Cooccurrence of Predominant Panton-Valentine Leukocidin-Positive Sequence Type (ST) 152 and Multidrug-Resistant ST 241 Staphylococcus aureus Clones in Nigerian Hospitals

Ninety-six clinical isolates of Staphylococcus aureus from Nigeria were characterized phenotypically and genetically. Twelve multidrug-resistant methicillin (meticillin)-resistant S. aureus (MRSA) isolates carrying a new staphylococcal cassette chromosome mec element and a high proportion of Panton-Valentine leukocidin (PVL)-positive methicillin-susceptible S. aureus (MSSA) isolates were observed. The cooccurrence of multidrug-resistant MRSA and PVL-positive MSSA isolates entails the risk of emergence of a multidrug-resistant PVL-positive MRSA clone.Staphylococcus aureus is a major cause of both hospital- and community-acquired infections. In particular, methicillin (meticillin)-resistant S. aureus (MRSA) strains have been detected worldwide (15), and the prevalence of MRSA varies among countries and health institutions (2, 4, 27). The emergence of MRSA strains resistant to glycopeptides, as well as the increasing prevalence in the community (7), highlights the need for worldwide epidemiological studies of this pathogen. However, data about the epidemiology and prevalence of staphylococcal infections in Africa are scarce compared to information about such infections in the rest of the world. Studies have indicated low prevalences of MRSA in Nigeria, Somalia, and Tanzania (1), but high prevalences in South Africa, Zimbabwe, Kenya, Ethiopia, Egypt, Senegal, and the Ivory Coast have been reported (2, 9, 18). In addition, a recent study of the genetic diversity of S. aureus strains in a carriage population from Mali showed a high frequency of a Panton-Valentine leukocidin (PVL)-positive clone (25). The mechanisms for the emergence and spread of S. aureus clones in Africa are largely unknown; hence, the characterization of isolates may provide baseline information needed in establishing effective infection control measures in Nigeria.In this study, a total of 96 S. aureus isolates obtained between January and December 2007 from clinical specimens in six tertiary-care hospitals located in northeastern Nigeria were characterized. The isolates were identified based on standard bacteriological procedures (i.e., Gram staining and catalase, tube coagulase, and DNase testing), and susceptibilities to 12 antibiotics (Table ​(Table1)1) were determined by the disk diffusion method according to the CLSI guidelines. All the isolates were susceptible to vancomycin, fusidic acid, and mupirocin, and 12 (12.5%) were resistant to methicillin (i.e., oxacillin and cefoxitin resistant) (Table ​(Table1).1). The MRSA isolates were multidrug resistant (i.e., resistant to beta-lactams, along with at least three other classes of antibiotics), a finding similar to previously reported findings in other African countries like Morocco, Kenya, Cameroon, and South Africa (17). MRSA resistance to non-beta-lactams may further increase the medical expenses and the complexity of patient management, as well as morbidity and mortality rates since alternative antibiotics may not be affordable in many African countries.

TABLE 1.

Frequency of resistance of S. aureus (MSSA and MRSA) isolates to antibiotics

Effect of Tulbaghia violacea on the blood pressure and heart rate in male spontaneously hypertensive Wistar rats

Ethnopharmacological relevance

Tulbaghia violacea Harv. (Alliaceae) is a small bulbous herb which belongs to the family Alliaceae, most commonly associated with onions and garlic. In South Africa, this herb has been traditionally used in the treatment of various ailments, including fever, colds, asthma, paralysis, hypertension and stomach problems. The aim of this study was to evaluate the effect of methanol leaf extracts (MLE) of Tulbaghia violacea on the blood pressure (BP) and heart rate (HR) in anaesthetized male spontaneously hypertensive rats; and to find out the mechanism(s) by which it acts.

