Annual Records of Airborne Pollen of Poaceae in Five Areas in Lagos,Nigeria

Poaceae pollen grains are known to be highly allergenic and they are potential causes of allergic respiratory diseases. In order to investigate the incidence of airborne Poaceae, and contribute to current trends in the development of aeropalynology/allergy studies in Nigeria, five highly populated locations in Central Lagos State, Surulere, Ebute-Metta, University of Lagos, Bariga and Gbagada, were sampled. Gravimetric aerosamples were collected monthly from January 2013 to December 2014. The lowest count in 2013 was recorded in the Ebute-Metta area (179), while the highest in 2013 was recorded in Gbagada (564). In 2014, the Surulere area (282) had the lowest count while Bariga (671) had the highest. The locations have similar monthly pollen distribution pattern but different peak months. Generally, Poaceae pollen counts were lowest in the months of June and July. These are therefore the safest months for Poaceae pollen hypersensitive individuals in the study areas. Relative humidity was the most important meteorological parameter with significant correlations in Ebute-Metta and Bariga locations. Results from this work will form the basis for a forecast service required to inform and educate the general public and allergy sufferers about Poaceae pollen distribution in Lagos State.     

Countdown to 2015: Tracking Maternal and Child Health Intervention Targets Using Lot Quality Assurance Sampling in Bauchi State Nigeria

Background

Improving maternal and child health remains a top priority in Nigeria’s Bauchi State in the northeastern region where the maternal mortality ratio (MMR) and infant mortality rate (IMR) are as high as 1540 per 100,000 live births and 78 per 1,000 live births respectively. In this study, we used the framework of the continuum of maternal and child care to evaluate the impact of interventions in Bauchi State focused on improved maternal and child health, and to ascertain progress towards the achievement of Millennium Development Goals (MDGs) 4 and 5.

Methods

At baseline (2012) and then at follow-up (2013), we randomly sampled 340 households from 19 random locations in each of the 20 Local Government Areas (LGA) of Bauchi State in Northern Nigeria, using the Lot Quality Assurance Sampling (LQAS) technique. Women residents in the households were interviewed about their own health and that of their children. Estimated LGA coverage of maternal and child health indicators were aggregated across the State. These values were then compared to the national figures, and the differences from 2012 to 2014 were calculated.

Results

For several of the indicators, a modest improvement from baseline was found. However, the indicators in the continuum of care neither reached the national average nor attained the 90% globally recommended coverage level. The majority of the LGA surveyed were classifiable as high priority, thus requiring intensified efforts and programmatic scale up.

Conclusions

Intensive scale-up of programs and interventions is needed in Bauchi State, Northern Nigeria, to accelerate, consolidate and sustain the modest but significant achievements in the continuum of care, if MDGs 4 and 5 are to be achieved by the end of 2015. The intentional focus of LGAs as the unit of intervention ought to be considered a condition precedent for future investments. Priority should be given to the re-allocating resources to program areas and regions where coverage has been low. Finally, systematic considerations need to be given to the design of strategies that address the demand for health services.     

High resolution assembly and characterization of genomes of Canadian isolates of Salmonella Enteritidis

Background

There is a need to characterize genomes of the foodborne pathogen, Salmonella enterica serovar Enteritidis (SE) and identify genetic information that could be ultimately deployed for differentiating strains of the organism, a need that is yet to be addressed mainly because of the high degree of clonality of the organism. In an effort to achieve the first characterization of the genomes of SE of Canadian origin, we carried out massively parallel sequencing of the nucleotide sequence of 11 SE isolates obtained from poultry production environments (n = 9), a clam and a chicken, assembled finished genomes and investigated diversity of the SE genome.

Results

The median genome size was 4,678,683 bp. A total of 4,833 chromosomal genes defined the pan genome of our field SE isolates consisting of 4,600 genes present in all the genomes, i.e., core genome, and 233 genes absent in at least one genome (accessory genome). Genome diversity was demonstrable by the presence of 1,360 loci showing single nucleotide polymorphism (SNP) in the core genome which was used to portray the genetic distances by means of a phylogenetic tree for the SE isolates. The accessory genome consisted mostly of previously identified SE prophage sequences as well as two, apparently full- sized, novel prophages namely a 28 kb sequence provisionally designated as SE-OLF-10058 (3) prophage and a 43 kb sequence provisionally designated as SE-OLF-10012 prophage.

