Brunel M. Angounda, Serge O. Mokono, Oscar Akombo Itoua, Geneviève B. Boukatou, Boris S. Bakoua, Edwige P. Lc. Nanitelamio, Elira Dokekia A.

Hepatitis C is a global health problem and transfusion of the contaminating blood products is one of the most important mechanisms for its transmission. The aim of this study is to determine the prevalence of the HCV infection among the potential blood donors in Brazzaville, Republic of Congo. A cross-sectional study was conducted from January 2019 to December 2020 among 594 blood donors in the National Blood Transfusion Center of Brazzaville. The socio-demographic characteristics and associated risk factors were collected using a standard questionnaire. Screening of HCV was done by using the ELISA tests and P-value of less than 0.05 was considered as statistically significant. The overall prevalence of the HCV was 4.18% (95% CI:2.47-5.89). The positive cases were more prevalent among males, replacement donors and those who were less than 30 years old (68.2%). The gender of donors (P=0.04) and those with a multiple sexual partners (p = 0.019) were found to be associated with the higher risk for the HCV infection. However, there was no significant association with the history of surgery and tattooing. The present study reveals that the HCV infection is more prevalent among the blood donors in Brazzaville.

Kipsang A. K., Arodi W. O.

Ventilator support as a component of critical care is rarely utilized. It only supports the breathing system but does not change any pre-existing condition. Associated challenges include viral and bacterial infections. The prevalence of these infections is high, however most healthcare workers confuse them as bacterial infections. They impact emotional, economic and psycho-social burden on individuals, families as well as the society at large. There is no documentation of these infections in many healthcare facilities. The study aimed at assessing the prevalence rates of Influenza virus, HRV, RSV,HPIV,hMPV, Human Adenovirus and HCOV in study subjects on ventilator support as well as on critical care in the ICU.The study was done at MTRH in Uasin Gishu County. Samples were collected from January 2017 to December 2017. 200 samples of bronchoalveolar lavage were collected. The samples were then transported to KEMRI Nairobi at 2-8°C for analysis. The RNA/DNA of the viruses was detected using real time PCR. Data analysis as well as coding and entry were done using statistical package for social studies (SPSS). The results were log-transformed to obtain equal distribution. The results were also expressed as mean±standard deviation. The results were then compared with respect to whether in ICU or on mechanical ventilation as well age and gender using ANOVA with Bonferroni’s post-test using GenStat Release 14.1 (PC/Windows). Presentation of the data was done using graphs, pie charts and tables/figures. 34 cases of multiple viral infections was identified, 20 cases in MV and 14 cases in ICU. Two viruses were detected in 22 samples and three viruses in 12 samples. There was high prevalence of co-infections by Influenza A virus/PIV-3/hMPV at 4% and 3% in the ICU and those on ventilator support respectively. It is evident that these infections are common in patients in ICU and those under ventilator support at MTRH. Surveillance for viral respiratory infections should be improved in order to implement treatment and also understand seasonality of these viruses and other new respiratory viruses.

Cherinet Yigrem, Broderick Eribo, Kotu Sangre

Staphylococcus aureus is a nosocomial pathogen associated with serious community and healthcare facility acquired infections. The current study determined the occurrence and diversity of antibiotic resistance Staphylococcus aureus in leafy vegetables sold in Gondar retail markets and clinical sources from Gondar community hospital. The microbiological analyses were performed based on standard methods. The vegetable samples were plated onto plate count agar and incubated for 48h at 30°C. The aerobic plate count of the vegetable samples ranged from 5.3 to 8.3 log10 cfu/g. Among the retail vegetable samples, 31 (28.18%) of them were positive for S. aureus and the average bacterial count was 8.85 cfu/g. The prevalence of S. aureus was highest in cauliflower (13/15, 86.7%), lettuce (13/15, 86.7%), followed by spinach (7/15, 46.7%), and cabbage (2/15, 13.4%). The isolates were analysed for antibiotics susceptibility test, and most isolates (99.3%) were resistant to vancomycin, ampicillin, penicillin, erythromycin, and methicillin. All the vegetable and clinical isolates (61, 100%) were multidrug resistant. There were no significant differences in phenotypic antibiograms between vegetable and clinical isolates (P=0.097>0.05). Phylogenetic tree determined the relationship between the vegetable isolates and the clinical isolates. Macrolide and beta lactam resistant genes and virulence factors were determined among the bacterial population. Four resistant genes were analysed in ten of the antibiotic resistant isolates using colony PCR and the results revealed that 90% were encoding (erm A), 100% (ermB), 100% (erm C), and 70% (msrA) resistant determinants. The present study also determined Hla, sea, Hlb, tst, and eta virulence factors and plasmids of the bacterial isolates.

