Methicillin-Resistant Staphylococcus aureus Carriage among Neonate Mothers, Healthcare Workers, and Environmental Samples in Neonatal Intensive Care Units: A Systematic Review.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of morbidity and mortality among neonates admitted to neonatal intensive care units (NICUs). The MRSA colonization of neonates, attributed to various sources, including mothers, healthcare workers, and environmental surfaces, can lead to severe infection, prolonged hospital stays, and even death, imposing substantial economic burdens. Given the pressing need to mitigate MRSA spread in these vulnerable environments, further examination of the subject is warranted. This systematic review is aimed at synthesizing available evidence on MRSA carriage proportions among mothers of newborns, healthcare workers, and environmental surfaces in NICUs. Methodology. We included observational studies published in English or French from database inception to March 21, 2023. These studies focused on MRSA in nonoutbreak NICU settings, encompassing healthy neonate mothers and healthcare workers, and environmental surfaces. Literature search involved systematic scanning of databases, including Medline, Embase, Web of Science, Global Health, and Global Index Medicus. The quality of the selected studies was assessed using the Hoy et al. critical appraisal scale. The extracted data were summarized to calculate the pooled proportion of MRSA positives, with a 95% confidence interval (CI) based on the DerSimonian and Laird random-effects model. Results: A total of 1891 articles were retrieved from which 16 studies were selected for inclusion. Most of the studies were from high-income countries. The pooled proportion of MRSA carriage among 821 neonate mothers across four countries was found to be 2.1% (95% CI: 0.3-5.1; I2 = 76.6%, 95% CI: 36.1-91.5). The proportion of MRSA carriage among 909 HCWs in eight countries was determined to be 9.5% (95% CI: 3.1-18.4; I2 = 91.7%, 95% CI: 87.1-94.6). The proportion of MRSA carriage among HCWs was highest in the Western Pacific Region, at 50.00% (95% CI: 23.71-76.29). In environmental specimens from five countries, a pooled proportion of 16.6% (95% CI: 3.5-36.0; I2 = 97.7%, 95% CI: 96.6-98.4) was found to be MRSA-positive. Conclusion: With a significant heterogeneity, our systematic review found high MRSA carriage rates in neonate mothers, healthcare workers, and across various environmental surfaces in NICUs, posing a potential risk of nosocomial infections. Urgent interventions, including regular screening and decolonization of MRSA carriers, reinforcing infection control measures, and enhancing cleaning and disinfection procedures within NICUs, are crucial. This trial is registered with CRD42023407114.

A mapping review of methicillin-resistant Staphylococcus aureus proportions, genetic diversity, and antimicrobial resistance patterns in Cameroon.

BACKGROUND: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has increased and poses a significant threat to human and animal health in Cameroon and the world at large. MRSA strains have infiltrated various settings, including hospitals, communities, and livestock, contributing to increased morbidity, treatment costs, and mortality. This evidence synthesis aims to understand MRSA prevalence, resistance patterns, and genetic characterization in Cameroon. METHODS: The methodology was consistent with the PRISMA 2020 guidelines. Studies of any design containing scientific data on MRSA prevalence, genetic diversity, and antimicrobial resistance patterns in Cameroon were eligible for inclusion, with no restrictions on language or publication date. The search involved a comprehensive search strategy in several databases including Medline, Embase, Global Health, Web of Science, African Index Medicus, and African Journal Online. The risk of bias in the included studies was assessed using the Hoy et al tool, and the results were synthesized and presented in narrative synthesis and/or tables and graphs. RESULTS: The systematic review analyzed 24 studies, mostly conducted after 2010, in various settings in Cameroon. The studies, characterized by moderate to low bias, revealed a wide prevalence of MRSA ranging from 1.9% to 46.8%, with considerable variation based on demographic and environmental factors. Animal (0.2%), food (3.2% to 15.4%), and environmental samples (0.0% to 34.6%) also showed a varied prevalence of MRSA. The genetic diversity of MRSA was heterogeneous, with different virulence gene profiles and clonal lineages identified in various populations and sample types. Antimicrobial resistance rates showed great variability in the different regions of Cameroon, with notable antibiotic resistance recorded for the beta-lactam, fluoroquinolone, glycopeptide, lincosamide, and macrolide families. CONCLUSION: This study highlights the significant variability in MRSA prevalence, genetic diversity, and antimicrobial resistance patterns in Cameroon, and emphasizes the pressing need for comprehensive antimicrobial stewardship strategies in the country.