Materials and methods

The MLE of Tulbaghia violacea (5–150 mg/kg), angiotensin I human acetate salt hydrate (ang I, 3.1–100 μg/kg), angiotensin II human (ang II, 3.1–50 μg/kg), phenylephrine hydrochloride (phenylephrine, 0.01–0.16 mg/kg) and dobutamine hydrochloride (dobutamine, 0.2–10.0 μg/kg) were infused intravenously, while the BP and HR were measured via a pressure transducer connecting the femoral artery and the Powerlab.

Results

Tulbaghia violacea significantly (p < 0.01) reduced the systolic, diastolic, and mean arterial BP; and HR dose-dependently. Ang I, ang II, phenylephrine and dobutamine all increased the BP dose-dependently. The hypertensive effect of ang I and the HR-increasing effect of dobutamine were significantly (p < 0.01) decreased by their co-infusion with Tulbaghia violacea (60 mg/kg). However, the co-infusion of ang II or phenylephrine with Tulbaghia violacea (60 mg/kg) did not produce any significant change in BP or HR when compared to the infusion of either agent alone in the same animal.

Conclusions

Tulbaghia violacea reduced BP and HR in the SHR. The reduction in BP may be due to actions of the MLE on the ang I converting enzyme (ACE) and β₁ adrenoceptors.     

Single coronary artery syndrome: Cardiac computed tomography angiography as a leading imaging modality

Single coronary artery syndrome is usually an asymptomatic condition in most patients; thus most patients are diagnosed when noninvasive imaging (cardiac computed tomography angiography, cardiac magnetic resonance) or invasive coronary angiography is done for evaluation for other cardiac conditions. With advances using cardiovascular imaging in the evaluation and management of single coronary artery syndrome; Cardiac Computed Tomography Angiography (CCTA) has emerged as a very essential and leading imaging modality. CCTA has the best resolution (spatial and temporal) among the imaging modalities available for analyzing the cardiovascular system for the diagnosis and management of single coronary artery syndrome. We are presenting cases of patients with single coronary artery syndrome with 3 different courses (anterior, septal, inter‐arterial), illustrating how CCTA gives a detailed anatomic/structural evaluation of the origin and course of the coronary arteries, and other cardiac structures. Thus in patients diagnosed with single coronary artery syndrome, CCTA can provide vital information on the not only the course, but the associated narrowing of coronary vessels. © 2011 Wiley‐Liss, Inc.     

Community mobilization to reduce postpartum hemorrhage in home births in northern Nigeria

The purpose of this study is to demonstrate the importance of community mobilization in the uptake of a health intervention, namely, community-based distribution of misoprostol to prevent postpartum hemorrhage. Community mobilization to increase access to misoprostol for postpartum hemorrhage prevention was implemented in northwestern Nigeria in 2009. Theories of community participation and the current near-epidemic maternal mortality conditions underpin an approach using modest levels of community involvement. The study was undertaken in five communities around Zaria, Nigeria. Community leaders and selected community members participated in a series of dialogs. Additionally, community education, information and dramas sessions were held. Twenty nine community oriented resource persons (CORPs), 27 drug keepers and 41 traditional birth attendants (TBAs) were involved in the intervention. Postpartum interviews were used to assess the impact of community mobilization efforts and to track use of misoprostol. Multiple logistic regression was used to examine the association between correct use and receiving information regarding misoprostol from TBAs or CORPs. A total of 1875 women were enrolled in the study in 2009. Most women delivered at home (95%) and skilled attendance at delivery was low (7%). Community mobilization efforts reached most women with information about postpartum hemorrhage and misoprostol (88%), resulting in high comprehension of intervention messages. Women identified TBAs and CORPs as the single most important source of information about misoprostol 41% and 31% of the time, respectively. Availability of misoprostol at the community level gave 79% of enrolled women some protection against postpartum hemorrhage which they otherwise would not have had. Although high level community participation in health care interventions is the ideal, this study suggests that even in circumstances where only modest levels of participation can realistically be achieved, community mobilization can have a significant impact on the successful distribution and uptake of a potentially life-saving health intervention, in turn helping promote policy change.