Chemical Decontamination Methods Research Articles

Enhancing bioethanol yield from food waste: Integrating decontamination strategies and enzyme dosage optimization for sustainable biofuel production

Amidst the global surge in energy demand, the public’s focus has shifted from fossil fuels to more sustainable and eco-friendly fuels like bioethanol. Thus, the prospect of producing bioethanol from food waste (FW) is gaining traction, offering a sustainable solution to both waste management and energy needs. However, increasing bioethanol yields during food waste fermentation requires an approach that addresses the variability of these heterogeneous feedstocks in terms of chemical composition, microbial contamination, enzyme dosage requirements, and high moisture content. Hence, this study evaluated thermal and chemical decontamination strategies for pre- and post-consumer food waste and minimised the exogenous enzyme dosage by applying an engineered, amylase-producing strain (Saccharomyces cerevisiae ERT12). Results show that thermal sterilisation at an elevated liquefaction temperature significantly improved ethanol yields (from pre-and post-consumer food waste) more than chemical decontamination methods. Also, key findings show that applying the amylase-secreting yeast reduced enzyme dosages by up to 33 %. During fed-batch fermentation with strain ER T12, the highest possible solids loading increased the final ethanol concentrations by 96 % (for pre-consumer FW) and 85 % (for post-consumer FW) compared to batch fermentation. Also, the pre-consumer to post-consumer FW fed-batch fermentation maintained acceptable volumetric production rates of 2.35 to 1.57 g/l.h and yielded 87.6 to 61.2 % of the theoretical maximum. Although the maximum solids loadings, ethanol titres and yields achievable in food waste fermentations were still limited by the inherent moisture contents of the feed, they demonstrated performances that may be appropriate for industrial implementation, considering the negative feedstock costs.

Effectiveness of mechanical and chemical decontamination methods for the treatment of dental implant surfaces affected by peri-implantitis: A systematic review and meta-analysis.

To assess which decontamination method(s) used for the debridement of titanium surfaces (disks and dental implants) contaminated with bacterial, most efficiently eliminate bacterial biofilms. A systematic search was conducted in four electronic databases between January 1, 2010and October 31, 2022. The search strategy followed the PICOS format and included only in vitro studies completed on either dental implant or titanium disk samples. The assessed outcome variable consisted of the most effective method(s)-chemical or mechanical- removing bacterial biofilm from titanium surfaces. A meta-analysis was conducted, and data was summarized through single- and multi-level random effects model (p < .05). The initial search resulted in 5260 articles after the removal of duplicates. After assessment by title, abstract, and full-text review, a total of 13 articles met the inclusion criteria for this review. Different decontamination methods were assessed, including both mechanical and chemical, with the most common method across studies being chlorhexidine (CHX). Significant heterogeneity was noted across the included studies. The meta-analyses only identified a significant difference in biofilm reduction when CHX treatment was compared against PBS. The remaining comparisons did not identify significant differences between the various decontamination methods. The present results do not demonstrate that one method of decontamination is superior in eliminating bacterial biofilm from titanium disk and implant surfaces.

Efficacy of a novel three-step decontamination protocol for titanium-based dental implants: An invitro and invivo study.

The aim of the study was to evaluate several mechanical and chemical decontamination methods associated with a newly introduced biofilm matrix disruption strategy for biofilm cleaning and preservation of implant surface features. Titanium (Ti) discs were obtained by additive manufacturing. Polymicrobial biofilm-covered Ti disc surfaces were decontaminated with mechanical [Ti curette, Teflon curette, Ti brush, water-air jet device, and Er:YAG laser] or chemical [iodopovidone (PVPI) 0.2% to disrupt the extracellular matrix, along with amoxicillin; minocycline; tetracycline; H2 O2 3%; chlorhexidine 0.2%; NaOCl 0.95%; hydrocarbon-oxo-borate-based antiseptic] protocols. The optimal invitro mechanical/chemical protocol was then tested in combination using an invivo biofilm model with intra-oral devices. Er:YAG laser treatment displayed optimum surface cleaning by biofilm removal with minimal deleterious damage to the surface, smaller Ti release, good corrosion stability, and improved fibroblast readhesion. NaOCl 0.95% was the most promising agent to reduce invitro and invivo biofilms and was even more effective when associated with PVPI 0.2% as a pre-treatment to disrupt the biofilm matrix. The combination of Er:YAG laser followed by PVPI 0.2% plus NaOCl 0.95% promoted efficient decontamination of rough Ti surfaces by disrupting the biofilm matrix and killing remnants of invivo biofilms formed in the mouth (the only protocol to lead to ~99% biofilm eradication). Er:YAG laser + PVPI 0.2% + NaOCl 0.95% can be a reliable decontamination protocol for Ti surfaces, eliminating microbial biofilms without damaging the implant surface.

