BackgroundBloodstream infections (BSI) are life-threatening emergencies. Identification of the common pathogens and their susceptibility patterns is necessary for timely empirical intervention.MethodsWe conducted a 4-year retrospective analysis of blood cultures from all patients excluding neonates at the Korle-Bu Teaching hospital, Ghana, from January 2010 through December 2013. Laboratory report data were used to determine BSI, blood culture contamination, pathogen profile, and antimicrobial resistance patterns.ResultsOverall, 3633 (23.16 %) out of 15,683 blood cultures were positive for various organisms. Pathogen-positive cultures accounted for 1451 (9.3 %, 95 % CI 8.5–9.8 %). Infants recorded the highest true blood culture positivity (20.9 %, n = 226/1083), followed by the elderly (13.3 %, n = 80/601), children (8.9 %, n = 708/8000) and adults (7.2 %, n = 437/6000) (p = 0.001 for Marascuilo’s post hoc). Overall occurrence of BSI declined with increasing age-group (p = 0.001) but the type of isolates did not vary with age except for Citrobacter, Escherichia coli, Klebsiella, Salmonella, and Enterococcus species. Gram negative bacteria predominated in our study (59.8 %, n = 867/1451), but the commonest bacterial isolate was Staphylococcus aureus (21.9 %, n = 318/1451)—and this trend run through the various age-groups. From 2010 to 2013, we observed a significant trend of yearly increase in the frequency of BSI caused by cephalosporin-resistant enterobacteria (Chi square for trend, p = 0.001). Meropenem maintained high susceptibility among all Gram-negative organisms ranging from 96 to 100 %. Among Staphylococcus aureus, susceptibility to cloxacillin was 76.6 %.ConclusionOur study shows a significantly high blood culture positivity in infants as compared to children, adults and the elderly. There was a preponderance of S. aureus and Gram-negative bacteria across all age-groups. Meropenem was the most active antibiotic for Gram-negative bacteria. Cloxacillin remains a very useful anti-staphylococcal agent.Electronic supplementary materialThe online version of this article (doi:10.1186/s12941-016-0163-z) contains supplementary material, which is available to authorized users.

BackgroundAs part of malaria characterization study in the South-Tongu district of Ghana, the current study was conducted to explore relationships between malaria, schistosomiasis, soil transmitted helminths and malnutrition in riparian community settings that had hitherto encountered episodes of mass deworming exercises.MethodsSchool-age children were enrolled in a cross-sectional study from April through July 2012. Stool and urine samples were examined respectively for helminths and Schistosoma haematobium. Blood samples were analyzed for malaria parasites and haemoglobin (Hb) concentrations, respectively. Anthropometric indices were measured. Relationships were determined using generalized linear models.ResultsThe results show low numbers of asymptomatic Plasmodium falciparum (9.2 %, n = 37/404) and S. haematobium (2.5 %, n = 10/404) infections. The associations between significance terms in the multivariate analysis for P. falciparum infections were further assessed to test the significance of the product terms directly i.e., age in years [adjusted odds ratio (AOR), 3.1; 95 % confidence interval (CI) 1.1–5.6], Hb concentration (AOR = 0.71; 95 % CI 0.42–2.3), and stunted malnutrition (AOR, 8.72; 95 % CI 4.8–25.1). The P. falciparum-associated decrease in mean Hb concentration was 2.82 g/dl (95 % CI 1.63–4.1 g/dl; P = 0.001) in stunted children, and 0.75 g/dl (95 % CI 1.59–0.085 g/dl; P = 0.076) in the non-stunted cohort. The anaemia-associated decrease in mean parasitaemia in stunted children was 3500 parasites/µl of blood (95 % CI 262.46–6737.54 parasites/µl of blood; P = 0.036), and in non-stunted children 2127 parasites/µl of blood (95 % CI −0.27 to 4.53; P = 0.085). Stunted malnutrition was the strongest predictor of S. haematobium infection (AOR = 11; 95 % CI 3.1–33.6) but significant associations as described for P. falciparum infections were absent. The population attributable risk of anaemia due to P. falciparum was 6.3 % (95 % CI 2.5–9.3), 0.9 % (95 % CI 0.4–2.3) for S. haematobium, and 12.5 % (95 % CI 9.11–19.52) for stunted malnutrition.ConclusionPlasmodium falciparum, S. haematobium, intestinal helminths and their co-infections were uncommon in our school-age children. Stunting exacerbated the extent to which malaria was associated with loss in Hb concentration.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-016-2025-3) contains supplementary material, which is available to authorized users.

