Global trend of Methicillin-resistant Staphlococcus aureus and emerging challenges for control

Background: Following its first recognition in early 1960s, the increasing incidence of nosocomial and community-acquired methicillin resistant Staphylococcus aureus (MRSA) infections has become a global problem. The emergence of multiple-drug resistant MRSA strains and dissemination of epidemic antibiotic clones including presence of wide spectrum of virulence and predisposing risk factors complicate diagnosis, chemotherapy and control causing significant morbidity and mortality. Detection of MRSA strains in domestic animals and protozoan has widened the epidemiologic characters of the organism and may influence infection control policies. Objectives: To review the emergence and epidemiologic spread of resistant strains of MRSA, molecular/genetic basis of resistance in the organism and challenges facing control strategies worldwide. It also aims to suggest intervention strategies so as to checkmate the spread of MRSA infections.Methods: By reviewing local and international literatures on MRSA infections coupled with practical experience in the field of this endeavour. Result/Conclusion: MRSA has shown increasing endemic and epidemic spread in the last four decades causing serious medical and socio-economic difficulties. Routine and regular surveillance (uncommon in poor-resourced developing areas of especially sub-Saharan Africa), good hospital practices and personal hygiene, public enlightenment, development of effective therapeutic agents and rational administration of antibiotics based on reliable test results will limit the spread of MRSA infections.Key words: MRSA, incidence, morbidity, mortality, surveillance, control

Characterisation and reproductive biology of four Physalis L. species from Ile-Ife, Nigeria

The nutritional, medicinal and economic values of many Physalis species have been established. However, some Physalis species in Nigeria have been used interchangeably or misidentified. Consequently, there is the need to re-affirm the taxonomic status of these species. Morphological characters and SDS-PAGE were employed to identify and reveal the genetic relationship that exits among the four Physalis species studied. Furthermore, pollen fertility, pollination and germination studies were carried out in order to compile relevant information on reproductive biology of these Physalis species. The results revealed that all the four species studied are annuals. Physalis peruviana has the longest life span. The mean height of the four species studied ranged from 48.08±6.11 to 97.20±6.51 cm with the highest recorded in P. peruviana. The morphological characters subjected to SLCA grouped P. pubescens and P. peruviana together and branched at higher levels of similarity (0.98). In addition, SDS-PAGE showed that P. peruviana, P. angulata and P. pubescens are distantly related to P. micrantha. High pollen stainability (80.6% - 92.6%) was recorded in all the Physalis species studied. Therefore, from this study, it can be concluded that all the four species studied are distinct species with a common origin and they are highly fertile

Emerging and re-emerging infectious agents of nosocomial diseases – The need for review of hospital policy and control strategies

Nosocomial infections (NIs, now referred to as Healthcare-associated infections, HCAIs) are diseases that essentially originate from the hospital and may be disseminated via biologic or inanimate agents in the healthcare center. They occur globally and constitute major hazards inhealthcare institutions resulting in significant morbidity, mortality and increased hospital stay, and high socio-economic cost. Between 3 and 21 percent (average range, 5 – 9%) of all hospitalized patients are affected by HCAIs each year in various communities worldwide; while critically ill,trauma or immunocompromised patients (e.g. those requiring multiple life – saving invasive procedures or immunosuppressive therapy) are hardest hit. The increasing involvement of multiple drug-resistant strains of a large spectrum of emerging and re-emerging infectious agents of NIscomplicate morbidity, management and impose serious burden on the patients and relations. Hospital workers, patients, materials or equipments and hospital procedures constitute major factors of transmission mechanism of HCAIs. However, the incidence and socioeconomic impact ofNIs (though estimated to be high) are rarely investigated in sub-Saharan Africa (including Nigeria) due to poor healthcare facility and low capacity. There is need for increased awareness on HCAIs and adoption of enduring hospital policy and effective control measures that will take cognizanceof emerging trends of nosocomial agents and transmission mechanism to reduce morbidity, mortality and socio-economic impact associated with HCAIs.Keywords: Healthcare – associated infections, hazards, morbidity, mortality, control measures

Emergence of ebola virus disease and its devastating impact in poor-resourced areas of sub-Saharan Africa