Genotypic resistance testing improves antiretroviral treatment outcomes in a cohort of adolescents in Cameroon: Implications in the dolutegravir-era.

Acquired drug resistance (ADR) is common among adolescents living with perinatal HIV (APHI) in sub-Saharan Africa (SSA). Personalized management has the potential to improve pediatric antiretroviral therapy (ART), even in the presence of long-term treatment and HIV-1 subtype diversity. We sought to evaluate the effect of HIV-1 mutational profiling on immuno-virological response and ADR among APHI. A cohort-study was conducted from 2018-2020 among 311 APHI receiving ART in Cameroon. Clinical, immunological and virological responses were measured at enrolment (T1), 6-months (T2) and 12-months (T3). Immunological failure (IF: CD4 #x003C;250 cells/mm3), VF (viremia ≥1,000 copies/ml), and ADR were analyzed, with P#x003C;0.05 considered significant. Mean age was 15(±3) years; male-female ratio was 1:1; median [IQR] ART-duration was 36[21-81] months. At T1, T2, and T3 respectively, adherence-level was 66.4, 58.3 and 66.5%; 14 viral clades were found, driven by CRF02_AG (58.6%); ADR-mutations favored increased switch to second-line ART (16.1, 31.2, and 41.9%, P#x003C;0.0001). From T1-T3 respectively, there were declining rates of IF (25.5, 18.9, and 9.83%, P#x003C;0.0001), VF (39.7, 39.9, and 28.2%, P=0.007), and HIVDR (96.4, 91.7, and 85.0%, P=0.099). Predictors of ADR were being on first-line ART (P=0.045), high viremia at enrolment (AOR=12.56, P=0.059), and IF (AOR=5.86, P=0.010). Of note, optimized ART guided by mutational profile (AOR=0.05, P=0.002) was protective. Moreover, full Tenofovir+Lamivudine+Dolutegravir efficacy was predicted in 77 and 62% of APHI respectively after first- and second-line failure. Among APHI in this SSA setting, viral mutational profiling prompts the use of optimized Dolutegravir-based ART regimens, leading to improved immuno-virological response and declining ADR burdens. Thus, implementing personalized HIV medicine in this vulnerable population would substantially improve ART response and the achievement of the 95-95-95 goals in these underserved populations.

Molecular and serological evidence of Crimean-Congo hemorrhagic fever orthonairovirus prevalence in livestock and ticks in Cameroon.

Introduction: Despite a high fatality rate in humans, little is known about the occurrence of Crimean-Congo hemorrhagic fever virus (CCHFV) in Cameroon. Hence, this pioneer study was started with the aim of determining the prevalence of CCHFV in domestic ruminants and its potential vector ticks in Cameroon. Methods: A cross-sectional study was carried out in two livestock markets of Yaoundé to collect blood and ticks from cattle, sheep, and goats. CCHFV-specific antibodies were detected in the plasma using a commercial ELISA assay and confirmed using a modified seroneutralization test. Ticks were screened for the presence of orthonairoviruses by amplification of a fragment of the L segment using RT-PCR. Phylogeny was used to infer the genetic evolution of the virus. Results: Overall, 756 plasma samples were collected from 441 cattle, 168 goats, and 147 sheep. The seroprevalence of CCHFV was 61.77% for all animals, with the highest rate found in cattle (433/441, 98.18%) followed by sheep (23/147, 15.65%), and goats (11/168, 6.55%), (p-value < 0.0001). The highest seroprevalence rate was found in cattle from the Far North region (100%). Overall, 1500 ticks of the Rhipicephalus (773/1500, 51.53%), Amblyomma (341/1500, 22.73%), and Hyalomma (386/1500, 25.73%) genera were screened. CCHFV was identified in one Hyalomma truncatum pool collected from cattle. Phylogenetic analysis of the L segment classified this CCHFV strain within the African genotype III. Conclusion: These seroprevalence results call for additional epidemiological studies on CCHFV, especially among at-risk human and animal populations in high-risk areas of the country.

Diagnosing disseminated histoplasmosis in advanced HIV/AIDS disease in Cameroon using a point of care lateral flow assay.