A Comparative Investigation of Chemical Decontamination Methods for In-Situ Cleaning of Dental Implant Surfaces.

Surface chemistry evaluation is crucial in assessing the efficacy of chemical decontamination products for titanium implants. This study aimed to investigate the effectiveness of chemical decontamination solutions in cleaning a contaminated dental implant surface and to evaluate the potential of combining Pluronic gel with hydrogen peroxide (NuBone®Clean) by evaluating pellicle disruption and re-formation on implant surfaces. In addition, ensuring safety with in vitro and human testing protocols. X-ray Photoelectron Spectroscopy (XPS) was utilised for surface analysis. All the tested gels had some effect on the surface cleanness except for PrefGel®. Among the tested chemical decontamination candidates, NuBone®Clean demonstrated effectiveness in providing a cleaner titanium surface. Furthermore, none of the tested chemical agents exhibited cytotoxic effects, and the safety assessment showed no adverse events. The results of this study highlight the significance of conducting comprehensive evaluations, encompassing safety and efficacy, before introducing new chemical agents for dental treatments. The findings suggest that NuBone®Clean shows potential as a chemical decontamination solution for implant surfaces. However, further investigation through randomised clinical trials is necessary. By adhering to rigorous testing protocols, the development of safe and efficient chemical decontamination strategies can be advanced, benefiting patients and promoting progress in implant dentistry.

Thermodynamic consideration on dissolution behavior of Zn-containing oxide film during chemical decontamination in light water reactors

Occupational radiation exposure has been one of the most important issues in light water reactors. The radiation source is dominantly radioactive cobalt incorporated in oxide film on structural materials. To lower radiation intensity, zinc injection has been implemented widely in light water reactors. Application of the zinc injection leads to incorporation of zinc in the oxide film and changes in the oxide film. Chemical decontamination is applied after shutdown and removes the radioactive cobalt. When the chemical decontamination was applied to plants which experienced the zinc injection, decontamination factor was sometimes lower than before the zinc injection. Then, in the present work thermodynamic solubility of divalent cobalt and divalent zinc was calculated with a thermodynamic code, assuming typical conditions of oxidizing steps of the chemical decontamination. It has been concluded that the solubility limit of divalent cobalt is 22 to 26 times higher than that of divalent zinc under any oxidizing condition. These figures are consistent with the plant data observed during the application of the chemical decontamination. It has been concluded that the oxidizing step of the typical chemical decontamination methods are suitable condition for effective dissolution of cobalt and less effective dissolution of zinc.

Microbiological and Physical Changes Produced by Different Air–Powders on Contaminated Titanium Implant Surfaces: An In Vitro Pilot Study

Air–powder abrasive treatment has shown interesting results for dental implant treatments; however, which powder is most effective is still an open question. This in vitro pilot study aims to compare the ability of six different powders (sodium bicarbonate powder—65 µm and 40 µm; glycine powder; erythritol powder—with and without cetylpyridinium chloride and calcium carbonate) to remove biofilm from contaminated titanium discs and to evaluate the physical effects of such treatments on surface topography. Seventy-four titanium discs with two different surface roughness were treated after S. sanguinis contamination. Cleaning ability and surface changes were assessed by scanning electron and confocal laser scanning microscopy as well as profilometry. All treated surfaces showed minimal bacterial residues compared to untreated ones, regardless of the treatment provided (remaining biofilm range 11.4% to 28.4% on machined discs—range 10.7% to 18.3% on moderately rough surface discs). No relevant changes on the microscopic ultrastructure of the disc surfaces were noted. The different treatments reduced biofilm up to 89.3 and 88.6% on moderately rough and machined discs, respectively, and they all showed statistically significant superiority over calcium carbonate powder. None of the tested treatments rendered the disc surfaces biofilm-free. Therefore, combined mechanical and chemical decontamination methods are still recommended to achieve maximum biofilm removal for peri-implantitis treatment.

Effects of Chemical Decontamination Methods on the Shelf Life of Poultry Meat

Son yıllarda sosyoekonomik nedenlerden kaynaklı kanatlı eti ve ürünlerine ilgi oldukça fazladır. Kanatlı etlerinin doğal florası üretim şartlarından kaynaklı çeşitli kontaminasyonlara maruz kaldıkları için önemli miktarda mikrobiyal yüke sahiptir. Bu nedenle güvenilir gıda üretmek için kanatlı etinin korunması ve muhafazası amacıyla birçok yöntem geliştirilmektedir. Bu çalışmada kanatlı etlerinin raf ömrünü uzatabilmek için kimyasal dekontaminasyon yöntemleri incelenmiştir.

