High Frequency of the EMRSA-15 Clone (ST22-MRSA-IV) in Hospital Wastewater

Hospital wastewaters often carry multidrug-resistant bacteria and priority pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA). Pathogens and antibiotic resistance genes present in wastewaters may reach the natural environment facilitating their spread. Thus, we aimed to isolate MRSA from wastewater of 3 hospitals located in the north of Portugal and to characterize the isolates regarding the antimicrobial resistance and genetic lineages. A total of 96 wastewater samples were collected over six months. The water was filtered, and the filtration membrane was immersed in BHI broth supplemented with 6.5% of NaCl and incubated. The inoculum was streaked in ORSAB agar plates for MRSA isolation. The isolates susceptibility testing was performed against 14 antimicrobial agents. The presence of resistance and virulence genes was accessed by PCR. Molecular typing was performed in all isolates. From the 96 samples, 28 (29.2%) were MRSA-positive. Most isolates had a multidrug-resistant profile and carried the mecA, blaZ, aac(6′)-Ie-aph(2″)-Ia, aph(3′)-IIIa, ermA, ermB, ermC, tetL, tetM, dfrA dfrG and catpC221 genes. Most of the isolates were ascribed to the immune evasion cluster (IEC) type B. The isolates belonged to ST22-IV, ST8-IV and ST105-II and spa-types t747, t1302, t19963, t6966, t020, t008 and tOur study shows that MRSA can be found over time in hospital wastewater. The wastewater treatment processes can reduce the MRSA load. The great majority of the isolates belonged to ST22 and spa-type t747 which suggests the fitness of these genetic lineages in hospital effluents.

Modelling the impact of urban and hospital wastewaters eco-exposomes on the antibiotic-resistance dynamics.

Antibiotic-resistance emergence and selection have become major public health issues globally. The presence of antibiotic resistant bacteria (ARB) in natural and anthroposophical environments threatens to compromise the sustainability of care in human and animal populations. This study was undertaken to develop a simple model formalizing the selective impact of antibiotics and pollutants on the dynamics of bacterial resistance in water and use the model to analyze longitudinal spatiotemporal data collected in hospital and urban wastewaters. Longitudinal-sampling data were collected between 2012 and 2015 in four different locations in Haute-Savoie, France: hospital and urban wastewaters, before and after water-treatment plants. Three different exposure variables: 1) heavy metals 2) antibiotics and 3) surfactants; and normalized abundance of 88 individual genes and mobile genetic elements, mostly conferring resistance to antibiotics, were simultaneously collected. A simple hypothesis-driven model describing the weekly ARB dynamics was proposed to fit available data by assuming normalized gene abundance to be proportional to ARB populations in water. Compounds impacts on the dynamics of 17 genes found in multiple sites were estimated. We found that while mercury and vancomycin had relevant effects on ARB dynamics, respectively positively affecting the dynamics of 10 and 12 identified genes, surfactants antagonistically affected genes dynamics (identified for three genes). This simple model enables analyzing the relationship between resistance-gene persistence in aquatic environments and specific compounds inherent to human activities. Applying our model to longitudinal data, we identified compounds that act as co-selectors for antibiotic resistance.

Preliminary Investigation of Microbial Community in Wastewater and Surface Waters in Sri Lanka and the Philippines

In this study, the composition and richness of bacterial communities in treated and untreated wastewater from hospitals, commercial, and non-commercial fish farming sites, sewage effluents, and surface waters, which included seawater and fresh water in Sri Lanka and the Philippines, were investigated through 16S rRNA gene amplicon sequence analysis. Firmicutes were found predominantly in Sri Lankan hospital wastewaters, while Cyanobacteria and Acidobacteria were typically detected in fish culture sites and the waste canal in Sri Lanka, respectively. The Shannon–Weaver index (SW) and number of Operational Taxonomic Units (OTUs) were higher in the Philippines than in Sri Lanka. The bacterial richness in the university non-commercial fish pond and sewage effluent displayed greater than that in hospital wastewaters. In addition, the bacterial richness was higher in the untreated wastewater compared to that in the treated wastewater in hospitals. These results indicate the differences among water types in terms of bacterial community, especially influenced by their source.

Performance evaluation of ozonation for removal of antibiotic-resistant Escherichia coli and Pseudomonas aeruginosa and genes from hospital wastewater

The performance of ozonation for the removal of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) using Escherichia coli and Pseudomonas aeruginosa carrying ARGs from hospital wastewaters was evaluated in this study. Bacterial inactivation was determined using plate count methods and real time PCR for ARG damage (Sul1, blatem, blactx, blavim and qnrS). The reduction rate of bacterial cells and ARGs was increased by different amounts of transferred ozone dose from 11 to 45 mg/L. The concentration of 108 cfu/ml bacteria was reduced to an acceptable level by ozone treatment after a 5 min contact time, Although the removal rate was much higher for concentrations of 106 cfu/ml and 104 cfu/ml bacteria. Overall, the tendency of gene reduction by ozonation from more to less was 16S rRNA > sul1 > blatem > blactx > qnrS > blavim. Given that plasmid-borne ARGs can potentially be transferred to other bacteria even after the disinfection process, our results can provide important insights into the fate of ARGs during hospital wastewater ozonation.