Histoplasmosis is an AIDS-defining opportunistic infection. Disseminated histoplasmosis (DH) can be fatal without early diagnosis and treatment initiation. We present one confirmed and three probable cases of DH in advanced HIV/AIDS disease patients diagnosed using OIDx Histoplasma LFA in Yaoundé, Cameroon. Four women with HIV but unknown CD4 count presented with asthenia, weight loss, productive cough, and fever (39°C) as common symptoms for at least 3 weeks. Two of the patients had skin lesions. These included facial papules, macules, and umbilicated vesicles scattered over the trunk and limbs. These were diffuse lesions which were purulent, itching, and papillomatous lesions with a necrotic centre, and one patient had a right forearm ulcer. We performed the Histoplasma antigen tests using the OIDx Histo LFA, and they were strongly positive in all four patients. Histopathology in skin biopsy allowed identification of the species as Histoplasma capsulatum var capsulatum in one patient. In this same patient, Pseudomonas aeruginosa and Proteus mirabilis were cultured from the forearm ulcer. This patient later commenced antibiotics (Levofloxacin 500 mg) and oral itraconazole (800 mg/day) with immediate improvement. Unfortunately, the other three patients could not access itraconazole, were discharged and lost to follow-up. Early diagnosis and treatment are essential for the management of DH. LFA is a test that can be set up in any setting with limited resource. Access to this can be a major advance in the diagnosis of histoplasmosis in resource-limited settings.

Seroprevalence of Rift Valley fever virus in domestic ruminants of various origins in two markets of Yaoundé, Cameroon.

BACKGROUND: Rift Valley fever (RVF) is a mosquito-borne zoonosis endemic in Africa. With little known of the burden or epidemiology of RVF virus (RVFV) in Cameroon, this study aimed to determine the seroprevalence of RVFV in domestic ruminants of various origins in two markets of Yaoundé, Cameroon. METHODOLOGY/PRINCIPAL FINDINGS: The origin of animals randomly sampled at two livestock markets in Yaoundé were recorded and plasma samples collected for competitive and capture Enzyme-linked Immunosorbent Assay (ELISA) to determine the prevalence of Immunoglobulins G (IgG) and Immunoglobulins M (IgM) antibodies. Following ELISA IgM results, a real-time reverse transcription-polymerase chain reaction (qRT-PCR) was performed to detect RVFV RNA. In June-August 2019, February-March 2020, and March-April 2021, 756 plasma samples were collected from 441 cattle, 168 goats, and 147 sheep. RVFV IgG seroprevalence was 25.7% for all animals, 42.2% in cattle, 2.7% in sheep, and 2.4% in goats. However, IgM seroprevalence was low, at 0.9% in all animals, 1.1% in cattle, 1.4% in sheep, and 0% in goats. The seroprevalence rates varied according to the animal's origin with the highest rate (52.6%) in cattle from Sudan. In Cameroon, IgG and IgM rates respectively were 45.1% and 2.8% in the North, 44.8% and 0% in the Adamawa, 38.6% and 1.7% in the Far-North. All IgM positive samples were from Cameroon. In cattle, 2/5 IgM positive samples were also IgG positive, but both IgM positive samples in sheep were IgG negative. Three (42.9%) IgM positive samples were positive for viral RVFV RNA using qRT-PCR but given the high ct values, no amplicon was obtained. CONCLUSION/SIGNIFICANCE: These findings confirm the circulation of RVFV in livestock in Cameroon with prevalence rates varying by location. Despite low IgM seroprevalence rates, RVF outbreaks can occur without being noticed. Further epidemiological studies are needed to have a broad understanding of RVFV transmission in Cameroon.

SARS-CoV-2, HIV, and Mycobacterium tuberculosis triple co-infection.

Tuberculosis (TB)-related death has increased for the first time in a decade due to the coronavirus disease 2019 (COVID-19), globally. People living with HIV (PLWHIV) might be at a higher risk of developing COVID-19-related complications. Herein, we describe the first case of a patient surviving from SARS-CoV-2-TB-HIV triple co-infection in Cameroon. A 36-year-old Cameroonian woman presented at the emergency unit of the Jamot Hospital, Yaoundé with symptoms of anorexia, productive cough, weight loss, and fever. The SARS-CoV-2 rapid antigen test on nasopharyngeal sample was positive. Chest X-ray showed bilateral parenchymal and tracheal calcifications most consistent with prior pulmonary histoplasmosis, varicella, or TB. She was tested HIV positive, and the sputum sample tested positive for TB on auramine staining. TB therapy (rifampicin, isoniazid, pyrazinamide, and ethambutol) and COVID-19 treatment were initiated, and the symptoms improved after 2 weeks of treatment. The SARS-CoV-2 rapid antigen and real-time polymerase chain reaction tests were negative after 2 weeks. She was discharged home on antiretroviral therapy and TB therapy. Coinfection with both TB, HIV, and SARS-CoV-2 may be common in Cameroon but not reported. The similar clinical features of COVID-19 and TB usually lead to misdiagnosis. Early diagnosis and initiation of appropriate treatment improve outcome.

