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Journal of Hazardous Materials Jun 2024Due to the refractory of 1 H-1,2,4-triazole (TZ), conventional anaerobic biological treatment technology is usually restricted by low removal efficiency and poor system...
Due to the refractory of 1 H-1,2,4-triazole (TZ), conventional anaerobic biological treatment technology is usually restricted by low removal efficiency and poor system stability. In this study, TZ biodegradation and nitrate reduction was coupled to improve the removal efficiency of TZ from polluted wastewater. Batch assay was performed with pure culture strain Raoultella sp. NJUST42, which was reported to have the capability to degrade TZ in our previous study. Based on batch assay result, complete removal of TZ could be achieved in the presence of nitrate, whereas only 50% of TZ could be removed in the control system. Long-term stability experiment indicated that the relative abundance of microorganisms (Bacteroidetes_vadinHA17, Georgenia, Anaerolinea, etc) was obviously enhanced under nitrate reduction condition. During long-term period, major intermediates for TZ biodegradation such as [1,2,4]Triazolidine-3,5-diol, hydrazine dibasic carboxylic acid and carbamic acid were detected. A novel TZ biotransformation approach via hydration, TZ-ring cleavage, deamination and oxidation was speculated. PICRUSt1 and KEGG pathway analyses indicated that hydration (dch), oxidation (adhD, oah, pucG, fdhA) of TZ and nitrate reduction (Nar, napA, nrfA, nirBK, norB, nosZ) were significantly enhanced in the presence of nitrate. Moreover, the significant enrichment of TCA cycle (gab, sdh, fum, etc.) indicated that carbon and energy metabolism were facilitated with the addition of nitrate, thus improved TZ catabolism. The proposed mechanism demonstrated that TZ biodegradation coupled with nitrate reduction would be a promising approach for efficient treatment of wastewater contaminated by TZ.
Topics: Triazoles; Nitrates; Water Pollutants, Chemical; Biotransformation; Biodegradation, Environmental; Oxidation-Reduction; Wastewater; Bacteria; Waste Disposal, Fluid
PubMed: 38640679
DOI: 10.1016/j.jhazmat.2024.134329 -
Frontiers in Microbiology 2024This study aimed to investigate the impact of temperature and the presence of other microorganisms on the susceptibility of STEC to biocides. Mature biofilms were formed...
This study aimed to investigate the impact of temperature and the presence of other microorganisms on the susceptibility of STEC to biocides. Mature biofilms were formed at both 10°C and 25°C. An inoculum of planktonic bacteria comprising 10 CFU/mL of spoilage bacteria and 10 CFU/mL of a single strain (O157, O111, O103, and O12) was used to form mixed biofilms. The following bacterial combinations were tested: T1: + + STEC, T2: + + STEC, and T3: + + STEC. Tested biocides included quaternary ammonium compounds (Quats), sodium hypochlorite (Shypo), sodium hydroxide (SHyd), hydrogen peroxide (HyP), and BioDestroy®-organic peroxyacetic acid (PAA). Biocides were applied to 6-day-old biofilms. Minimum Bactericidal Concentrations (MBC) and Biofilm Eradication Concentrations (BEC) were determined. Planktonic cells and single-species biofilms exhibited greater susceptibility to sanitizers ( < 0.0001). and were more susceptible than the rest of the tested bacteria (p < 0.0001). Single species biofilms formed by O111, O121, O157, and O45 showed resistance (100%) to Shypo sanitizer (200 ppm) at 25°C. From the most effective to the least effective, sanitizer performance on single-species biofilms was PAA > Quats > HyP > SHyd > Shypo. In multi-species biofilms, spoilage bacteria within T1, T2, and T3 biofilms showed elevated resistance to SHyd (30%), followed by quats (23.25%), HyP (15.41%), SHypo (9.70%), and BioDestroy® (3.42%; < 0.0001). Within T1, T2, and T3, the combined STEC strains exhibited superior survival to Quats (23.91%), followed by HyP (19.57%), SHypo (18.12%), SHyd (16.67%), and BioDestroy® (4.35%; < 0.0001). O157:H7-R508 strains were less tolerant to Quats and Shypo when combined with T2 and T3 ( < 0.0001). O157:H7 and O103:H2 strains in mixed biofilms T1, T2, and T3 exhibited higher biocide resistance than the weak biofilm former, O145:H2 ( < 0.0001). The study shows that STEC within multi-species biofilms' are more tolerant to disinfectants.
