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Fang Tang - One of the best experts on this subject based on the ideXlab platform.

  • Inactivation and reactivation of Antibiotic-Resistant Bacteria during and after UV disinfection in reclaimed water
    Huan jing ke xue= Huanjing kexue, 2014
    Co-Authors: Jing-jing Huang, Fang Tang, Yu-chen Pang
    Abstract:

    Prevalence of Antibiotic-Resistant Bacteria in wastewater effluents is concerned as an emerging contaminant. To estimate inactivation and reactivation potentials of Antibiotic-Resistant Bacteria by UV disinfection, inactivation and reactivation of penicillin-, ampicillin-, cephalexin-, chloramphenicol-and rifampicin-resistant Bacteria in the secondary effluent were studied under different UV doses. The results showed that the inactivation ratios of penicillin-, ampicillin-, cephalexin-and chloramphenicol-resistant Bacteria were higher than 4-log, which was closed to that of total heterotrophic Bacteria; however, the inactivation ratio of rifampicin-resistant Bacteria was lower (3.7-log) under 20 mJ x cm(-2) UV exposure. After 22 h standing incubation, Antibiotic-Resistant Bacteria widely reactivated. The colony forming ability of Antibiotic-Resistant Bacteria was as high as 3-log when exposed to 20 mJ x cm(-2) UV light. Hence, conventional UV dose can not effectively control reactivation of Antibiotic-Resistant Bacteria in reclaimed water by UV disinfection.

  • Monitoring and evaluation of Antibiotic-Resistant Bacteria at a municipal wastewater treatment plant in China
    Environment International, 2012
    Co-Authors: Jing-jing Huang, Sun-qin Lu, Yun Lu, Hong-ying Hu, Fang Tang, Yi Li, Bin Wei
    Abstract:

    The prevalence of Antibiotic-Resistant Bacteria in municipal wastewater treatment plants (WWTPs) is becoming a concern of public health. In order to acquire information on the emission of Antibiotic-Resistant Bacteria from WWTP effluents into natural waters, both average antibiotic tolerance and concentrations of Antibiotic-Resistant Bacteria in the effluent of a WWTP in Beijing, China were investigated. A new index of IC(50)/MIC ratio (the antibiotic concentration required to inhibit 50% of total heterotrophic Bacteria compared to the highest minimum inhibitory concentration value of a group of pathogens according to a specific antibiotic, as defined by CLSI) was used to reflect the average antibiotic tolerance of total heterotrophic Bacteria in the secondary effluent. The results showed that the IC(50)/MIC ratios of heterotrophic Bacteria in the secondary effluent to penicillin, ampicillin, cephalothin, chloramphenicol and rifampicin were >2, >1, >1, and 1.08, respectively, which reflected a significantly high general level of heterotrophic Bacteria found in the secondary effluent resistant to these five antibiotics. The concentrations of penicillin-, ampicillin-, cephalothin-, and chloramphenicol-resistant Bacteria were as high as 1.5×10(4)-1.9×10(5), 1.2×10(4)-1.5×10(5), 8.9×10(3)-1.9×10(5) and 2.6×10(4)-2.0×10(5) CFU/mL, and the average percentages in relation to total heterotrophic Bacteria were 63%, 47%, 55%, and 69%, respectively. The concentrations of tetracycline- and rifampicin-resistant Bacteria were 840-6.1×10(3) and 310-6.1×10(4) CFU/mL with average percentages of 2.6% and 11%, respectively. Furthermore, our study found that five- and six-Antibiotic-Resistant Bacteria were widely distributed in four types of enteroBacteria from the secondary effluent. The presence of multiple-Antibiotic-Resistant Bacteria from effluents of WWTPs into natural waters could pose a serious problem as a secondary pollutant of drinking water.

  • Inactivation and reactivation of Antibiotic-Resistant Bacteria by chlorination in secondary effluents of a municipal wastewater treatment plant.
    Water research, 2011
    Co-Authors: Jing-jing Huang, Fang Tang
    Abstract:

    Reports state that chlorination of drinking water and wastewater affects the proportions of Antibiotic-Resistant Bacteria by potentially assisting in microbial selection. Studies on the effect of chlorination on like species of Antibiotic-Resistant Bacteria, however, have shown to be conflicting; furthermore, few studies have inspected the regrowth or reactivation of Antibiotic-Resistant Bacteria after chlorination in wastewater. To understand the risks of chlorination resulting from potentially selecting for Antibiotic-Resistant Bacteria, inactivation and reactivation rates of both total heterotrophic Bacteria and Antibiotic-Resistant Bacteria (including penicillin-, ampicillin-, tetracycline-, chloramphenicol-, and rifampicin-resistant Bacteria) were examined after chlorinating secondary effluent samples from a municipal wastewater treatment plant in this study. Our experimental results indicated similar inactivation rates of both total heterotrophic Bacteria and Antibiotic-Resistant Bacteria. Microbial community composition, however, was affected by chlorination: treating samples with 10 mg Cl(2)/L for 10 min resulted in chloramphenicol-resistant Bacteria accounting for nearly 100% of the microbial population in contrast to 78% before chlorination. This trend shows that chlorination contributes to selection of some Antibiotic-Resistant strains. Reactivation of Antibiotic-Resistant Bacteria occurred at 2.0 mg Cl(2)/L for 10 min; specifically, chloramphenicol-, ampicillin-, and penicillin-resistant Bacteria were the three prevalent groups present, and the reactivation of chloramphenicol-resistant Bacteria exceeded 50%. Regrowth and reactivation of Antibiotic-Resistant Bacteria in secondary effluents after chlorination with a long retention time could threaten public health security during wastewater reuse.

Jing-jing Huang - One of the best experts on this subject based on the ideXlab platform.

  • Inactivation and reactivation of Antibiotic-Resistant Bacteria during and after UV disinfection in reclaimed water
    Huan jing ke xue= Huanjing kexue, 2014
    Co-Authors: Jing-jing Huang, Fang Tang, Yu-chen Pang
    Abstract:

    Prevalence of Antibiotic-Resistant Bacteria in wastewater effluents is concerned as an emerging contaminant. To estimate inactivation and reactivation potentials of Antibiotic-Resistant Bacteria by UV disinfection, inactivation and reactivation of penicillin-, ampicillin-, cephalexin-, chloramphenicol-and rifampicin-resistant Bacteria in the secondary effluent were studied under different UV doses. The results showed that the inactivation ratios of penicillin-, ampicillin-, cephalexin-and chloramphenicol-resistant Bacteria were higher than 4-log, which was closed to that of total heterotrophic Bacteria; however, the inactivation ratio of rifampicin-resistant Bacteria was lower (3.7-log) under 20 mJ x cm(-2) UV exposure. After 22 h standing incubation, Antibiotic-Resistant Bacteria widely reactivated. The colony forming ability of Antibiotic-Resistant Bacteria was as high as 3-log when exposed to 20 mJ x cm(-2) UV light. Hence, conventional UV dose can not effectively control reactivation of Antibiotic-Resistant Bacteria in reclaimed water by UV disinfection.

  • Monitoring and evaluation of Antibiotic-Resistant Bacteria at a municipal wastewater treatment plant in China
    Environment International, 2012
    Co-Authors: Jing-jing Huang, Sun-qin Lu, Yun Lu, Hong-ying Hu, Fang Tang, Yi Li, Bin Wei
    Abstract:

    The prevalence of Antibiotic-Resistant Bacteria in municipal wastewater treatment plants (WWTPs) is becoming a concern of public health. In order to acquire information on the emission of Antibiotic-Resistant Bacteria from WWTP effluents into natural waters, both average antibiotic tolerance and concentrations of Antibiotic-Resistant Bacteria in the effluent of a WWTP in Beijing, China were investigated. A new index of IC(50)/MIC ratio (the antibiotic concentration required to inhibit 50% of total heterotrophic Bacteria compared to the highest minimum inhibitory concentration value of a group of pathogens according to a specific antibiotic, as defined by CLSI) was used to reflect the average antibiotic tolerance of total heterotrophic Bacteria in the secondary effluent. The results showed that the IC(50)/MIC ratios of heterotrophic Bacteria in the secondary effluent to penicillin, ampicillin, cephalothin, chloramphenicol and rifampicin were >2, >1, >1, and 1.08, respectively, which reflected a significantly high general level of heterotrophic Bacteria found in the secondary effluent resistant to these five antibiotics. The concentrations of penicillin-, ampicillin-, cephalothin-, and chloramphenicol-resistant Bacteria were as high as 1.5×10(4)-1.9×10(5), 1.2×10(4)-1.5×10(5), 8.9×10(3)-1.9×10(5) and 2.6×10(4)-2.0×10(5) CFU/mL, and the average percentages in relation to total heterotrophic Bacteria were 63%, 47%, 55%, and 69%, respectively. The concentrations of tetracycline- and rifampicin-resistant Bacteria were 840-6.1×10(3) and 310-6.1×10(4) CFU/mL with average percentages of 2.6% and 11%, respectively. Furthermore, our study found that five- and six-Antibiotic-Resistant Bacteria were widely distributed in four types of enteroBacteria from the secondary effluent. The presence of multiple-Antibiotic-Resistant Bacteria from effluents of WWTPs into natural waters could pose a serious problem as a secondary pollutant of drinking water.