Infestation rates, seasonal distribution, and genetic diversity of ixodid ticks from livestock of various origins in two markets of Yaoundé, Cameroon.

Little is known about the impact of ticks on livestock and humans in Cameroon. This study aimed to determine the prevalence, seasonal variation, and genetic diversity of hard ticks in the country. Ticks were collected during a cross-sectional survey on domestic livestock in two markets of Yaoundé in 2019 and 2020 and identified using morphological keys, 16S ribosomal DNA, (16S rDNA), and the cytochrome c oxidase subunit 1 (Cox1) genes. The infestation rates were 39.18%, 11.53%, and 2.74% in cattle, sheep, and goats respectively. Three genera of ticks were identified, Rhipicephalus, Amblyomma, and Hyalomma comprising eleven tick species. The main species were Rhipicephalus decoloratus (30.25%), R. microplus (24.43%), and Amblyomma variegatum (12.96%). Rhipicephalus spp. (81.31%) and Amblyomma variegatum (51.54%) were abundant during the rainy season, while Hyalomma spp. (83.86%) during the dry season (p-value <0.00001). Cox1 and 16S rDNA analysis showed a high level of genetic diversity among tick species with sequences close to those observed across Africa. Phylogenetic analysis revealed that our R. microplus belong to clade A and we identified R. sanguineus s.l. as R. linnea. This study shows a high tick infestation rate in cattle, while low in small ruminants with an extensive diversity of tick species, including several known vectors of important tick-borne diseases.

Multidrug-Resistant Bacteria and Enterobacteriaceae Count in Abattoir Wastes and Its Receiving Waters in Limbe Municipality, Cameroon: Public Health Implications.

The release of untreated wastes from abattoirs into the environment and nearby water bodies poses a significant threat to public health. Such litters may contain pathogens, including antibiotic-resistant bacteria. This study investigated 80 samples collected from butchering tables, slaughter slabs, meat rinsing points, and abattoir wastes receiving water from two abattoirs (A and B). Total Enterobacteriaceae count (TEC) for each sample was determined, and Escherichia coli (E. coli), Salmonella spp., Shigella spp., and Staphylococcus aureus (S. aureus) were isolated and identified. Antimicrobial susceptibility testing was done on all bacterial isolates against nine locally used antibiotics. Overall, 118 bacterial isolates, comprising E. coli (42.5%), Salmonella spp. (27.5%), Shigella spp. (37.5%), and S. aureus (40.0%), were recovered. Of the 118 bacterial isolates, 104 (88.1%) were multidrug-resistant, including 58 (55.8%) from abattoir A and 46 (44.2%) from abattoir B; however, this difference was not statistically significant (p = 0.6837). Of the 32 S. aureus isolates, 29 (90.6%) were multidrug-resistant. All S. aureus were 100% sensitive to vancomycin, kanamycin, and amikacin. Similarly, 31 (91.2%) of the 34 E. coli isolates recovered in this study were multidrug-resistant. Salmonella spp. and Shigella spp. also showed high levels of multidrug resistance corresponding to 81.8% and 86.7%, respectively. All isolates of E. coli, Salmonella, and Shigella were 100% resistant to ampicillin and 100% sensitive to ciprofloxacin. Minimum and maximum mean values for TEC were 3.62-5.83 log CFU/mL for abattoir A and 4.08-5.56 log CFU/mL for abattoir B. The highest and lowest TEC counts were from slaughter slab and upstream water, respectively, in each abattoir. Our results indicate a predominance of multidrug-resistant bacteria in abattoir wastes and their receiving waters in the study sites. Hence, we recommend the treatment of abattoir wastes before disposal and improved hygiene and sanitation practices to enhance public health.

Evaluation of the tuberculosis control program in South West Cameroon: Factors affecting treatment outcomes.