Conclusions

The number of SNPs identified in the relatively large core genome of SE is a reflection of substantial diversity that could be exploited for strain differentiation as shown by the development of an informative phylogenetic tree. Prophage sequences can also be exploited for SE strain differentiation and lineage tracking. This work has laid the ground work for further studies to develop a readily adoptable laboratory test for the subtyping of SE.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-713) contains supplementary material, which is available to authorized users.     

Subtyping of a Large Collection of Historical Listeria monocytogenes Strains from Ontario,Canada, by an Improved Multilocus Variable-Number Tandem-Repeat Analysis (MLVA)

Listeria monocytogenes is responsible for severe and often fatal food-borne infections in humans. A collection of 2,421 L. monocytogenes isolates originating from Ontario''s food chain between 1993 and 2010, along with Ontario clinical isolates collected from 2004 to 2010, was characterized using an improved multilocus variable-number tandem-repeat analysis (MLVA). The MLVA method was established based on eight primer pairs targeting seven variable-number tandem-repeat (VNTR) loci in two 4-plex fluorescent PCRs. Diversity indices and amplification rates of the individual VNTR loci ranged from 0.38 to 0.92 and from 0.64 to 0.99, respectively. MLVA types and pulsed-field gel electrophoresis (PFGE) patterns were compared using Comparative Partitions analysis involving 336 clinical and 99 food and environmental isolates. The analysis yielded Simpson''s diversity index values of 0.998 and 0.992 for MLVA and PFGE, respectively, and adjusted Wallace coefficients of 0.318 when MLVA was used as a primary subtyping method and 0.088 when PFGE was a primary typing method. Statistical data analysis using BioNumerics allowed for identification of at least 8 predominant and persistent L. monocytogenes MLVA types in Ontario''s food chain. The MLVA method correctly clustered epidemiologically related outbreak strains and separated unrelated strains in a subset analysis. An MLVA database was established for the 2,421 L. monocytogenes isolates, which allows for comparison of data among historical and new isolates of different sources. The subtyping method coupled with the MLVA database will help in effective monitoring/prevention approaches to identify environmental contamination by pathogenic strains of L. monocytogenes and investigation of outbreaks.     

Whole-Genome Shotgun Sequencing of a Colonizing Multilocus Sequence Type 17 Streptococcus agalactiae Strain

This report highlights the whole-genome shotgun draft sequence for a Streptococcus agalactiae strain representing multilocus sequence type (ST) 17, isolated from a colonized woman at 8 weeks postpartum. This sequence represents an important addition to the published genomes and will promote comparative genomic studies of S. agalactiae recovered from diverse sources.     

New Traditions from Nigeria: Seven Artists of the Nsukka Group

New Traditions from Nigeria: Seven Artists of the Nsukka Group. Simon Ottenberg. Washington, DC: Smithsonian Institution Press, 1998. 302 pp.     

Serological diagnosis of Parelaphostrongylus tenuis infection in white-tailed deer and identification of a potentially unique parasite antigen

Serological diagnosis of Parelaphostrongylus tenuis infection should offer many advantages over the currently used method of fecal analysis that relies on a patent infection. Toward this end, we investigated the presence of P. tenuis-specific antibodies in experimentally infected white-tailed deer (WTD) and of unique P. tenuis antigens that may be exploited for serodiagnosis. WTD infected with 6, 20 or 100-150 P. tenuis third-stage larvae (L3) had anti-parasite antibodies from as early as 21 days postinoculation (dpi) until the end of the experiment (147 dpi). Peak anti-P. tenuis enzyme-linked immunosorbent assay (ELISA) titers in individual animals ranged from 1:70 to 1:5,700. Serum from infected WTD reacted with 5 distinct P. tenuis L3 antigens (105, 45, 37, 32, and 19 kDa) as detected by the immunoblotting technique. Serum from caribou infected with Parelaphostrongylus andersoni or Elaphostrongylus rangiferi reacted with all antigens except the 37-kDa antigen of L3, indicating that it may be unique to P. tenuis and can serve as a serodiagnostic antigen. The 37-kDa antigen appears to be present in the adult P. tenuis but not adult E. rangiferi or E. cervi. The development of an ELISA utilizing the unique antigen of P. tenuis should lead to a reliable diagnostic assay for P. tenuis infection in WTD.     

