Martha Mesembe

Relationship between multiple drug resistance and biofilm formation in Staphylococcus aureus isolated from medical and non-medical personnel in Yaounde, Cameroon

Introduction Monitoring the prevalence of nasal carriage of multiple drug resistance (MDR) Staphylococcus aureus (SA) strains in hospital personnel is essential. These strains when transmitted from hospital personnel to patients with already weakened immune states or in-built medical devices, may limit the latters treatment options. This study aimed at assessing the potential exposure of patients to these MDR SA in a resource-limited hospital setting by assessing the prevalence and relationship between antimicrobial susceptibility and biofilm forming capacity of SA isolates from hospital personnel. Methods A total of 59 bacteria isolates phenotypically identified as Staphylococcus aureus obtained from medical (39) and non-medical personnel (20) in Yaounde were used in the study. Multiple drug resistance defined as resistance to four or more of twelve locally used antibiotics were determined by Kirby Bauer disc diffusion technique whereas quantification of biofilm production was by the microtitre plate method. Results Among the 59 SA isolates, the prevalence of MDR was 50.9%. Among medical personnel 48.7% had MDR as against 55.9% for non-medical personnel (p-value=0.648). The overall percentage of weak biofilm producers was 35.6%. Although the prevalence of weak biofilm formers was higher in isolates from non-medical personnel (40%) than medical personnel (33.3%) the difference was not statistically significant (p-value= 0.246). Slightly less than half (42.9%) of the weak biofilm producers were MDR. Conclusion Considering the high rates of MDR and that slightly less than half of biofilm formers were MDR, these trends need to be monitored regularly among hospital personnel in Yaounde.

Plasma concentrations of soluble Fas receptors (Fas) and Fas ligands (FasL) in relation to CD4+ cell counts in HIV-1 positive and negative patients in Yaounde, Cameroon

BackgroundThough documented that HIV infection progresses with the depletion of CD4+ cells, the exact mechanisms by which these cell depletions occur are not clearly understood. This study aimed at evaluating the plasma levels of soluble Fas receptors and ligands in HIV-infected and uninfected patients in Yaounde, Cameroon, a population with a known diversity of HIV in whom this has not been previously assessed.FindingsIn a cross-sectional study, 39 antiretroviral naïve HIV-1 positive and negative participants were recruited in Yaounde, Cameroon. CD4+ lymphocyte cell counts were quantified from whole blood using an automated FACScount machine (Becton-Dickinson, Belgium). Plasma samples obtained were analyzed for soluble Fas receptors and Fas ligands in both HIV-1 positive and negative samples using two different quantitative sandwich ELISA kits (Quantikine®, R&D Systems , UK).Plasma levels of Fas receptors were higher in HIV-1 positive patients (median = 1486pg/ml IQR = 1193, 1830pg/ml) compared to HIV-negative controls (median = 1244pg/ml, IQR = 1109, 1325pg/ml), p-value <0.001. Plasma levels of Fas ligands were also higher in HIV-1 positive patients (median = 154pg/ml, IQR = 111, 203pg/ml) compared to HIV-negative controls (median = 51pg/ml, IQR = 32, 88pg/ml), p-value = 0.005. Plasma concentrations of soluble fas receptors and ligands tended to be negatively correlated with the CD4+ cell counts of HIV-positive patients; the correlation coefficients were -0.34 (value = 0.78) and-0.3 (p-value = 0.51) respectively.ConclusionsIn this population of patients in Cameroon, plasma concentrations of Fas receptors and Fas ligands tend to be higher in HIV-positive patients. The Fas pathway of apoptosis may have a role in the depletion of CD4+ cell counts

Resistance pattern of enterobacteriaceae isolates from urinary tract infections to selected quinolones in Yaoundé

Introduction It is estimated that 150 million urinary tract infections (UTIs) occur yearly worldwide, resulting in more than 6 billion dollar in direct healthcare cost. The etiology of UTIs is predictable, with Escherichia coli, an Enterobacteriaceae being the principal pathogen. Quinolones are usually the drug of choice. In this study, we report the resistance pattern of Enterobacteriaceae isolates from UTIs to quinolones among in-patients and out-patients at the Yaoundé Reference Hospital in Cameroon. Methods A cross-sectional descriptive study was carried out for a ten-month period. Consecutive clean-catch mid-stream urine samples were collected from 207 in and out-patients. Identification was done using the Api 20E, and susceptibility testing using the Kirby Bauers disc diffusion method and the MIC was done using the E-test. Results Out of the 207 isolates, 58(28.0%) were found to be resistant to all the quinolones used in the study. The resistances observed by species were in the order: Enterobacter 4(30.8%); Klebsiella 19(29.7%); Escherichia 25 (29.4%); Proteus 2(11.8%); Serratia 4(25.0%). Quinolone resistance for Escherichia was 42.9% for In-Patients (IP) and 16.3% for Out-Patient (OP) (P-value = 0.006); Klebsiella 35.9% for IP and 20% for OP; Proteus 11.1% for IP and 12.5% for OP; Serratia 18.2% for IP and 40% for OP; Enterobacter 22.2 for IP and 50% for OP. Conclusion High resistance rates to quinolones were observed not only for in-patients but also for out-patients with urinary tract enterobacterial infections. These findings demonstrate the importance of antibiotics susceptibility testing in improving quinolones prescription practices in Cameroon.