Cherinet Yigrem, Broderick Eribo, Bewketu Mengesha

Pseudomonas aeruginosa is an opportunistic pathogen commonly found in soil water and animals. These pathogenic bacteria cause severe nosocomial infections in the blood, lungs (pneumonia), or other parts of the immunocompromised people and chronic infections in cystic fibrosis patients. The aim of this study was, phenotypic characterization and molecular identification of virulence determinants in beta lactamase producing Pseudomonas aeruginosa isolated in leafy vegetables sold in Gondar retail markets and clinical sources from Gondar University Hospital. The study further aimed to identify the plasmid profile, among the bacterial population. All the isolates (n=25) were screened for biofilm formation and the result confirmed that 88% (n = 22) were biofilm producers. The antibiotics susceptibility indicated that 99.3% of the isolates were resistant. One-way ANOVA statistical test (P = 0.097 > 0.05) confirmed that there were no significant differences in antibiotic resistance between vegetables and clinical isolates. Phylogenetic tree showed similar ancestorial relationship between the vegetable and the clinical isolates. Among beta-lactamase-producing antibiotic resistant isolates (n = 25), about 88% (n = 22) were biofilm producers. Pigment production was observed in 96% (n = 24) isolates. Twelve representative isolates were screened for detection of virulence factors. Among them, 75% (n = 9) isolates were found to be LasB positive, while 100% (n = 12) were ExosA producers, 75% (n = 9) were PlcH producers and 100% (n = 12) were ToxA producers. Furthermore, all the virulence screened isolates coproduced more than two type of virulence factors. Out of the total seven screened for plasmid profile six of them were determined positive.

Tahsina Jainab, Sharmin Sultana

Proteases are one of the important groups of enzyme and are attracting global enzyme market as well as biotechnological application. In this study, the effects of cultural condition for the production protease from Bacillus circulans, isolated from dried fish were carried out. Protease activity was screened on the basis of their ability to hydrolyze skimmed milked casein, egg albumin and gelatin. Highest protease achieved from the isolate after 48 hours of incubation at 37°C with pH 8, indicating the alkaline source of enzyme. Protease production specifically depends on the medium containing glucose as a carbon source and gelatin as nitrogen source at shaking condition. During enzyme substrate reaction, maximum protease activity was achieved at 40°C and pH 7.0 in the presence of 1.5% casein used as substrate. The protease has a specific activity of 966.03 U/ml at 60% saturation of ammonium sulfate. Finally, tyrosine and cysteine were found when end product was separated by using thin layer chromatography (TLC). The result of the present study might be helpful for large-scale production of extracellular proteases.