PubMed: 38633705
DOI: 10.3389/fmicb.2024.1360645 -
Foodborne Pathogens and Disease Apr 2024The global food trade provides a means of disseminating antimicrobial resistant (AMR) bacteria and genes. Using selective media, carbapenem-resistant species of...
The global food trade provides a means of disseminating antimicrobial resistant (AMR) bacteria and genes. Using selective media, carbapenem-resistant species of Enterobacterales ( sp. and sp.), were detected in a single package of imported frozen shrimp purchased from a grocery store in Ohio, USA. Polymerase chain reaction confirmed that both isolates harbored genes. Following PacBio long read sequencing, the sequences were annotated using the NCBI Prokaryotic Genome Annotation Pipeline. The genes were found in IncC plasmids, each with different antimicrobial resistance island configuration. We found that the AMR islands had close relationships with previously reported environmental, food, and clinical isolates detected in Asia and the United States, highlighting the importance of the food chain in the global dissemination of antimicrobial resistance.
PubMed: 38563789
DOI: 10.1089/fpd.2023.0161 -
Infection and Drug Resistance 2024is an emerging bacterial pathogen responsible for causing infections in both humans and animals. Unfortunately, sporadic reports of carbapenem-resistant (CRRP) have...
is an emerging bacterial pathogen responsible for causing infections in both humans and animals. Unfortunately, sporadic reports of carbapenem-resistant (CRRP) have been documented worldwide. Here we first reported the complete genome sequence of a CRRP isolate RP_3045 co-carrying and , recovered from a patient in China, and its genetic relatedness to 82 strains deposited in the NCBI GenBank database, sourced from humans, animals, and the environment. Whole-genome sequencing was performed using the Illumina NovaSeq 6000 and Oxford Nanopore MinION platforms. Phylogenetic analysis was also performed and visualized using a single nucleotide polymorphism (SNP)-based strategy. The complete genome of strain RP_3045 was determined to be 6,312,961 bp in length, comprising five contigs that included one chromosome and four plasmids. RP_3045 was found to be multidrug-resistant and harbored several antimicrobial resistance genes, including both and genes located on a single plasmid. The most closely related strain was hkcpe63, recovered from humans in Hong Kong, China, in 2014, with 506 SNP differences. strains were distributed globally and exhibited strong associations among isolates obtained from different sectors. This study provides evidence for the potential of to disseminate carbapenem resistance across different sectors, highlighting the critical need for active and continuous surveillance of CRRP.
PubMed: 38560708
DOI: 10.2147/IDR.S459649 -
BMC Infectious Diseases Mar 2024In recent years, Raoultella ornithinolytica (R. ornithinolytica) have attracted clinical attention as a new type of pathogen. A wide range of infections with these germs... (Review)
Review
BACKGROUND
In recent years, Raoultella ornithinolytica (R. ornithinolytica) have attracted clinical attention as a new type of pathogen. A wide range of infections with these germs is reported, and commonly found in urinary tract infections, respiratory infections, and bacteremia.
CASE PRESENTATION
We report the case of an elderly woman with liver abscess, choledocholithiasis and cholangitis, who developed gastric fistula and abdominal abscess after underwent choledocholithotomy, and R. ornithinolytica were isolated from the abdominal drainage fluid. The patient was treated with meropenem and levofloxacin and had a good outcome.
CONCLUSIONS
To the best of our knowledge, case of isolating R. ornithinolytica from a patient with non-viscerally abdominal abscess was extremely rare. We share a case of a woman with non-viscerally abdominal abscess secondary to postoperative gastric fistula, R. ornithinolytica was isolated from the patient's pus, and the pathogenic bacteria may originate from the gastrointestinal tract. Based on this case, We should be cautious that invasive treatment may greatly increase the probability of infection with this pathogenic bacterium.
Topics: Female; Humans; Aged; Enterobacteriaceae Infections; Gastric Fistula; Enterobacteriaceae; Postoperative Complications; Liver Abscess
PubMed: 38553710
DOI: 10.1186/s12879-024-09234-y -
Environmental Research Jun 2024To achieve rapid enrichment of the targeted hydrogen-producing bacterial population and reconstruction of the microbial community in the biological hydrogen-producing...