Background: Tuberculosis (TB) has been ranked as one of the leading causes of death worldwide. In Cameroon, the National Tuberculosis Control Program aims to fight TB through the implementation of international directives (Directly Observed Treatment Short course [DOTS]). TB control program must reach global targets for detection (70%) and treatment success (85%) as stated by the United Nations Millennium Development Goals (MDGs). Implementing DOTS in Cameroon has not met the MDGs of 85% success rate. This study aimed at identifying factors affecting treatment success. Methods: A cross-sectional retrospective study was used to collect data from 895 TB registers from January 2011 to December 2012. Out of the seven treatment centers in Fako Division, three were randomly selected following stratification into government, not-for-profit and for-profit structures. Descriptive statistics were used to obtain frequencies. Binomial logistics regression was used to obtain significant values for the various factors. Multinomial logistics was used on significant factors. Results: Of the 895 registered TB patient records obtained, 416 (46.5%) patient were female and 479 (53.5%) patient were male. Characterizing TB patients, 510 (57.0%) were smear-positive pulmonary TB, 225 (25.1%) were smear-negative pulmonary TB, and 160 (17.9%) were extrapulmonary TB patients. Comparing treatment success rate (TSR) across the three centers, Baptist Hospital Mutengene had the highest value 94.97 (38%), followed by Regional Hospital Buea 83.74 (33%), and Central Clinic Tiko the least 73.13 (29%). Conclusion: Patient registration year, treatment center, TB classification, and HIV status were identified to significantly affect TSR, hence, effectiveness of the TB program.

Antibiotic Susceptibility of Non-Cholera Vibrios Isolated from Farmed and Wild Marine Fish (Argyrosomus japonicus), Implications for Public Health.

This study aimed to evaluate the antibiogram and antibiotic resistance genes (ARGs) of Vibrio isolates recovered from a marine fish (Argyrosomus japonicus) and water samples from two commercial dusky kob aquaculture farms and the Kariega estuary, South Africa, and to evaluate these findings for their public health implications. A total of 277 molecularly confirmed Vibrio isolates consisting of 126 Vibrio fluvialis, 45 Vibrio vulnificus, 30 Vibrio Parahaemolyticus, and 76 vibrios belonging to species of the genus other than Vibrio cholerae were subjected to susceptibility testing to 15 antibiotics by the disc diffusion method. Multiple antibiotic resistance index (MARI) was used to determine the antibiotic resistance-associated health risk, while polymerase chain reaction was used to evaluate the presence of 14 ARGs for nonsusceptible strains. Highest resistances were recorded to amoxicillin (76.2%), ampicillin (67.5%), erythromycin (38.3%), and doxycycline (35.0%), while susceptibilities were highest to gentamicin (100%), followed by norfloxacin (97.8%), florfenicol (90.3%), tetracycline (87.7%), and chloramphenicol (87.4%). We recorded a 58.5% multidrug resistance (resistance to ≥2 antimicrobial classes). MARI did not vary significantly between sites (p > 0.05); however, values of >0.2 were recorded in 40% (108/277) of all strains tested. ARG markers, ampC, blaOXA, tetA, tetM, dfr1, sul1, sul2, ermB, nptII, strA, and SXT integrase, were detected in one or more strains with ermB (82.5%), sul2 (53.8%), strA (44%), dfr1 (42.3%), and tetM (38.3%) being the most abundant. Healthy marine finfish (dusky kob) and their environment can serve as reservoirs for antibiotic resistant vibrios and ARGs, which could be disseminated to humans and other susceptible bacteria and this therefore becomes a public health concern.

In-vitro Assessment of the Antiproliferative and Apoptotic Potential of the Ethyl acetate Extract of Peltophorumafricanum on Different Cancer Cell Lines.

We evaluated the in-vitro antiproliferative and apoptotic potential of the ethyl acetate extract (EAE) of Peltophorum africanum, a member of the family Fabaceae (Sond) in order to validate its pharmacological use. Antiproliferation of human breast (MCF-7), colon (HT-29) and cervical (HeLa) cancer cell lines by EAE was investigated using the Cell Titer-Blue viability assay and the mechanism of action delineated using the Nucleic Acid and Protein Purification Nucleospin® Tissue Kit, Scanning Electron Microscope (SEM), propidium iodide (PI) and acridine orange (AO) double-staining techniques. We observed a significant reduction in cell viability of the MCF-7 cells from 100% (untreated) to 54.33 ± 1.84% after 72 h of treatment with 5 µg/mL of EAE (P. value < 0.05). Internucleosomal DNA of MCF-7, HT-29 and HeLa cells was randomly fragmented into an uninterrupted spectrum of sizes, complemented by the intercalation of nucleic acid-specific fluorochromes by PI and AO spotting two phases of apoptosis; early (EA) and late (LA) apoptosis. Distinctive ultramorphological changes observed included; cell shrinkage, membrane blebbing, and typical cell induced death. The ethyl acetate extract of P.africanum has the potential to induce apoptosis and is undergoing further studies in-vivo as a likely template for new anticancer therapy.

