was performed using the Kirby-Bauer disk diffusion method. MRSA isolates were further characterized by pulsed field gel electrophoresis (PFGE) profiling. Of 285 children included in the study, S. aureus was detected in 114 (40%). Of the 114 isolates, 12 (10.5%) were MRSA. PFGE results showed that these MRSA isolates are epidemiologically unrelated. Resistance of all S. aureus to trimethoprim-sulfamethoxazole, tetracycline, gentamicin, and ciprofloxacin was 65.8%, 23.7%, 27.2%, and 4.4%, respectively. No resistance to vancomycin was found. The prevalence of inducible clindamycin resistance, constitutive clindamycin resistance, MS phenotype (resistance to erythromycin alone), and multidrug resistance was 16.7%, 1.8%, 14.0%, and 16.8%, respectively. None of the risk factors examined was found to be significant. This is the first report of S. aureus and nasal carriage of MRSA and a high rate of S. aureus carriage was found in Tanzanian under-5 children. The study findings support the need for proper health education and effective infection control measures for healthcare workers.