To achieve rapid enrichment of the targeted hydrogen-producing bacterial population and reconstruction of the microbial community in the biological hydrogen-producing reactor, the activated sludge underwent multiple pretreatments using micro-aeration, alkaline treatment, and heat treatment. The activated sludge obtained from the multiple pretreatments was inoculated into the continuous stirred tank reactor (CSTR) for continuous operations. The community structure alteration and hydrogen-producing capability of the activated sludge were analyzed throughout the operation of the reactor. We found that the primary phyla in the activated sludge population shifted to Proteobacteria, Firmicutes, and Bacteroidetes, which collectively accounted for 96.69% after undergoing several pretreatments. This suggests that the multiple pretreatments facilitated in achieving the selective enrichment of the fermentation hydrogen-producing microorganisms in the activated sludge. The CSTR start-up and continuous operation of the biological hydrogen production reactor resulted in the reactor entering a highly efficient hydrogen production stage at influent COD concentrations of 4000 mg/L and 5000 mg/L, with the highest hydrogen production rate reaching 8.19 L/d and 9.33 L/d, respectively. The main genus present during the efficient hydrogen production stage in the reactor was Ethanoligenens, accounting for up to 33% of the total population. Ethanoligenens exhibited autoaggregation capabilities and a superior capacity for hydrogen production, leading to its prevalence in the reactor and contribution to efficient hydrogen production. During high-efficiency hydrogen production, flora associated with hydrogen production exhibited up to 46.95% total relative abundance. In addition, redundancy analysis (RDA) indicated that effluent pH and COD influenced the distribution of the primary hydrogen-producing bacteria, including Ethanoligenens, Raoultella, and Pectinatus, as well as other low abundant hydrogen-producing bacteria in the activated sludge. The data indicates that the multiple pretreatments and reactor's operation has successfully enriched the hydrogen-producing genera and changed the community structure of microbial hydrogen production.
Topics: Hydrogen; Bioreactors; Sewage; Bacteria; Waste Disposal, Fluid; Fermentation; Microbiota
PubMed: 38518915
DOI: 10.1016/j.envres.2024.118725 -
The Science of the Total Environment Apr 2024Carbapenem resistance poses a significant burden on healthcare systems worldwide. Microplastics (MPs) have emerged as potential contributors to antibiotic resistance...
Carbapenem resistance poses a significant burden on healthcare systems worldwide. Microplastics (MPs) have emerged as potential contributors to antibiotic resistance spread in the environment. However, the link between MPs and carbapenem resistance remains unexplored. We investigated the prevalence of carbapenem-resistant bacteria colonizing MPs placed in a river. Three replicates of a mixture of polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET) and of PET alone were placed both upstream and downstream a wastewater treatment plant (WWTP) discharge. Carbapenem-resistant Enterobacterales (CRE) were further characterized by phenotypic tests and whole-genome sequencing. The abundance of carbapenem-resistant bacteria on MPs increased significantly downstream the WWTP. Their prevalence was higher in the MPs mixture compared to PET alone. CRE strains colonizing MPs included Klebsiella pneumoniae (n = 3), Klebsiella quasipneumoniae (n = 3), Raoultella ornithinolytica (n = 2), Enterobacter kobei (n = 1) and Citrobacter freundii (n = 1), most (n = 8) recovered after the WWTP discharge. All strains exhibited at least one of the tested virulence traits (biofilm formation at 37 °C, haemolytic activity and siderophore production), were multi-drug resistant and carried carbapenemase-encoding genes [bla (n = 5), bla (n = 2) or bla + bla (n = 3)]. Uncommon phenotypes of resistance to imipenem/relebactam (n = 3) and ceftazidime/avibactam (n = 2) were observed. Two bla-positive K. pneumoniae successfully transfer this gene trough conjugation. Genome analysis predicted all strains as human pathogens. The bla was associated with the Tn4401d transposon on a pBK30683-like plasmid in most of the isolates (n = 7). The bla was mostly linked to class 3 integrons. A K. pneumoniae strain belonging to the outbreak-causing high-risk clone ST15 carried both bla and bla. Two K. quasipneumoniae isolates carried the plasmid-mediated colistin resistance gene mcr-9. Our results underscore the role of MPs as vectors for CRE dissemination, particularly following WWTPs discharges. MPs may act as carriers, facilitating the dissemination of carbapenemase-encoding genes and potentially contributing to increased CRE incidence in the environment.
