Assessment of handwashing impact on detection of SARS-CoV-2, Staphylococcus aureus, Escherichia coli on hands in rural and urban settings of Côte d'Ivoire during COVID-19 pandemic.

BACKGROUND: Handwashing is the first line of hygiene measures and one of the oldest methods of preventing the spread of infectious diseases. Despite its efficacy in the health system, handwashing is often inadequately practiced by populations. This study aimed to assess the presence of SARS-CoV-2, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) on hands as indicators of lack of hand hygiene during COVID 19 pandemic. METHODS: A cross-sectional study was conducted in rural Taabo and urban Abidjan (Côte d'Ivoire) from January to September 2021. A total of 384 participants from 384 households were included in the study. The total households were distributed proportionally within various municipalities in the two study areas according to the number of households in each municipality, based on data of the National Institute of Statistics from the 2014 general population census. Hand swabbing of the 384 participants within households (320 in Abidjan and 64 in Taabo) was performed for the enumeration of E. coli and S aureus, using laboratory standard method and for the detection of SARS-CoV-2 by RT-qPCR. A binary logistic regression model was built with the outcome variable presence of Staphylococcus spp. on hands of respondents that was categorized into binary variables, Staphylococcus spp. (1 = presence, 0 = absence) for the Risk Ratio estimation. Place of living, sex, handwashing, education and age group were used to adjust the model to observe the effects of these explanatory variables. RESULTS: No presence of SARS-CoV-2 virus was detected on the hands of respondents in both sites. However, in urban Abidjan, only Staphylococcus spp. (Coagulase Negative Staphylococci) was found on the hands of 233 (72.8%, 95%CI: 67.7-77.4) respondents with the average load of 0.56 CFU/ Cm2 (95% CI, 0.52-0.60). Meanwhile, in rural Taabo, Staphylococcus spp. (Coagulase Negative Staphylococci) and E. coli were found on the hands of 40 (62.5%, 95%CI: 50.3-73.3) and 7 (10.9%, 95%CI: 5.4-20.9) respondents with the respective average load of 0.49 CFU/ Cm2 (95% CI, 0.39-0.59) and 0.08 CFU/ Cm2 (95% CI, 0.03-0.18). Participants living in rural Taabo were less likely to have Staphylococcus spp. on their hands (RR = 0.811; 95%IC: 0.661-0.995) compared to those living in urban Abidjan. CONCLUSIONS: No SARS-CoV-2 was detected on the hands of participants in both sites, suggesting that our study did not show direct transmission through hands. No E. coli was found in urban Abidjan while E. coli was found on the hands of participants in rural Taabo indicating poor hand washing and disinfection practices in rural Taabo. Living in urban Abidjan is statistically associated to having Staphylococcus spp. on hands. Further studies are necessary especially to understand to what extent the presence of Staphylococcus spp. on hands indicates a higher infection or fecal colonization rates in the case of E. coli.

Characterization of lactic acid bacteria isolated from a traditional Ivoirian beer process to develop starter cultures for safe sorghum-based beverages.

The present study aimed to characterize lactic acid bacteria involved in the different processing steps of tchapalo, a traditional Ivoirian beverage, for their potential application as starter cultures in food and beverages. Lactic acid bacteria (LAB) were therefore isolated and enumerated at different steps of the process on MRS and BEA agars. Of the 465 isolates, 27 produced bacteriocins that inhibit Lactobacillus delbrueckii F/31 strain. Of those, two also inhibited Listeria innocua ATCC 33090, while two others displayed inhibitory activity against L.innocua ATCC 33090, E. faecalis CIP 105042, E. faecalis ATCC 29212, Streptococcus sp. clinical LNSP, E. faecalis CIP 105042 and E. faecium ATCC 51558. The dominant species involved in tchapalo LAB fermentation, as determined by 16S rRNA gene sequencing, were Lactobacillus fermentum (64%), followed by Pediococcus acidilactici (14%). Two strains representing the two dominant species, L. fermentum S6 and P. acidilactici S7, and two potential bacteriocin producers, Weissella confusa AB3E41 and Enterococcus faecium AT1E22, were selected for further characterization. First, genome analysis showed that these strains do not display potential harmful genes such as pathogenic factors or transmissible antibiotic resistance genes. Furthermore, phylogenetic analyses were performed to assess evidence of eventual links to groups of strains with particular properties. They revealed that (i) L. fermentum S6 and P. acidilactici S7 are closely related to strains that ferment plants, (ii) E. faecium AT1E22 belongs to the environmental clade B of E. faecium, while W. confusa is quite similar to other strains also isolated from plant fermentations. Further genome analysis showed that E. faecium AT1E22 contains the Enterocin P gene probably carried by a megaplasmid, whereas no evidence of a bacteriocin gene was found in W. confusa AB3E41. The metabolic and the first step of the probiotic potentials of the different strains were analyzed. Lactobacillus fermentum S6 and P. acidilactici S7 are good candidates to develop starter cultures, and E. faecium AT1E22 should be further tested to confirm its potential as a probiotic strain in the production of sorghum wort.

Virulence factors and determination of antifungal susceptibilities of Candida species isolated from palm wine and sorghum beer.

Since it has been considered that Candida species in food or drinks may, following ingestion, enter the bloodstream and cause fungaemia, the presence of these yeast species in traditional alcoholic beverages may be of some clinical significance. Thus we attempted to assess virulence factors and antifungal susceptibility profile of Candida strains and other potential pathogenic yeasts isolated from palm wine and sorghum beer (tchapalo). Of the 23 yeast isolates from palm wine, phospholipase, esterase and haemolysin production was revealed amongst 69.6%, 65.2% and 100% isolates respectively with high activity belonging to Candida tropicalis strains. All the isolates were biofilm producers at variable degree but none showed proteinase activity. When the isolates were tested for their susceptibility to five antifungal agents, we found that ketoconazole (91.3%) followed by fluconazole (78.3%) and amphotericin B (73.9%) were the most potent agents. Of the 14 isolates from tchapalo, 57.1%, 87.5% and 57.1% exhibited phospholipase, haemolysin and esterase activity respectively. They did not also show proteinase activity while 87.5% produced biofilm. The majority of the isolates were susceptible to azoles (92.7%) and amphotericin B (85.3%) but they were 5-flucytosine resistant like palm wine strains.

Candida species in tchapalo and bangui, two traditional alcoholic beverages from Côte d'Ivoire.

The increase of infections due to non-Candida albicans species made it very necessary to conduct adequate characterization to be able to identify the species of Candida isolated from traditional fermented foods. In this study, based on their hue on Candida Chromogenic Agar medium, a total of 136 yeast strains were isolated from tchapalo and bangui. Molecular identification based on PCR-RFLP of internal transcribed spacers of rDNA (ITS) and sequencing of the ITS and the D1/D2 regions allowed us to assign these isolates to seven species: Candida tropicalis, Candida inconspicua, Candida rugosa, Saccharomyces cerevisiae, Kluyveromyces marxianus, Hanseniaspora guilliermondii, Trichosporon asahii. With the respect to each beverage, six species were found among with four species are regarded as opportunistic pathogens. From these, C. tropicalis, C. inconspicua and K. marxianus were the most commonly encountered. The enzyme activities of the potential pathogens assessed using API ZYM system showed that almost strains had esterase, esterase lipase, valine and cystine arylamidase, alpha chymotrypsin, alkaline phosphatase and naphthol phosphohydrolase activities. The activity of α-glucosidase was found only in C. tropicalis and C. inconspicua strains isolated from tchapalo while ß-glucosidase activity was found in all strains from tchapalo and only in C. inconspicua isolated from bangui.