Photocatalytic dye degradation and photoexcited anti-microbial activities of green zinc oxide nanoparticles synthesized via Sargassum muticum extracts

Drug-resistant superbugs (DRS) were isolated from hospital sewage waste and confirmed by a 16S rDNA molecular technique as B. filamentosus, B. flexus, P. stutzeri, and A. baumannii.

Tertiary hospital sewage as reservoir of bacteria expressing MDR phenotype in Brazil

High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.

Complete Genome Sequence of the Virulent Klebsiella pneumoniae Phage Geezett Infecting Multidrug-Resistant Clinical Strains

Geezett was isolated from hospital sewage in Hangzhou, China, and exhibits lytic activity against clinical isolates of the nosocomial pathogen Klebsiella pneumoniae . The bacteriophage is a myovirus and has a double-stranded DNA (dsDNA) genome 50,707 bp long, containing 79 open reading frames (ORFs).

Identification of a Novel bla NDM Variant, bla NDM-33, in an Escherichia coli Isolate from Hospital Wastewater in China

Our study described a novel NDM-33 variant from an E. coli strain isolated from hospital sewage, where it was associated with human disease and antibiotic exposure. Importantly, hospital sewage was increasingly considered to be related to CRE hosts.

Biological characteristics and anti-biofilm activity of a lytic phage against vancomycin-resistant Enterococcus faecium

Background and Objectives: An important leading cause of the emergence of vancomycin-resistant enterococci, especially Enterococcus faecium, is the inefficiency of antibiotics in the elimination of drug-resistant pathogens. Consequently, the need for alternative treatments is more necessary than ever. Materials and Methods: A highly effective bacteriophage against vancomycin-resistant E. faecium called vB-EfmS-S2 was isolated from hospital sewage. The biological properties of phage S2 and its effect on biofilm structures were determined. Results: Phage S2 was specifically capable of lysing a wide range of clinical E. faecium isolates. According to Electron mi- croscopy observations, the phage S2 belonged to the Siphoviridea family. Suitable pH spectra for phage survival was 5-11, at which the phage showed 100% activity. The optimal temperature for phage growth was 30-45°C, with the highest growth at 37°C. Based on one-step growth curve results, the latent period of phage S2 was 14 min with a burst size of 200 PFU/ml. The phage S2 was also able to tolerate bile at concentrations of 1 and 2% and required Mg2+ for an effective infection cycle. Biofilms were significantly inhibited and disrupted in the presence of the phage. Conclusion: According to the results, phage S2 could potentially be an alternative for the elimination and control of vancomycin-resistant E. faecium biofilm.

Biological Characteristics And Genomic Analysis of A Novel Bacteriophage BUCT609 Infecting Stenotrophomonas Maltophilia

Stenotrophomonas maltophilia is widely distributed in nature and has a high isolation rate in nosocomial infections. Due to its potential application and important role in clinical practice, the relevant studies of S.maltophilia have received much attention. S.maltophilia phage BUCT609 (GenBank: MW960043) was isolated from hospital sewage with S.maltophilia strain No. 3015 as a host. Morphologically, it can be inferred as Podoviridae phage from the result of transmission electron microscopy (TEM). The electron microscopy also shows that the phage has an isometric capsid ~50 nm in diameter. The one-step growth curve demonstrated that the incubation period of 10 min and the burst size is 382 pfu/cell when its optimal multiplicity of infection (MOI) is 0.01. Phage BUCT609 had a high survival rate at pH 3 to 10 and tolerant temperature from 4 ℃ to 55 ℃. Next-Generation Sequencing (NGS) results demonstrated that its complete genome is linear double-stranded DNA of 43145 bp in length, and the GC content is 58 %. It has very little resemblance to other phages. The BlastN analysis shows that the genome of phage BUCT609 shares 22 % homology with S.maltophilia phage Ponderosa (GenBank: MK903280.1), and it encodes 56 putative proteins, of which only 25 have annotated function. Phage BUCT609 with a relatively large burst size and excellent survival ability in a wide pH and temperature range, suggests BUCT609 is a potential alternative for multi-drug resistance S.maltophilia therapy.

A novel mobile RND-type efflux pump gene cluster, tmexC3D2-toprJ3, confers tigecycline resistance in Pseudomonas alcaligenes

Tigecycline exhibits promising activity against multidrug-resistant gram-negative bacteria (MDR-GNB). However, mobile tigecycline resistance genes, such as tmexCD-toprJ encoding RND efflux pumps, have emerged. Here, we identified a novel tmexC3D2-toprJ3 gene cluster in tigecycline- and carbapenem-nonsusceptible Pseudomonas alcaligenes isolates from hospital sewage in Japan in 2020. tmexC3D2-toprJ3 and two copies of blaIMP-1 were located on the chromosome. This suggests that diverse tmexCD-toprJ-like genes have spread among MDR-GNB worldwide and further epidemiological genomic studies are needed.

On-Site Pilot Testing of Hospital Wastewater Ozonation to Reduce Pharmaceutical Residues and Antibiotic-Resistant Bacteria

Hospital sewage constitutes an important point source for antibiotics and antibiotic-resistant bacteria due to the high antibiotic use. Antibiotic resistance can develop and cause problems in sewage systems within hospitals and municipal wastewater treatment plants, thus, interventions to treat hospital sewage on-site are important. Ozonation has proven effective in treating relatively clean wastewater, but the effect on untreated wastewater is unclear. Therefore, we piloted implementation of ozonation to treat wastewater in a tertiary hospital in Uppsala, Sweden. We measured active pharmaceutical ingredients (APIs) using liquid chromatography-mass spectrometry and antibiotic-resistant Enterobacteriaceae using selective culturing pre- and post-ozonation. Comparing low (1 m3/h) and high (2 m3/h) flow, we obtained a ‘dose-dependent’ effect of API reduction (significant reduction of 12/29 APIs using low and 2/29 APIs using high flow, and a mean reduction of antibiotics of 41% using low vs. 6% using high flow, 25% vs. 6% for all APIs). There was no significant difference in the amount of antibiotic-resistant Enterobacteiaceae pre- and post-ozonation. Our results demonstrate that ozonation of untreated wastewater can reduce API content. However, due to the moderate API decrease and numerous practical challenges in the on-site setting, this specific ozonation system is not suitable to implement at full scale in our hospital.