This part of our study focuses on the quantification and identification of potentially pathogenic bacteria from wild dumps in the municipality of Ibanda. The random sampling in the wild dumps was taken according to the standard of the Quebec expertise Center of environmental analysis (CEAEQ), which makes it possible to evaluate the average contamination of the environment. Hand and equipment desinfection was carried out using ethanol (70%). The bottles were placed in an isothermal bag (±4°C) and then immediately transported to the LPVMA/UOB laboratory for further treatment. We made decimal dilutions, from 100 to a 10-3 dilution. For each dilution and culture medium, Pétri dishes were inoculated in triplicate and incubation was carried out at 37°C in a Memert incubator for 24 hours. Microsoft Excel and Past softwares were used to calculate the means of each CFUs collection and to perform the nonparametric Kruskal-Wallis test that compare the median of the data between columns. The results showed that FMAT germs were generally more frequent at all sites than Enterococci that were absent at more than half (60%) of the sites. Pseudomonas averaged 300 CFU/g10-6 at 5 out of 8 sites including DSELA, DSCA, DSMUSH, DSKM, and DSRGK. Salmonella and Shigella were present in all wild dumps with a maximum average value of 160 CFU/g10-6. Nonetheless they were poorly represented in the DSGB and DSCS sites. The DSELA site had more fecal and total coliforms than the DSKR site where they were absent. Enterococci were the most represented with 38.8% and 36.79% respectively in the DSCS and DSMUSH sites and coliforms are represented with 24.75% in the DSELA site. Yet Enterococci were absent in the DSELA, DSISP, DSRGK, DSPC, and DSKM sites where the absence of CFT was also reported. Concerning the prevalence of potentially pathogenic bacteria, Nyalukemba district was in the lead with 61.4% of Enterococci, followed by Ndendere district with 57.18% of fecal and total coliforms. The Ndendere district seems to be the most exposed to diseases potentially related to wild dumps, followed by the Panzi district depending on the prevalence of bacterial groups. On 10 sites explored, 8 genera were identified on the selective medium, namely Aeromonas, Citrobacter, Enterobacter, Escherichia, Pseudomonas, Serratia, Sphingomonas and Vibrio. The implementation of the 3Rs strategy (Reduce, Recycle, and Reuse) as well as the installation of a biomethanysation plant could reduce the consequences of waste on the population and the environment.

The objective of this research was to quantify and identify pathogenic bacteria in the wastewater of Lake Kivu and the Ruzizi River, downstream of wild dumps. Bacteria samples were taken using the 250 ml sterile plastic vials. Indeed, the whole forearm is immersed in water with the vial, open at a depth of 25 to 30 cm and it is hermetically sealed inside the water itself. The samples were transported at low temperatures in a cooler containing ice blocks to the laboratory for possible analysis. Microbiological analyses were done at the LPVMA/UOB. To arrive at a possible count of the number of colonies of bacteria, the process of the dilution technique of the samples because it allows us to reduce the bacterial flora in a sample. For each site, we inoculated on three Petri dishes according to the number of dilutions (from 100 to 10-3). All Petri dishes are incubated at 37°C for 24 hours. The number of colonies was found on the surface of all three plates averaged and expressed in colony-forming units (CFU) per ml of water. Plating on the specific media was done in test tubes using a platinum loop. The results of our analyses showed that the max/min shift of the values of variables of the physicochemical parameters according to the sampling sites did not exceed the interval of one unit: salinity (0.06-0.5), temperature (24.25-25.4°C), pH (8.5-9), dissolved O2 (57.2 - 59.8 mg/L.10-1). Regarding to the variation of CFU on the different culture media used, the analyses revealed us that the number of colonies varies according to the type of culture media, which constitutes a danger of the community health of the urban population. The studies on these bacteria resistance according to the most commonly used antibiotics are capital for a better support to the public health. It is on PCA and PA where we found the most colonies than on ECA where the CFUs are the lowest. Asignificant difference was observed between the CFU detected inthe waters of Mushununu and those detected in the waters of the Ruzizi I dam (p = 0.005), those detected in the waters from Hewa Bora and those from ELAKAT (p = 0.03) and those from Honga and ELAKAT (p = 0.041). A spatial distribution of detected genera of potentially pathogenic bacteria; including Salmonella sp, Escherichia sp, Sphingomonas sp, Pseudomonas sp, Klebsiella sp, Moraxella sp, Vibrio sp, Citrobacter sp, Enterobacter sp, and Serratia sp was observed.