  • Inactivation and reactivation of Antibiotic-Resistant Bacteria by chlorination in secondary effluents of a municipal wastewater treatment plant.
    Water research, 2011
    Co-Authors: Jing-jing Huang, Fang Tang
    Abstract:

    Reports state that chlorination of drinking water and wastewater affects the proportions of Antibiotic-Resistant Bacteria by potentially assisting in microbial selection. Studies on the effect of chlorination on like species of Antibiotic-Resistant Bacteria, however, have shown to be conflicting; furthermore, few studies have inspected the regrowth or reactivation of Antibiotic-Resistant Bacteria after chlorination in wastewater. To understand the risks of chlorination resulting from potentially selecting for Antibiotic-Resistant Bacteria, inactivation and reactivation rates of both total heterotrophic Bacteria and Antibiotic-Resistant Bacteria (including penicillin-, ampicillin-, tetracycline-, chloramphenicol-, and rifampicin-resistant Bacteria) were examined after chlorinating secondary effluent samples from a municipal wastewater treatment plant in this study. Our experimental results indicated similar inactivation rates of both total heterotrophic Bacteria and Antibiotic-Resistant Bacteria. Microbial community composition, however, was affected by chlorination: treating samples with 10 mg Cl(2)/L for 10 min resulted in chloramphenicol-resistant Bacteria accounting for nearly 100% of the microbial population in contrast to 78% before chlorination. This trend shows that chlorination contributes to selection of some Antibiotic-Resistant strains. Reactivation of Antibiotic-Resistant Bacteria occurred at 2.0 mg Cl(2)/L for 10 min; specifically, chloramphenicol-, ampicillin-, and penicillin-resistant Bacteria were the three prevalent groups present, and the reactivation of chloramphenicol-resistant Bacteria exceeded 50%. Regrowth and reactivation of Antibiotic-Resistant Bacteria in secondary effluents after chlorination with a long retention time could threaten public health security during wastewater reuse.

Diamadopoulos E Bouki C, Venieri D - One of the best experts on this subject based on the ideXlab platform.

  • Detection and fate of antibiotic resistant Bacteria in wastewater treatment plants: a review
    Ecotoxicol Environ Saf, 2013
    Co-Authors: Diamadopoulos E Bouki C, Venieri D
    Abstract:

    Antibiotics are among the most successful group of pharmaceuticals used for human and veterinary therapy. However, large amounts of antibiotics are released into municipal wastewater due to incomplete metabolism in humans or due to disposal of unused antibiotics, which finally find their ways into different natural environmental compartments. The emergence and rapid spread of antibiotic resistant Bacteria (ARB) has led to an increasing concern about the potential environmental and public health risks. ARB and antibiotic resistant genes (ARGs) have been detected extensively in wastewater samples. Available data show significantly higher proportion of antibiotic resistant Bacteria contained in raw and treated wastewater relative to surface water. According to these studies, the conditions in wastewater treatment plants (WWTPs) are favourable for the proliferation of ARB. Moreover, another concern with regards to the presence of ARB and ARGs is their effective removal from sewage. This review gives an overview of the available data on the occurrence of ARB and ARGs and their fate in WWTPs, on the biological methods dealing with the detection of Bacterial populations and their resistance genes, and highlights areas in need for further research studies

M. G. Perilli - One of the best experts on this subject based on the ideXlab platform.

  • Urban wastewater reuse: water treatment and effectiveness on Antibiotic-Resistant Bacteria abatement
    Water Resources Management IV, 2007
    Co-Authors: G. Del Re, A. Di Donato, Roberto Volpe, M. G. Perilli
    Abstract:

    In Abruzzo Region (Italy) the implementation of European Community and National regulations for urban wastewater reuse has been carried out since 2003, when the Environmental National Authority issued the D.M. 185 giving technical rules and water quality standards for three types of reuse: irrigation, civil aims and industry. Pilot plant experiences of tertiary treatments added to conventional urban wastewater treatment plants (UWWTPs) have been carried out, in order to test the suitability of different disinfection technologies to reach the standards required for an effluent to be reused. In addition other parameters affecting the quality of reclaimed water, and for which there is currently no regulation or control, have been investigated; among them, antibiotic resistant Bacteria concentration. To evaluate the extent of problems related to antibiotic resistant Bacteria and the effectiveness of tertiary treatment on their abatement level, a significant portion of the wastewater network of the city of L’Aquila (Italy) and the related wastewater treatment plant were monitored. Antibiotic resistant Bacteria content in non-treated sewage from municipal hospital and residential areas was evaluated. The UWWTP treating this sewage is of activated sludge type and is located near the Aterno River. The wastewater coming from the secondary treatment and from the tertiary treatments was analysed in order to investigate the influence on the Antibiotic-Resistant Bacteria content. An analogous investigation was carried out in the river upstream and downstream the point of discharge of the UWWTP.