Occurrence of Virulence Genes Associated with Human Pathogenic Vibrios Isolated from Two Commercial Dusky Kob (Argyrosmus japonicus) Farms and Kareiga Estuary in the Eastern Cape Province, South Africa.

Background: Seafood-borne Vibrio infections, often linked to contaminated seafood and water, are of increasing global public health concern. The aim of this study was to evaluate the prevalence of human pathogenic vibrios and their associated virulence genes isolated from fish and water samples from 2 commercial dusky kob farms and Kareiga estuary, South Africa. Methods: A total of 200 samples including dusky kob fish (n = 120) and seawater (n = 80) were subjected to Vibrio screening on thiosulfate-citrate-bile salts-sucrose agar (TCBS). Presumptive isolates were confirmed and delineated to V. cholerae, V. parahaemolyticus, V. vulnificus, and V. fluvialis by PCR. Various pathogenic gene markers were screened: V. parahaemolyticus (trh and tdh), V. vulnificus (vcgE and vcgC) and V. fluvialis (stn, vfh,hupO, vfpA). Restriction Fragment Length Polymorphism (RFLP) of the vvhA gene of V. vulnificus strains was performed to determine the associated biotypes. Results: Total Vibrio prevalence was 59.4% (606/1020) of which V. fluvialis was the most predominant 193 (31.85%), followed by Vibrio vulnificus 74 (12.21%) and V. parahaemolyticus 33 (5.45%). No V. cholerae strain was detected. One of the V. parahaemolyticus strains possessed the trh gene 7 (9.46%) while most (91.9%; 68/74) V. vulnificus isolates were of the E-type genotype. V. fluvialis virulence genes detected were stn (13.5%), hupO (10.4%) and vfpA (1.0%). 12.16% (9/74) of V. vulnificus strains exhibited a biotype 3 RFLP pattern. Conclusions: This is the first report of potentially pathogenic vibrios from healthy marine fish in the study area, and therefore a public health concern.

Cytotoxicity of three South African medicinal plants using the Chang liver cell line.

BACKGROUND: Arctotis arctotoides, Gasteria bicolor and Pittosporum viridiflorum are commonly used in the Eastern Cape, South Africa by traditional healers for the treatment of opportunistic fungal infections in HIV/AIDS patients. Unfortunately, there is a dearth of published data regarding the toxicity of the selected plants, despite the fact that experimental screening of toxicity is crucial to guarantee the safety of the users. MATERIALS AND METHODS: Therefore, it was decided to evaluate the cytotoxicity of the hexane and acetone extracts of the medicinal plants against the Chang Liver cell line using the in vitro MTT assay. Different concentrations of the extracts were added into 24-hour cultured cells and incubated for 72 hours under specific condition (37 °C, 5% CO2). Cell survival was evaluated using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS: Depending on the dosage and duration of treatment, the cytotoxic effects of Gasteria bicolor and Pittosporum viridiflorum were considered relatively weak (but not entirely absent) and less of a toxicity risk. Arctotis arctotoides extracts were the most toxic both in terms of IC50 values as well as the steeper slope of the dose response curve. The IC50 values for the acetone and hexane extracts of this plant were 17.4 and 12.4 µg/ml respectively. CONCLUSION: These relatively low values raise concern for potential hepatotoxic effects and deserve further investigation or at least a warning to potential users.

Risk factors for wound infection in health care facilities in Buea, Cameroon: aerobic bacterial pathogens and antibiogram of isolates.