Cherinet Yigrem, Roman Fisseha, Broderick Eribo

Klebsiella pneumoniae is a gram negative, encapsulated, non-motile bacterium that is found in the environment and has been associated with pneumonia in the alcoholic and diabetic patient population. The bacterium typically colonizes human mucosal surfaces of the oropharynx and gastrointestinal tract. Klebsiella pneumoniae is an opportunistic pathogen of medical importance. In this study a total of 27 Klebsiella pneumoniae strains were identified using standard tests. The average aerobic mesophilic bacterial count was 3.85 cfu/g and the prevalence of Klebsiella pneumoniae was highest in cauliflower and lettuce 7(25.9%), 4(14.8%) respectively followed by spinach 2(7.4%), and cabbage (2(7.4%). The antimicrobial susceptibility for 25 antibiotics indicated >98% of the Klebsiella pneumonia strains were carbapenems and β-lactam resistant. All the strains were resistant to the carbapenem drugs, (95%) Imipenem (IMP), (100%) Meropenem (MEM) (95%) Doripenem (DOR) and (87%) Ertapenem (ETP) resistance. Nine randomly selected strains were PCR screened for the presence of carbapenems genes demonstrated 9(100%) harbor resistance determinants (NDM-1), 8(88.9%) harbor resistance determinants blaOXA48, 9(100%) harbor resistance determinants blaIMP and 9(100%) harbor resistance determinants blaVIM. Furthermore, representative K. pneumonia strains profiled for plasmid DNA demonstrated that all the isolates harbor at least one plasmid.

Cherinet Yigrem, Azanaw Amare, Broderick Eribo

Acinetobacter baumannii has been an important nosocomial pathogen causing infections in immunocompromised and hospitalized patients. Multiple antibiotic resistant A. baumannii isolates are spreading and causing outbreaks globally. The present study was done to assess the prevalence of antibiotic resistance pattern of A. baumannii isolated from leafy vegetable samples from different retail markets and clinical strains collected from Gondar University Hospital. Among the 13(48.1%) vegetables and 14(51.9%) clinical isolates, the highest Acinetobacter baumannii was detected in cauliflower 6/27 (22.2%). A. baumannii isolates harbored the highest prevalence of resistance against 23 antibiotics including the following carbapenem antibiotics, meropenem (97%), imipenem (99%), ertapenem (94%), doripeneme (96.6%). Comparison of antibiotic susceptibility rate between the vegetable and clinical isolates based on one-way A nova test (P=0.93>0.05) confirmed multiple antibiotic resistance (MDR). Phylogenetic tree determined the relationship of the vegetable isolates, and the clinical isolates were coherent each other. PCR analysis result of 9 representative isolates demonstrated 100% of them harbor resistance determinants (bla OXA23), (88.8%) of them harbor resistance determinants ompA, 100% harbor resistance determinants blaOXA51 and 100% harbor resistance determinants ISAab1. Furthermore, plasmid extraction analysis for 21 representative isolates confirmed that all the isolates harbor at least one plasmid.

Olufowora Olorunleke Yinka, Akinwande Sinmiloluwa O.

In many developing countries, the role of Microbiologically Influenced Corrosion (MIC) is still limited especially in transporting pipelines because an abiotic mechanism can be invoked to explain the observed corrosion. A research on the role of microorganisms in oil transporting pipelines in Escravos gas plant, Delta state, Nigeria was conducted. The microbial count was assayed using pour plate method after which the identification of sulfate-reducing bacteria (SRB), total heterotrophic bacterial, and fungal counts were also carried out. The corrosion rates were determined by the weight loss method. The sulfate-reducing bacteria, total heterotrophic bacterial and fungal counts of the biofilm samples ranged from 4.81 × 103 to 8.56 × 103 CFU/ml, 1.22 × 104 to 2.60 × 104 CFU/ml, and 4.14 × 103 to 8.52 × 103 CFU/ml respectively. The results revealed Desulfovibrio magneticus, Desulfobulbus propionicus, and Desulfuromonas acetoxidans as sulfate-reducing bacteria present. The bacteria species identified isolates include gram-positive Bacillus subtilis, Bacillus cerus, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Halomonas subglaciescola while the identified gram negative organisms include Klebsiella oxytoca and Seratia marcescen. The fungal isolates include members of the genus Microsporum, Saccharomyces, Aspergillus, Fusarium, and Verticillium. The weight-loss method was used to determine the rate of corrosion and the mean values of corrosion rates in each pipeline ST1, ST2, ST3, ST4, and ST5 had corrosion rates of 4.47, 3.28, 4.22, 2.56, and 3.19mpy respectively. These results will therefore alert oil companies, the government, and other agencies of the possible microbiologically influenced corroding effects on pipelines.