Topics: Humans; Microplastics; Plastics; beta-Lactamases; Bacterial Proteins; Anti-Bacterial Agents; Klebsiella pneumoniae; Carbapenems; Water; Microbial Sensitivity Tests
PubMed: 38423305
DOI: 10.1016/j.scitotenv.2024.171268 -
Journal of Global Antimicrobial... Jun 2024
Topics: beta-Lactamases; Enterobacteriaceae; Plasmids; Humans; Anti-Bacterial Agents; Microbial Sensitivity Tests; Enterobacteriaceae Infections
PubMed: 38408560
DOI: 10.1016/j.jgar.2024.02.010 -
Urology Case Reports Mar 2024This report documents the first case of Raoultella planticola epididymo-orchitis following campylobacter gastroenteritis in a 76-year-old male. Highlighting R....
This report documents the first case of Raoultella planticola epididymo-orchitis following campylobacter gastroenteritis in a 76-year-old male. Highlighting R. planticola's expanded pathogenic potential beyond common urinary tract infections, this case emphasizes its clinical significance in atypical genitourinary presentations, particularly in individuals with pre-existing conditions like diabetes mellitus and renal failure. Despite intrinsic ampicillin resistance, targeted ciprofloxacin treatment proved effective. This case underscores the necessity for broad diagnostic considerations and tailored antibiotic therapy in managing complex infections, advocating for increased awareness of emerging resistant uropathogens in clinical practice.
PubMed: 38404681
DOI: 10.1016/j.eucr.2024.102684 -
BMC Infectious Diseases Feb 2024In Kenya, diarrhoeal disease is the third leading cause of child mortality after malaria and pneumonia, accounting for nearly 100 deaths daily. We conducted a...
BACKGROUND
In Kenya, diarrhoeal disease is the third leading cause of child mortality after malaria and pneumonia, accounting for nearly 100 deaths daily. We conducted a cross-sectional study in Mukuru informal settlements to determine the bacteria associated with diarrhea and their ASTs to provide data essential for implementing appropriate intervention measures.
METHODS
Diarrheagenic children (≤ 5 years) were purposively recruited from outpatient clinics of Municipal City Council, Mukuru kwa Reuben, Medical Missionaries of Mary, and Mama Lucy Kibaki Hospital, Nairobi. A total of 219 stool samples were collected between May 2021 and August 2021. Stool culture was done on MacConkey and Salmonella Shigella agar, while the recovered bacteria were identified using VITEK®2GNID and polymerase chain reaction (PCR) used for E. coli pathotyping. Antibiotic Susceptibility Testing was done using VITEK®2AST-GN83.
RESULTS
At least one bacterial organism was recovered from each of the 213 (97%) participants, with 115 (56%) participants having only one bacterial type isolated, 90 (43%) with two types of bacteria, and 2 (1%) with three types of bacteria recovered. The most predominant bacteria recovered was 85% (93/109) non-pathogenic E.coli and 15% (16/109)of pathogenic E.coli, with 2 (1%) were Enterohemorrhagic E.coli (EHEC), 6 (3%) were Enteroaggregative E.coli (EAEC), and 8 (4%) were Enteropathogenic E.coli (EPEC). Other potentially pathogenic bacteria included Enterobacter sp (27.8%), Klebsiella sp 33(11%), and Citrobacter sp 15(4.7%). Pathogenic isolates such as Salmonella 7 (2%), Proteus mirabilis 16 (6%), Providencia alcalifaciens 1 (0.3%), and Shigella 16 (4.7%) were detected. Isolates such as Pantoea spp 2(0.67%), Raoultella planticola 1(0.33%), and Kluyvera 6(2%) rarely reported but implicated with opportunistic diarrhoeal disease were also recovered. Ampicillin, cefazolin, and sulfamethoxazole-trimethoprim were the least effective antimicrobials at 64%, 57%, and 55% resistance, respectively, while meropenem (99%), amikacin (99%), tazobactam piperacillin (96%), and cefepime (95%) were the most effective. Overall, 33(21%) of all enterics recovered were multidrug-resistant.
CONCLUSION
The study documented different bacteria potentially implicated with childhood diarrhea that were not limited to E. coli, Shigella, and Salmonella, as previously observed in Kenya. The strains were resistant to the commonly used antibiotics, thus narrowing the treatment options for diarrheal disease.
Topics: Child; Humans; Child, Preschool; Kenya; Cross-Sectional Studies; Diarrhea; Anti-Infective Agents; Enteropathogenic Escherichia coli; Bacteria; Salmonella; Shigella
PubMed: 38388369
DOI: 10.1186/s12879-024-09114-5