Animal African trypanosomiasis (AAT) is a severe, wasting disease of domestic livestock and diverse wildlife species. The disease in cattle kills millions of animals each year and inflicts a major economic cost on agriculture in sub-Saharan Africa. Cattle AAT is caused predominantly by the protozoan parasites Trypanosoma congolense and T. vivax, but laboratory research on the pathogenic stages of these organisms is severely inhibited by difficulties in making even minor genetic modifications. As a result, many of the important basic questions about the biology of these parasites cannot be addressed. Here we demonstrate that an in vitro culture of the T. congolense genomic reference strain can be modified directly in the bloodstream form reliably and at high efficiency. We describe a parental single marker line that expresses T. congolense-optimized T7 RNA polymerase and Tet repressor and show that minichromosome loci can be used as sites for stable, regulatable transgene expression with low background in non-induced cells. Using these tools, we describe organism-specific constructs for inducible RNA-interference (RNAi) and demonstrate knockdown of multiple essential and non-essential genes. We also show that a minichromosomal site can be exploited to create a stable bloodstream-form line that robustly provides >40,000 independent stable clones per transfection–enabling the production of high-complexity libraries of genome-scale. Finally, we show that modified forms of T. congolense are still infectious, create stable high-bioluminescence lines that can be used in models of AAT, and follow the course of infections in mice by in vivo imaging. These experiments establish a base set of tools to change T. congolense from a technically challenging organism to a routine model for functional genetics and allow us to begin to address some of the fundamental questions about the biology of this important parasite.

BackgroundThis study was designed to investigate whether household cockroaches harbor cephalosporin-resistant enterobacteria that share resistance determinants with human inhabitants. From February through July 2016, whole cockroach homogenates and human fecal samples from 100 households were cultured for cephalosporin-resistant enterobacteria (CRe). The CRe were examined for plasmid-mediated AmpC, ESBL, and carbapenemase genes; antibiotic susceptibility patterns; and conjugative transfer of antibiotic resistance mechanisms. Clonal associations between CRe were determined by multi-locus sequence typing (MLST).ResultsTwenty CRe were recovered from whole cockroach homogenates from 15 households. The prevalence of households with cockroaches that harbored CRe, AmpC- (based on phenotype, with no identifiable blaAmpC genes), ESBL-, and carbapenemase-producers were 15, 4, 5%(2 blaCTX-M-15/TEM-1; 1 blaCTX-M-15/TEM-4; 1 blaTEM-24; 1 blaSHV-4) and 3%(2 blaNDM-1 genes and 1 blaOXA-48 gene), respectively. Overall, 20 CRe were recovered from 61 fecal samples of inhabitants from all 15 households that had cockroach samples positive for CRe. Of these, 5CRe (1 per household) were positive for ESBLs (blaTEM-24, blaTEM-14, blaCTX-M-15/TEM-4, blaSHV-3, blaCTX-M-15/TEM-1) and none carried AmpCs or carbapenemases. From 4% of households, the pair of cockroach and human CRe shared the same sequence type (ST), clonal complex (CC), antibiogram, and conjugable bla gene sequence (house 34, E. coli ST9/CC20-blaTEM-4; house 37, E. coli ST44/CC10-blaCTX-15/TEM-4; house 41, E. coli ST443/CC205-blaCTX-15/TEM-1; house 49, K. pneumoniae ST231/CC131-blaSHV-13).ConclusionThe findings provide evidence that household cockroaches may carry CTX-M-15-, OXA-48- and NDM-1-producers, and share clonal relationship and beta-lactam resistance determinants with humans.