The Impact of Integrated Community Case Management of Childhood Diseases Interventions to Prevent Malaria Fever in Children Less than Five Years Old in Bauchi State of Nigeria

Background

Malaria accounts for about 300,000 childhood deaths and 30% of under-five year old mortality in Nigeria annually. We assessed the impact of intervention strategies that integrated Patent Medicines Vendors into community case management of childhood-diseases, improved access to artemisinin combination therapy (ACT) and distributed bed nets to households. We explored the influence of household socioeconomic characteristics on the impact of the interventions on fever in the under-five year olds in Bauchi State Nigeria.

Methods

A cross-sectional case-controlled, interventional study, which sampled 3077 and 2737 under-5 year olds from 1,588 and 1601 households in pre- and post-intervention periods respectively, was conducted from 2013 to 2015. Difference-in-differences and logistic regression analyses were performed to estimate the impact attributable to the interventions: integrated community case management of childhood illness which introduced trained public and private sector health providers and the possession of nets on the prevalence of fever.

Results

Two-week prevalence of fever among under-fives declined from 56.6% at pre-intervention to 42.5% at post-intervention. Fever-prevention fraction attributable to nets was statistically significant (OR = 0.217, 95% CI: 0.08–0.33). Children in the intervention group had significantly fewer incidence of fever than children in the control group had (OR = 0.765, 95% CI: 0.67–0.87). Although being in the intervention group significantly provided 23.5% protection against fever (95% CI: 0.13–0.33), the post-intervention likelihood of fever was also significantly less than at pre-intervention (OR = 0.57, 95% CI: 0.50–0.65). The intervention protection fraction against fever was statistically significant at 43.4% (OR = 0.434, 95% CI: 0.36–0.50). Logistic regression showed that the odds of fever were lower in households with nets (OR = 0.72, 95% CI: 0.60–0.88), among children whose mothers had higher education, in the post-intervention period (OR = 0.39, 95% CI: 0.33–0.46) and in the intervention group (OR = 0.52, 95% CI: 0.48–0.66). The odds of fever increased with higher socio-economic status of households (17.9%-19.5%). Difference-in-differences showed that the interventions significantly reduced occurrence of fever in the intervention group (OR = 1.70, 95% CI: 1.36–2.14).

Conclusion

The interventions were effective in reducing the prevalence and the likelihood of childhood malaria fever. Taken to scale, these can significantly reduce the burden of malaria fever in the under-five year old children.     

Selection,Recombination, and Virulence Gene Diversity among Group B Streptococcal Genotypes