Chronic obstructive pulmonary disease (COPD) : neutrophils, macrophages and lymphocytes in patients with anterior tuberculosis compared to tobacco related COPD

ObjectiveThe inflammatory profile of chronic obstructive pulmonary disease (COPD) related to tobacco is known in certain studies while that of the post tuberculosis form is not yet known. This study aimed to evaluate the levels of neutrophils, macrophages and lymphocytes cells in sputum of COPD patients with history of smoking or anterior tuberculosis. Enumeration of cells in samples was analyzed using standard microscopy.ResultsWe enrolled 92 participants, 46 (50%) were COPD subjects comprising 22 (47.83%) smokers and 24 (52.17%) with anterior tuberculosis while 46 (50%) healthy persons constituted the control group. The levels of neutrophils, lymphocytes and monocytes were statistically higher in COPD patients compared to the control group with p-values of 0.0001 respectively. Neutrophils levels were higher in COPD patients with history of tobacco than in COPD patients with anterior tuberculosis with a mean rate of 4.72 × 106/ml and 2.48 × 106/ml respectively (p = 0.04). The monocytes and lymphocytes levels were not statistically different between the two sub-groups of COPD patients with p-value of 0.052 and 0.91 respectively. Neutrophils are the only inflammatory cells that were significantly higher in COPD patients with history of smoking as compared to COPD patients with anterior tuberculosis.

Observed HIV drug resistance associated mutations amongst naïve immunocompetent children in Yaoundé, Cameroon

Introduction The emergence of drug resistance mutations (DRMs) has been a major threat for successful lifelong combination antiretroviral therapy (cART), especially for HIV-vertically infected children within the context of the prevention of mother-to-child transmission (PMTCT). This study aimed to evaluate DRMs amongst immune competent treatment-naïve children in Cameroon. Methods A cross-sectional study was conducted between 2015 and 2016 amongst 55 proxy consented HIV-1 positive children, aged 9 months to 6 years. They were all immune competent, cART naïve and with unknown history of PMTCT. CD4 cell counts and genotypic drug resistance testing were performed using standard methods. Results Levels of DRMs to protease (PR) inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-NRTIs were 27.6%, 3.7% and 40.7%, respectively. Only minor DRMs were observed for PR. The observed mutations for NRTI were K65R, T215I and K219E (33.0% each) and for NNRTI: V106M, Y181C and Y188H (6.0% each). Only minor accessory mutations were found in the integrase (IN) region. Conclusion Despite widely available cART we still observe naïve HIV children, especially from the rural communities. We observe that a proportion of study participants had HIV-1 drug resistance associated mutations (RAMs). Data generated could help strengthen the current PMTCT programmes within the country. There is a need to upscale approaches for drug resistance testing for children in Cameroon and many other resource-limited settings.

The Potentials of Fas Receptors and Ligands in Monitoring HIV-1 Disease in Children in Yaoundé, Cameroon

Objective: Difficulties in systematically monitoring HIV viral load in resource-limited settings prompt the search for alternate approaches. The authors aimed at assessing the correlation between the plasma levels of soluble forms of Fas receptors (Fas) and Fas ligands (FasL) with standard indicators of HIV disease progression in children. Methods: Twenty-two HIV-1-positive children were enrolled in Yaounde. CD4 counts, CD4% counts, plasma levels of Fas, FasL, and HIV-1 RNA levels were assayed. Results: The correlation coefficients (P values) between FasL levels and each of HIV-1 viral load, CD4 counts, and CD4% were, respectively, .56 (.01), −.29 (.18), and .30 (.18). On the other hand, the respective correlation coefficients (P values) with Fas levels were .12 (.60), −.30 (.18), and −.29 (.19). Conclusion: The significant correlation between levels of HIV-1 viral load and FasL suggests that the latter needs to be further studied as a potential biomarker to monitor HIV-1 disease progression in children in resource-limited setting.