Ebola virus disease (EVD) is an unusual infection, and one of the most virulent emerging viral diseases known causing severe morbidity and significant mortality. In recent epidemic outbreak of EVD in West African countries of Guinea, Sierra Leone and Liberia (the 3 nations epi-centre of the epidemic), the disease has affected over 25,000 people resulting in more than 10,000 deaths, (Case Fatality Rate, CFR>40%; i.e. from December, 2013-March, 2015). Following the first outbreak of EVD in Sudan and Democratic Republic of Congo (DRC) in 1976, several epidemics (>20 outbreaks) of the disease have been recorded particularly in poor-resourced areas of the East, Central and West-Africa resulting in significant mortality. CFR of EVD is 25-90 percent. Ebola virus is transmitted to humans by wild animals (mainly non-human primates) and spreads in human population via close contact with blood, body fluids and secretions of infected patients. EVD can also be acquired through direct contact with infected corpses. It is characterized (at initial stage) by non-specific flu-like symptoms including headache, fever, myalgia and malaise following incubation period of 2-21 days. This may terminate into severe systemic manifestations including diffuse internal and external bleeding, shock and death if untreated early. Non recognition of the specific natural host of Ebola virus and rapid progression of infection including slow mounting of acquired immunity against EVD by infected host complicate control measures. The socio-economic cost of EVD epidemic outbreak is colossal. Despite notable advances in healthcare-related technology enhancing the diagnosis, treatment / management and prevention / control of infectious or viral diseases, the response of the stakeholders over the years geared toward controlling the spread of the disease left much to be desired. No clinically certified drugs or vaccines against EVD are yet available. There is the urgent need by stakeholders to device appropriate preventive / control measures including development of effective drugs and vaccines to checkmate the spread of EVD and associated severe morbidity, high mortality and devastating socio-economic impact.Key Words: Ebola virus disease, severe morbidity, mortality, socio-economic impact, checkmate

DYNAMICS OF CARBON, NITROGEN, PHOSPHORUS AND POTASSIUM UNDER DIFFERENT Tithonia diversifolia MANAGEMENT SYSTEMS IN A TROPICAL ALFISOL: A GREENHOUSE BIOASSAY

The research investigated the dynamics of C, N, P and K under different Tithonia management options.Changes in soil N and P showed significant increase in these nutrients in treatment with incorporatedTithonia + NPK and Mulched Tithonia + NPK respectively. There was a reduction in the soil K at6 WAP in all the treatments except those with NPK and mulched Tithonia. Generally, there was a sustainedincrease in soil organic carbon in all the treatments. There was an increase in N and P contentsof maize plant with successive cycles thus indicating residual effect, most pronounced in treatmentwith incorporated Tithonia + NPK. However, there is the need for K supplementation at the secondmaize cycle. Maize biomass yield indicated the possibility of two cycles with mulched or incorporatedTithonia + NPK fertilizers as most promising option. Economic feasibility should, however, be considered

Review of Lassa fever, an emerging old world haemorrhagic viral disease in sub-Saharan Africa

Lassa fever is an acute immunosuppressive illness of increasing public health concern causing severe morbidity and significant mortality (Case fatality rate (CFR) ≥ 50%) especially in epidemic cases. Although Lassa fever has emerged (following its first detection (1969) in Lassa town, Nigeria) as one of the most prevalent and debilitating viral haemorrhagic fevers endemic in West Africa region (Nigeria inclusive), yet, the control/prevention of the regular outbreak of the disease has become an herculean task in the areas affected; there is inadequate healthcare facility (including Laboratory/diagnostic and care centres), poor socioeconomic environment, lack of awareness among the populace and presence of favourable ecologic niche for the survival and propagation of the natural host and reservoir mouse (Mastomys natalensis) of Lassa virus . Lassa fever is mainly transmitted by contact with excretions and secretions of infected rats via foods and water as well as exposure to other contaminated items. Lassa virus is a member of an Old World Arenariruses, of family Arenaviridae. It is an enveloped, single-stranded (SS) bisegmented RNA virus with ability to replicate very rapidly. It consists of 4 lineages; 3 members are identified as ancenstral strains found in Nigeria, while the fourth is domiciled in other West Africa Countries. Lassa virus infects almost every tissue in human body resulting in multisystemic dysfunction. The incubation period is generally between 6 to 21 days resulting in 3 stages of clinical manifestation viz: Acute phase characterized by flu-like, non-specific illness; haemorrhagic phase accompanied with gastrointestinal symptoms and cardiovascular/neurologic complications. Currently, there is no clinically certified Lassa fever vaccine thus complicating deterrent or preventive measures. Hence, there is need for intensification of educational programs for the populace on the useful control measures against Lassa fever. The stakeholders need to prioritize intervention and support program and also speed up the processes leading to the production of effective vaccine to limit the menace of Lassa fever outbreak and associated morbidity, fatality and high socio-economic cost.Keywords: Lassa fever, endemic, epidemic, reservoir rodent, West Afric

Karyotypic studies of four Physalis species from Nigeria

Mitotic chromosomes from root tips of four Nigerian Physalis species were investigated using standard cytogenetic methods. P. angulata has chromosome number of 2n = 48 with karyotypic formula of 2M + 5m + 16sm + 1st, while P. micrantha, P. peruviana and P. pubescens showed the same chromosome number of 2n = 24 with karyotypic formulae of 1M + 1m + 9sm + 1st, 4M + 6m + 1sm + 1st and 1M + 1 m + 2sm + 8st, respectively. The karyotypes show that P. angulata is more advanced when compared to the other three diploids studied

