Assessment of microbiological and physicochemical parameters of ground water: A case study of Gikondo industrial park, Kigali, Rwanda

The main objective of our study was to determine the physicochemical and microbiological characteristics of two water samples: river and ground water, in Gikondo industrial park, compared to the tap water. Samples were collected from the main three sources: industrial park effluent water (river water), industrial spring water and tap water. The physicochemical properties were assessed and recorded as pH (6.9-7.75, 6.00-6.20 and 6.01-6.3 for river, spring and tap water respectively), turbidity (42-92.0, 8.9-9.1 and 12.3-14.1 for river, spring and tap water respectively), chloride (Cl-) (7.1-10.5, 9.5-12.5 and 1.8-2.8 for river, spring and tap water respectively), thiocyanide (SCN-) (++++; +++; +), chemical oxygen demand (COD) (5.0-8.9, 7.4-9.6 and 11.5-13.9 for river, spring and tap water respectively), biological oxygen demand (BOD) (0.60-0.75, 1.20-1.67 and 21.24-24.73 for river, spring and tap water respectively) and dissolved oxygen DO(0.90-0.98, 1.9-2.3 and 32-34 for river, spring and tap water respectively). Microbial analysis was conducted based on different indicators such as gas formation by catalase activity, MR/VP test and Indole formation test. In all, the microbial analysis resulted in the presence of Klebsiella, Enterobacter, Staphylococcus and Escherichia coli in the industrial river water (river water), which showed a maximum pollution rate compared to the other two samples. Such results will definitely have a key role to ascertain the impact of the industrial effluent on Gikondo industrial Park area and any potential harmful and hazardous effects on aquatic organisms, humans and plants within that environment.Key Words: Industrial effluent, Gikondo industrial park, physicochemical properties, microbiologicalanalysis, water analysis

A comparative study of microbiological and physicochemical characteristics of water distributed from two water treatment plants in Rwanda

This paper presents an assessment of water quality distributed from two Rwandan Water and Sanitation Corporation ltd (WASAC) water branches: Kimisagara WASAC water treatment plant and Kizanye WASAC station in Kigali-Rwanda. Water samples collected from those two WASAC water stations were assessed for both microbiological and physicochemical quality (temperature, odor, color and pH) using standard methods. A total of 32 samples were obtained from those stations. At the first sampling, 9 samples from homes supplied by Kizanye water station and 1 sample from its source were analyzed. Following their physicochemical records, their pH values (at 25°C) ranged from 6.61 to 7.01, temperatures ranging from 28 to 30°C, while their turbidity ranged from 1.34 to 4.9 NTU. The MPN count ranges from 0.9 to 14 MPN/100 ml. whereas regarding their microbiological assessment, fecal coliform counts on EMB agar plate ranged between 3.3×102 and 11.8×102 cfu/ml. The 9 samples from homes supplied by Kimisagara water treatment plant and 1 sample on its source were analyzed. Result of physicochemical analysis from Kimisagara plant showed that pH ranged from 7.53 to 7.00 while   temperature and turbidity values ranged from 25 to 28°C and 0.70 to 14.09°C respectively. The MPN count ranges from 1.1 to 17 MPN/100 ml. The fecal coliform counts on EMB agar plate ranged between 0 to 17.8×102 cfu/ml. Specific bacteria were isolated and then identified as Escherchia coli, Enterobacter aerogenes and Klebsiella species. Although Kimisagara and Kizanye water sources meet physicochemical and microbiological standard parameters, almost 50% of their destinations were found falling out of these standard parameters. Thus, as recommendation to WASAC authority, there is a need for improvement in the water management strategy for better water quality especially along the distribution network.Keywords: Microbiological analysis, physicochemical analysis, coliforms, Most Probable Number, water treatment, WASA

Global diversity and antimicrobial resistance of typhoid fever pathogens: Insights from a meta-analysis of 13,000 Salmonella Typhi genomes

Background: The Global Typhoid Genomics Consortium was established to bring together the typhoid research community to aggregate and analyse Salmonella enterica serovar Typhi (Typhi) genomic data to inform public health action. This analysis, which marks 22 years since the publication of the first Typhi genome, represents the largest Typhi genome sequence collection to date (n=13,000). Methods: This is a meta-analysis of global genotype and antimicrobial resistance (AMR) determinants extracted from previously sequenced genome data and analysed using consistent methods implemented in open analysis platforms GenoTyphi and Pathogenwatch. Results: Compared with previous global snapshots, the data highlight that genotype 4.3.1 (H58) has not spread beyond Asia and Eastern/Southern Africa; in other regions, distinct genotypes dominate and have independently evolved AMR. Data gaps remain in many parts of the world, and we show the potential of travel-associated sequences to provide informal ‘sentinel’ surveillance for such locations. The data indicate that ciprofloxacin non-susceptibility (>1 resistance determinant) is widespread across geographies and genotypes, with high-level ciprofloxacin resistance (=3 determinants) reaching 20% prevalence in South Asia. Extensively drug-resistant (XDR) typhoid has becomedominant in Pakistan (70% in 2020) but has not yet become established elsewhere. Ceftriaxone resistance has emerged in eight non-XDR genotypes, including a ciprofloxacin-resistant lineage (4.3.1.2.1) in India. Azithromycin resistance mutations were detected at low prevalence in South Asia, including in two common ciprofloxacin-resistant genotypes. Conclusions: The consortium’s aim is to encourage continued data sharing and collaboration to monitor the emergence and global spread of AMR Typhi, and to inform decision-making around the introduction of typhoid conjugate vaccines (TCVs) and other prevention and control strategies