Transmission of group B Streptococcus (GBS) from mothers to neonates during childbirth is a leading cause of neonatal sepsis and meningitis. Although subtyping tools have identified specific GBS phylogenetic lineages that are important in neonatal disease, little is known about the genetic diversity of these lineages or the roles that recombination and selection play in the generation of emergent genotypes. Here, we examined genetic variation, selection, and recombination in seven multilocus sequence typing (MLST) loci from 94 invasive, colonizing, and bovine strains representing 38 GBS sequence types and performed DNA sequencing and PCR-based restriction fragment length polymorphism analysis of several putative virulence genes to identify gene content differences between genotypes. Despite the low level of diversity in the MLST loci, a neighbor net analysis revealed a variable range of genetic exchange among the seven clonal complexes (CCs) identified, suggesting that recombination is partly responsible for the diversity observed between genotypes. Recombination is also important for several virulence genes, as some gene alleles had evidence for lateral gene exchange across divergent genotypes. The CC-17 lineage, which is associated with neonatal disease, is relatively homogeneous and therefore appears to have diverged independently with an exclusive set of virulence characteristics. These data suggest that different GBS genetic backgrounds have distinct virulence gene profiles that may be important for disease pathogenesis. Such profiles could be used as markers for the rapid detection of strains with an increased propensity to cause neonatal disease and may be considered useful vaccine targets.Group B Streptococcus (GBS) is a leading cause of neonatal sepsis, pneumonia, and meningitis (51) and causes infections in pregnant women, nonpregnant adults, and the elderly with underlying medical conditions. Maternal GBS colonization is a main risk factor for neonatal disease, and roughly 20 to 40% of pregnant women are colonized (14, 23). Colonization rates of up to 31% and 34% have been documented in young men (4) and nonpregnant women (4, 42), respectively, whereas a rate of 22% has been observed in individuals over 65 years of age (18). GBS has also been identified as the cause of bovine mastitis in up to 45% of symptomatic bovines (30). Nine distinct polysaccharide capsule types (serotypes) are known, and the serotype distribution varies by population.The genetic diversity of GBS populations has been studied using a variety of different methods, including restriction fragment length polymorphism (RFLP) (24), ribotyping (5, 25), pulsed-field gel electrophoresis (49), multilocus enzyme electrophoresis (MLEE) (45), random amplification of polymorphic DNA (36), restriction digestion pattern (RDP) typing (53), and multilocus sequence typing (MLST) (28). By utilizing methods that focus on conserved genetic changes within GBS strains, virulent GBS clones that have diversified genetically can be identified. Both MLEE and MLST can distinguish the major GBS serotype III clones associated with neonatal invasive disease as sequence type 17 (ST-17) in the MLST system (28, 29, 38) or electrophoretic type 1 in the MLEE system (45). This clone is also evident in the RDP system as RDP-III (53).A recent study of 75 GBS strains representing different sources and STs reported that the ST-17 lineage is relatively homogeneous and contains a unique set of surface proteins (9). Homogeneity within a GBS lineage that is significantly associated with neonatal disease is likely important for disease pathogenesis, though few studies have been conducted to identify specific differences in virulence characteristics between lineages. Similarly, the roles of selection and recombination in the generation of STs, as well as known virulence genes, have only recently been explored and require further investigation (9a). Here, we assess the genomic diversity of GBS strains representing a variety of common clonal genotypes, examine evidence for selection and recombination, and evaluate the extent of DNA polymorphism and allelic variation in several putative virulence genes.     

CR3 (CD11b/CD18) is the major macrophage receptor for IgM antibody-mediated phagocytosis of African trypanosomes: diverse effect on subsequent synthesis of tumor necrosis factor alpha and nitric oxide

Immunoglobulin M (IgM) antibodies to the variant surface glycoproteins (VSG) of African trypanosomes are the first and predominant class of anti-trypanosomal antibodies in the infected host. They are a major factor in controlling waves of parasitemia, but not in long-term survival. The macrophage receptor(s) that enables phagocytosis of IgM anti-VSG-coated African trypanosomes is unknown. We assessed whether complement receptor CR3 (CD11b/CD18) might be involved in mediating phagocytosis of Trypanosoma congolense. We show that murine complement C3 fragments are deposited onto T. congolense when the trypanosomes are incubated with IgM anti-VSG and fresh mouse serum. In the presence of fresh mouse serum, there is significantly and markedly less phagocytosis of IgM-opsonized T. congolense by CD11b-deficient macrophages compared to phagocytosis by wild-type macrophages (78% fewer T. congolense are ingested per macrophage). Significantly less tumor necrosis factor (TNF)-alpha (38% less), but significantly more nitric oxide (NO) (63% more) are released by CD11b-deficient macrophages that have engulfed trypanosomes than by equally treated wild-type macrophages. We conclude that CR3 is the major, but not the only, receptor involved in IgM anti-VSG-mediated phagocytosis of T. congolense by macrophages. We further conclude that IgM anti-VSG-mediated phagocytosis of T. congolense enhances synthesis of disease-producing TNF-alpha and inhibits synthesis of parasite-controlling NO. We suggest that signaling of inhibition of NO synthesis is mediated via CR3.