INTRODUCTION: Wound infection is a significant clinical challenge in hospitals in developing countries where proper healthcare delivery is hampered by limited resources. This study investigated the antibiotic susceptibility pattern of bacteria causing wound infection and risk factors for infection among hospitalized patients in Buea, Cameroon, to generate findings which could drive reformation of policies on infection control. METHODS: Aerobic bacteria were isolated from 212 swabs collected from patients with clinically diagnosed infected wounds. Risk factors for wound infection were investigated. Antibiotic susceptibility of isolates was determined by disk diffusion technique. The Chi-square test was employed to determine significant differences in isolation and distribution of organisms in various specimens. Differences were considered significant at P<0.05. RESULTS: Twelve bacteria species were isolated from 169 (79.7%) specimens. Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae, the predominant isolates in all wound types exhibited a high preponderance of multidrug resistant strains. High rate of infection was attributed to lack of constant water supply and breakdown of sterilization equipment during the study period. Highest diversity of pathogens occurred in open wounds. There were no significant differences (P>0.05) in isolation of pathogens with respect to age, gender and wound type. Co-existing morbidity increased risk of wound infection. Isolates were susceptible to fluoroquinolones and resistant to oxacillin. CONCLUSION: Wound infection with resistant bacteria constitutes a significant cause of morbidity in the study area. Findings reiterate the need to strengthen infection control and drug dispensing policies, and greater collaboration between microbiologists and medical practioners to stem the spread of resistant bacteria.

Genetic variants of APOC3 promoter and HLA-B genes in an HIV infected cohort in northern South Africa: a pilot study.

Metabolic disorders and hypersensitivities affect tolerability and impact adherence to highly active antiretroviral therapy (HAART). The aim of this study was to determine the prevalence of C-482T/T-455C variants in the Apolipoprotein C3 (APOC3) promoter gene and Human leukocyte antigen (HLA)-B*57:01, known to impact lipid metabolic disorders and hypersensitivity respectively; and to correlate genotypes with gender, CD4+ cell count and viral load in an HIV infected cohort in northern South Africa. Frequencies of C-482 and T-455 polymorphisms in APOC3 were determined by restriction fragment length polymorphism analysis. Allele determination for HLA-B was performed with Assign SBT software in an HLA library. Analysis of APOC3 C-482 site revealed a prevalence of 196/199 (98.5%) for CC, 1/199 (0.5%) for CT and 2/199 (1.0%) for TT genotype (p = 0.000 with 1° of freedom; χ2 = 126.551). For the T-455 site, prevalences were: 69/199 (35%) for TT and 130/199 (65%) for the CC genotype (p = 0.000 with 1° of freedom; χ2 = 199). There was no association between gender and the presence of -482 (p = 1; χ2 = 0.00001) or -455 genotypes (p = 0.1628; χ2 = 1.9842). There was no significant difference in the increase in CD4+ cell count irrespective of genotypes. Significant increases in CD4+ cell count were observed in males and females considering the -455C genotype, but not in males for the -455T genotype. Viral load decreases were significant with the -455C and -482C genotypes irrespective of gender. HLA-B*57:01 was not identified in the study cohort. The apparently high prevalence of APOC3 T-455CC genotype needs confirmation with a larger samples size and triglyceride measurements to support screening of patients to pre-empt HAART associated lipid disorders.

A comparative study of M.I.C evaluator test with the broth microdilution method for antimicrobial susceptibility testing of Enterobacter cloacae isolated from cooked food.

Agar dilution and broth microdilution are widely recommended quantitative antimicrobial susceptibility test methods, but they are tedious and time consuming to implement as routine tests in many clinical laboratories. Therefore, this study aimed at comparing the broth microdilution and the M.I.C Evaluator method which has been validated for its high accuracy and easy performance for routine diagnostic use. Twenty Enterobacter cloacae strains were isolated following microbiological procedures and confirmation of the isolates used the API 20E test. The strains were evaluated for their susceptibility to seven antimicrobials using the broth microdilution and MIC Evaluator methods. The doubling dilution difference (essential agreement) in the MIC result was derived from: log2 (MIC by BMD) -log2 (MIC by M.I.C Evaluator method). The categorical agreement, interpreted as breakpoints of sensitive and resistance strains was also noted. Categorical agreement between M.I.C Evaluator strip and broth microdilution for amoxicillin, metronidazole and erythromycin was 100%: while categorical agreement for ciprofloxacin was 90%. The essential agreement for erythromycin, ciprofloxacin and tetracycline were 90%, 70% and 15% respectively. Results indicate a high efficiency of the M.I.C Evaluator strip method in determination of minimum inhibitory concentration as compared to broth microdilution method. However, further analysis regarding the suitability of the M.I.C Evaluator for testing Enterobacter cloacae is warranted considering that no consensus guidelines exist for the use of this method with the organism.

Inhibitory and bactericidal activity of selected South African honeys and their solvent extracts against clinical isolates of Helicobacter pylori.