Bus Rapid Transit and Socioeconomic Condition of Bus Commuters in Lagos State

Road transport is one of the most common means of transportation across the world. Bus transportation in Nigeria had witnessed many problems for the past decades considering the growing population with the attendant loss of lives and properties in most cities like Lagos in Nigeria. This paper focuses on the adequacy of services provided by Bus Rapid Transit (BRT) in Lagos State with respect to the extent to which it influences the socioeconomic conditions of bus commuters.  It examines the effect of services rendered by BRT on cost reduction potential, income and safety. Multistage sampling technique was used to select 20 samples each from all respondents in all local government area in Lagos State to reach a total of three hundred and thirty (330) samples. The data collection instrument was the questionnaire which was validated. Data collected were analysed with the use of descriptive statistics such as means, percentages and standard deviation and inferential statistics such as regression and analysis of variance techniques. Findings showed that BRT services has reduced the cost of bus commuters and also increased safety and security thereby increasing the socioeconomic condition of Lagosians. The study recommends improvements in BRT services through the deployment of technology as it had been used in developed countries. &nbsp

Evaluation of Silver Nanoparticle Encapsulation in DPPC-Based Liposome By Different Methods For Enhanced Cytotoxicity

Here we carried out a comparative study on two cost and time effective methods of encapsulating silver nanoparticles (AgNP) in dipalmitoyl-phosphatidyl choline (DPPC)/cholesterol-based liposome to enhance nanoparticle cytotoxicity, and evaluated the effect of this on a blood cell line (THP1 monocytes) often involved in uptake of nanoparticles during human exposure. DLS and Zeta potential analyses over a 6-months period showed the extruded Lipo-AgNP (Ex-Lipo-AgNP) exhibited more stable characteristics when compared with the probe-sonicated Lipo-AgNP (PB-Lipo-AgNP). SEM microscopy indicated agglomeration of the PB-Lipo-AgNP which was not observed in Ex-Lipo-AgNP. Ex-Lipo-AgNP also exhibited higher temperature-dependent stability with 35.3% reduction in size from 20 °C to 37 °C while PB-Lipo-AgNP was less stable exhibiting 55% size reduction over same temperature range and 6 h period. Load release study over 24 h showed controlled release from Ex-Lipo-AgNP while the PB-Lipo-AgNP exhibited burst release at pH 4 and 6.5. Interestingly, it was found that Ex-Lipo-AgNP induced significantly higher cytotoxicity on THP1 cell line after 24 h exposure compared with control unexposed cells, uncoated AgNP and PB-Lipo-AgNP exposed cells at the same concentration. Thus, we report here that liposomal encapsulation of AgNP by extrusion produces a stable nanocapsule with enhanced cytotoxicity, thus preventing overreliance on high AgNP concentration to achieve desired toxicity for in vitro and possible in vivo applications

Surface Modification of Silver Nanoparticle (AgNP) by Liposomal Encapsulation Mitigates AgNP-Induced Inflammation

Silver nanoparticles (AgNP) are widely used in a variety of consumable products as antibacterial to prevent or treat infection. Unfortunately, evidence exits that AgNP induces inflammation which can worsen with repeated human exposure. However, there is little or no research on how to mitigate these adverse effects due to AgNP induced-toxicity. Here, we investigated if surface modification of AgNP by liposomal encapsulation suppresses AgNP-mediated inflammatory responses in THP1 monocytes and THP1 differentiated macrophages (TDM). AgNP was encapsulated in a dipalmitoyl phosphatidyl choline- (DPPC)/cholesterol-based liposome by extrusion through a 100-nm polycarbonate membrane to form Lipo-AgNP. It was found as expected that AgNP induced significant release of IL-1β, IL-6, IL-8 and TNF-α in THP1 monocytes more than the basal level. Interestingly, release of these cytokines was suppressed by Lipo-AgNP. In TDMs, AgNP and Lipo-AgNP induced IL-8 release (p \u3c .0001), but Lipo-AgNP maintained IL-8 release at levels significantly lower than that of AgNP (p \u3c .01). However, both AgNP and Lipo-AgNP suppressed IL-1β and TNF-α release in LPS-stimulated THP1 monocytes and LPS-stimulated or unstimulated TDM respectively. We finally showed that Lipo-AgNP inhibits STAT-3 and this may be responsible for regulating the uncontrolled inflammation induced by AgNP likely mediated STAT-3 protein expression in LPS stimulated THP1 monocytes and TDMs, both LPS-stimulated and unstimulated. This data showed that Lipo-AgNP suppressed AgNP induced inflammation, making Lipo-AgNP particularly useful in treatment of bacteria induced inflammatory diseases and inflammatory cancers