Occurrence and Anti-microbial Susceptibility Pattern of Extended Spectrum Beta‑Lactamase Producing Enterobacteriaceae in Waste Water Released from Governmental Hospital of Addis Ababa, Ethiopia

Background Worldwide, come out and dissemination of Extended-spectrum beta-lactamases (ESBLs) producing Enterobacteriaceae has been warning the efficacy of antibiotics to treat an infection. Hospital wastewaters were a reservoir of such kind of resistant bacteria. Currently, the predominant antibiotics used for the treatment of hospitalized patients infected by Gram negative bacteria are the 𝛽-lactam antibiotics. So it is an important source to investigate the magnitude of ESBLs producing bacteria and their antimicrobial susceptibility pattern. The aim of this study was to determine the occurrence of ESBLs producing Enterobacteriaceae (ESBLs-pE) and their antibiotic susceptibility pattern in wastewater released from five governmental hospitals in Addis Ababa, Ethiopia. Method A cross-sectional study was carried out from April 1 to May 31, 2020. A total of 100 wastewaters were collected from five governmental hospitals in Addis Ababa using a grap-sampling technique. All Enterobacteriaceae were screened for ESBLs production using cefotaxime and ceftazidime as per 29th CLSI guideline. Each screen positive for ESBLs production was confirmed by the combination disk method (CDT) and their antibiotic susceptibility pattern were done using the Kirby-Bauer disk diffusion method on Muller Hinton agar (MHA). Data were entered and summarized using SPSS version 20 software. Results Of all Enterobacteriaceae, 48.3% were confirmed ESBLs-pE. The highest ratio of ESBLs-PE was observed in adult ward (66.7%) and laundry unit effluent (58.8%). The highest ESBL producers were E. coli (21.8%) and K. pneumoniae (4.8%). The most elevated resistance level of ESBL producer were observed to cefotaxime (95.8%) and amoxacilline/clavunalate (93%). 64% of tested Enterobacteriaceae isolates were multi drug resistant (MDR). Conclusion Higher magnitude of MDR and ESBLs-pE were present in the hospital wastewater. Majority of them were in adult ward and laundry unit effluents. The most frequent ESBLs-pE was among E .coli and K. pneumoniae. Hence, Consistent infection prevention and control procedures should be in practice at each ward/unit.

Identification and characterization of vancomycin-resistant Staphylococcus aureus in hospital wastewaters: evidence of horizontal spread of antimicrobial resistance

Antibiotic resistance has become a major threat to human health around the world, but its spread through the aquatic environment has been often overlooked. This study aimed to determine the occurrence of vancomycin-resistant Staphylococcus aureus in hospital wastewaters and their transmission into public water bodies in Kerala, India. A total of 113 S. aureus were isolated from three hospital effluents in Kerala, India. Standard disc diffusion and the strip method were used for antibiotic susceptibility testing and minimum inhibitory concentration detection. Plasmid-mediated vancomycin resistance was confirmed by plasmid curing and conjugation; resistant genes were detected by the polymerase chain reaction (PCR). Nearly 76% of S. aureus isolates were resistant to β-lactams, chloramphenicol, macrolides, aminoglycosides, and glycopeptide class of antibiotics. Among the vancomycin-resistant Staphylococcus aureus (VRSA) isolates, the prevalence rates of vanA and vanB resistance-encoding genes were 46.5 and 59.3%, respectively. Through the broth mating method, vanA gene was successfully transferred from VRSA donor to vancomycin-sensitive S. aureus. The study strongly indicates the contamination of water bodies with antibiotic-resistant bacteria from hospital discharges, their dissemination and possible transfer to microbes in the aquatic environment, posing a serious threat for public health.

Appraisal on Microbiologal Qualities of Hospital Wastewaters from off a Local Government Area of Kwara State, Nigeria

Aims: This study investigates the microorganisms associated with hospital wastewaters collected from the Offa Local Government Area of Kwara State, Nigeria, during the wet and dry seasons. Study Design: This project was a cross sectional descriptive study in which subjects were hospital wastewater samples collected from the study site. Place and Duration of Study: the samples were analyzed in the department of microbiology, Federal University of Technology, Akure, Ondo State, Nigeria. Methodology: Microbiological study of one hundred and twenty-six samples of hospital wastewater collected both during wet season and dry season periods in the years 2018 – 2019 from Offa Local Government Area of Kwara State, Nigeria, was carried out using conventional and molecular techniques respectively and the Global Positioning System (GPS) of each collection site was accurately recorded. Results: The microbial load of wet season samples collected from Offa Local Government Area ranged between 7±4,00 and 150±43.59 while that of dry season samples ranged between 10±2.00 x 105 and 225±67.27 (x 105cfu/ml). The bacteria isolated from wet season samples included; Alcaligenes faecalis, A. aquatilis and Staphylococcus saprophyticus with percentage occurrences of 65.4, 19.2 and 15.4 respectively, while bacteria isolated from dry season sample were A. faecalis and S. saprophyticus with percentages occurrence of 79.17 and 20.89, respectively. Conclusion: The findings from this study showed that hospital wastewater collected during dry season period had more bacterial load than that of wet season period. The findings also confirmed A. faecalis as the most predominant and prevailing bacteria inhabiting hospital wastewater. Thus, care must be taken by avoiding hospital wastewater from getting into the municipal water supply to prevent infections associated with A. faecalis, A. aquatilis and S. saprophyticus.