Tchikoua Roger, Edzili Awono A. T., Youté Fanche S. A., Essia Ngang J. J.

Uncontrolled fermentation is a method of transformation which can expose food to risks of contamination by moulds and mycotoxins. Food contaminations represent a potential threat to the health of consumers. In the far North of Cameroun, Iassa obtained by spontaneous fermentation of Hibiscus sabdariffa grains belongs to this food category. This study was aimed at preserving the safety quality of Iassa against fungal growth during fermentation by using lactic acid bacteria (LAB). To carry out this work, moulds and LAB were first isolated from Iassa samples collected in the locality of Gamboura (Cameroon). This was followed by the production of Iassa at the laboratory which was inoculated with moulds and LAB, and the entire batch was left to ferment for 120 hours at 25°C. The antifungal activity of LAB and titratable acidity were evaluated during fermentation. The results showed that, Iassa is a favourable food to the development of moulds. High contamination of this product by moulds of the genus Aspergillus and Fusarium were observed. Generally, this contamination ranged from 2.9Log₁₀CFU/g to 6.9Log₁₀CFU/g. Among the isolated LAB, Lactobacillus brevis and Lactobacillus paracasei were identified as the best LAB with good antifungal activity. Lactobacillusbrevisinhibited completely the growth of Aspergillus in Iassa after 96 hours of fermentation. During this assay, a high growth of Lactobacillus brevis varying between 12.0 and 13.3 Log₁₀CFU/g was also observed. Unlike Lactobacillus brevis, Lactobacillus paracasei produced a high quantity of acidity evaluated at 0.9%. From this work, these bacteria can be used as a LAB starter to ensure safety of the Iassa against moulds after 96 hours of fermentation.

Reuben N. Okechi, Edna I. Chukwura, Christian O. Nweke

The toxicities of some metal ions (Pb²⁺, Cd²⁺, Ni²⁺, Zn²⁺, Co²⁺ as individuals and in quaternary and quinary mixtures with Sodium Dodecyl Sulfate (SDS) to Serratia marcescens (SerEW01) isolated from Otamiri river, Owerri, Imo State, Nigeria were assessed, using dehydrogenase activity as an endpoint. The EC_50S observed ranged from 0.046 ± 0.003 mM for Zn²⁺ to 2.329 ± 0.092 mM for SDS and Duncan tests indicated that the EC_50S of the toxicants were significantly different from each other. Among the individual toxicants, the increasing toxicities ranking were SDS> Pb²⁺> Ni²⁺> Co²⁺> Cd²⁺> Zn²⁺. The responses of the bacterium to the toxicities of the toxicants were dose-dependent, and the toxicants also progressively inhibited the dehydrogenase activity as the concentration increased. Fixed ratio mixtures (Arbitrary concentration ratio (ABCR) and equieffect concentration ratio (EECR) mixtures) were designed to evaluate the combined toxicities of these toxicants. All the dose-response relationships of the ABCR and EECR mixtures and the individual toxicants could be described by 2-parameter logistic function. All quaternary and quinary mixtures were strongly synergistic against the organisms. Within each mixture ratio, experimental, CA and IA-predicted EC_50S were statistically different from one another for both mixtures. The quinary mixtures were generally more toxic to the bacterium than the quaternary mixtures. Both CA and IA models greatly underestimated the toxicities of the quaternary and quinary mixtures against S. marcescens (SerEW01). The synergistic effects of the both the quaternary and quinary mixtures of the toxicants indicates potential deleterious effects of the mixtures to the aquatic bacteria of the river.