Michael Millar - One of the best experts on this subject based on the ideXlab platform.

  • Perinatal vertical transmission of Antibiotic-Resistant Bacteria: a systematic review and proposed research strategy.
    BJOG : an international journal of obstetrics and gynaecology, 2014
    Co-Authors: Josephine V. Seale, Michael Millar
    Abstract:

    Background Antibiotic-Resistant Bacteria contribute to both early- and late-onset sepsis and outbreaks in neonatal intensive care units (NICUs). The extent to which vertical transmission of these resistant Bacteria contributes to colonisation or infection of vulnerable infants in NICUs is unclear. Risk factors for vertical transmission of Antibiotic-Resistant Bacteria are not well described. Objectives To identify studies describing vertical transmission of Antibiotic-Resistant Bacteria, risk factors for transmission and the impact of colonisation on neonatal outcomes. Search strategy EMBASE, CINAHL, Cochrane, PubMed, and MEDLINE databases were searched using selected terminology. Titles and abstracts were screened by two reviewers. Selected papers were reviewed in full by two individuals to ascertain whether they fulfilled the inclusion criteria. Selection criteria Any original article investigating perinatal vertical transmission of Antibiotic-Resistant Bacteria between a mother and neonate was included. Data collection and analysis Data were extracted on study design, organism, antibiotic resistance, and means of ascertaining vertical transmission. Main results Five papers out of 4839 titles fulfilled the inclusion criteria. Four studies were predominantly observational and one was a case report. Each demonstrated perinatal transmission. No study reported risk factors for the transmission of resistant Bacteria or the impact of colonisation on neonatal outcomes. Author's conclusions There is an absence of research into the perinatal transmission of resistant organisms despite the potential implications of such a situation. We outline objectives that need to be addressed in future research and describe a study design to ascertain the prevalence and risk factors for vertical transmission.

  • Carriage of Antibiotic-Resistant Bacteria by healthy children
    The Journal of antimicrobial chemotherapy, 2001
    Co-Authors: Michael Millar, Timothy R. Walsh, C. J. Linton, S. Zhang, J P Leeming, Peter M. Bennett
    Abstract:

    The frequency of carriage of Antibiotic-Resistant Bacteria in healthy 7- and 8-year-old children in Bristol was studied. Children born in Avon between 1 April 1991 and 31 December 1992, attending the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) 7 year follow-up clinic, formed the study population. Carriage was estimated using mouth and stool samples. None of 105 children on whom information was available had received tetracycline, chloramphenicol, ciprofloxacin or an extended-spectrum cephalosporin in the previous year. Staphylococcus aureus was isolated from mouthwashes from 200 (37.1%) of 539 children sampled. Six (3%) of the isolates were resistant to chloramphenicol or tetracycline and four (2%) were methicillin resistant. Haemophilus spp. were isolated from 369 (72%) of 513 samples and 63 (17%) were ampicillin resistant, 49 (13.3%) were erythromycin resistant and seven (1.9%) were tetracycline resistant. Branhamella catarrhalis was isolated from 333 (74%) of 450 samples. Twenty-eight (8.4%) were erythromycin resistant and 14 (4.2%) strains were tetracycline resistant. Group A beta-haemolytic streptococci were isolated from 17 of 507 children sampled. One (5.9%) was tetracycline resistant. Stool samples were returned from 335 (62%) of 539 children from whom they were requested. Eleven per cent of samples yielded Gram-negative bacilli with high-level resistance to chloramphenicol, which was frequently linked to resistance to ampicillin, spectinomycin and streptomycin. Isolates demonstrating resistance to the third-generation cephalosporin ceftazidime were recovered from 17 subjects (3.2%). Six (35%) of 17 isolates possessed extended-spectrum beta-lactamases. Healthy children carry Bacteria resistant to antibiotics to which children are not usually exposed. Resistance to ceftazidime, chloramphenicol and tetracycline may be co-selected by exposure to other antibiotics used in children or may be acquired from family members, pets, other children or food. These results suggest that Antibiotic-Resistant Bacteria are widely disseminated and may be acquired by children before exposure to specific selection pressure.