The growing problem of antibiotic resistance by Helicobacter pylori demands the search for novel compounds, especially from natural sources. We evaluated the anti-H. pylori activity of six local honeys at different concentrations as well as their solvent extracts by the Hole Plate diffusion method. The minimum inhibitory concentration (MIC50) of the two most active extracts of each honey was determined by the broth microdilution method; and the time kill assay of the most active extract of each honey determined by viability studies. Data were analyzed by one-way ANOVA test at 95% significance level. All the honey varieties as well as their solvent extracts demonstrated varying levels of antibacterial activity based on different mean zone diameters [16.0mm (crude) to 22.2mm (extract)] and percentage susceptibilities [73.3% (crude) to 93.3% (extract)] of the test isolates. The chloroform extracts of Pure Honey (PH) and Champagne Royal Train (CRT) recorded MIC50 ranges of 0.01-10% and 0.625-10 % (v/v) respectively; that were not significantly different (P > 0.05) from amoxicillin (0.001-1.25mg/mL), the positive control. The most potent bactericidal effect against the test isolates was obtained with 5% v/v (1/2 MIC) concentration of chloroform extract of PH from 42-72 hrs. In conclusion, these honeys and their extracts could be leads for further investigation in the discovery of new natural anti-H. pylori compounds.

The acetone extract of Sclerocarya birrea (Anacardiaceae) possesses antiproliferative and apoptotic potential against human breast cancer cell lines (MCF-7).

Interesting antimicrobial data from the stem bark of Sclerocarya birrea, which support its use in traditional medicine for the treatment of many diseases, have been delineated. The current study was aimed to further study some pharmacological and toxicological properties of the plant to scientifically justify its use. Anticancer activity of water and acetone extracts of S. birrea was evaluated on three different cell lines, HT-29, HeLa, and MCF-7 using the cell titre blue viability assay in 96-well plates. Apoptosis was evaluated using the acridine orange and propidium iodide staining method, while morphological structure of treated cells was examined using SEM. The acetone extract exhibited remarkable antiproliferative activities on MCF-7 cell lines at dose- and time-dependent manners (24 h and 48 h of incubation). The extract also exerted apoptotic programmed cell death in MCF-7 cells with significant effect on the DNA. Morphological examination also displayed apoptotic characteristics in the treated cells, including clumping, condensation, and culminating to budding of the cells to produce membrane-bound fragmentation, as well as formation of apoptotic bodies. The acetone extract of S. birrea possesses antiproliferative and apoptotic potential against MCF-7-treated cells and could be further exploited as a potential lead in anticancer therapy.

Phytochemical studies and antioxidant activity of two South African medicinal plants traditionally used for the management of opportunistic fungal infections in HIV/AIDS patients.

BACKGROUND: It has been observed that perturbations in the antioxidant defense systems, and consequently redox imbalance, are present in many tissues of HIV-infected patients. Hence, the exogenous supply of antioxidants, as natural compounds that scavenge free radicals, might represent an important additional strategy for the treatment of HIV infection. The aim of this study was therefore to analyse the phytochemical constituents and antioxidant potential of Gasteria bicolor Haw and Pittosporum viridiflorum Sims., two South African plants traditionally used for the management of opportunistic fungal infections (OFIs) in AIDS patients. METHODS: The in vitro antioxidant properties of the two plants were screened through DPPH (1,1-diphenyl-2-picrylhydrazyl), NO (nitric oxide), H2O2 (hydrogen peroxide) radical scavenging effects and reducing power assays. Phytochemical studies were done by spectrophotometric techniques. RESULTS: There were no significant differences in the flavonoid and proanthocyanidins contents between the leaves and bark extracts of Gasteria bicolor and Pittosporum viridiflorum respectively, while the total phenolic content of the bark extract of P. viridiflorum was significantly higher than that of G. bicolor leaf. The acetone extracts of both plants indicated strong antioxidant activities. CONCLUSION: The results from this study indicate that the leaves and stem extracts of Gasteria bicolor and Pittosporum viridiflorum respectively possess antioxidant properties and could serve as free radical inhibitors, acting possibly as primary antioxidants. Since reactive oxygen species are thought to be associated with the pathogenesis of AIDS, and HIV-infected individuals often have impaired antioxidant defenses, the inhibitory effect of the extracts on free radicals may partially justify the traditional use of these plants in the management of OFIs in HIV patients in South Africa.