Simulating the erosion modelling of pipes used in nuclear power plants in terms of physical decontamination

Decontamination practices are based on the process of reducing the radioactivity of the contaminated equipment, which occurs during operation and after the dismantling of nuclear power plants, with appropriate methods. Radioactive contamination on or near surfaces of equipment are removed by physical and/or chemical decontamination methods. This study deals with the modeling with Computational Fluid Dynamics (CFD) for the decontamination of contaminated pipes used in nuclear power plants by the physical methods of abrasion and erosion mechanism. The micromechanical process of erosion is affected by many factors. Of these multiple factors, the most critical ones, fluid and solid particle properties, particle size and velocity effects on erosion are examined. All obtained results were compared for a particular pipe diameter and size according to maximum erosion rate values.

Evaluation of filtering facepiece respirators using chemical decontamination methods

Disposable filtering facepiece respirators (FFRs) are often recommended for use by healthcare workers and the general public for infection control. During pandemic, shortage in supply of FFRs is reported due to excessive demand. Hence, suitable decontamination methods of used FFRs are required to be identified. Various chemical decontamination methods (isopropyl alcohol (IPA), vaporized hydrogen peroxide (VHP) and detergent) have been explored in the present study. The performance of the FFRs after exposed to three types of chemical decontamination methods was evaluated based on average aerosol penetration and average filter resistance values. Face mask type N95 and KN95 with four different models were used in the study. Based on the normalized data for filter aerosol penetration of the three decontamination methods, VHP is recommended to be used for decontamination methods for FFRs. Model 3 FFRs showed good performance where less deviation in the normalized filter aerosol penetration and normalized filter air flow resistance for the three decontamination methods was observed.

Electrolyzed Oxidizing Water and Its Applications as Sanitation and Cleaning Agent

Electrolyzed oxidizing water (EOW) is one of the promising novel antimicrobial agents that have recently been proposed as the alternative to conventional decontamination methods such as heat and chemical sanitizers. Acidic EOW with pH ranging from 2 to 5 is regarded most applicable in the antimicrobial treatment of vegetables and meats. Neutral and alkaline electrolyzed water have also been explored in few studies for their applications in the food industry. Neutral electrolyzed water is proposed to solve the problems related to the storage and corrosion effect of acidic EOW. Recently, the research focus has been shifted toward the application of slightly acidic EOW as more effective with some supplemental physical and chemical treatment methods such as ultrasound and UV radiations. The different applications of electrolyzed water range from drinking water and wastewater to food, utensil, and hard surfaces. The recent studies also conclude that electrolyzed water is more effective in suspensions as compared with the food surfaces where longer retention times are required. The commercialization of EOW instruments is not adopted frequently in many countries due to the potential corrosion problems associated with acidic electrolyzed water. This review article summarizes the EOW types and possible mechanism of action as well as highlights the most recent research studies in the field of antimicrobial applications and cleaning. Electrolyzed water can replace conventional chemical decontamination methods in the industry and household. However, more research is needed to know its actual mechanism of antimicrobial action along with the primary concerns related to EOW in the processing of different food products.

Совершенствование технологии дезактивации оборудования с радиоактивным загрязнением

This article analyzes the data on chemical decontamination methods dealing with radioactively contaminated surfaces. It considers the composition of solutions most commonly used for decontamination purposes. Numerical data are presented to illustrate the effectiveness of various decontamination methods. The paper considers an experiment on the decontamination of stainless steel samples with water following a cavitation treatment. The study reveals a dependence between the decontamination efficiency and the treatment time of the contaminated surface with a decontamination solution based on cavitation-activated water, which appears to be comparable with the results of the one involving an alkaline solution.

Antimicrobial Photodynamic Therapy (aPDT) for decontamination of high-speed handpieces: A comparative study.

Cross-transmission is a major concern in dental offices. Various disinfection methods have been frequently used to reduce its incidence. Standard procedures include decontamination and sterilization. Traditional decontamination methods include: Alcohol 70 % and chlorhexidine digluconate, however, antimicrobial photodynamic therapy (aPDT) could be added as an option. The objective was to evaluate the effectiveness of aPDT on decontamination of high-speed handpieces, contaminated by Staphylococcus aureus (SA) and Escherichia coli (EC), and compare it to autoclave sterilized and to conventional chemical decontamination methods. Sterilized, SA and EC contaminated high-speed handpieces were divided in 7 groups: G1- sterilized in an autoclave. G2- contaminated untreated control. G3- contaminated and decontaminated using Alcohol 70 %. G4- contaminated and decontaminated using chlorhexidine digluconate 2%. G5- contaminated and laser treated. G6- contaminated and photosensitizer treated. G7- contaminated and photodynamic therapy. The groups G3, G4, G7 did not show bacterial growth, G5 and G6 showed bacterial growth similar to G2. The study did not find SA or EC sensible to laser irradiation only, differently from some authors and did not consider biofilm in our experiments. Our experiment showed that, laser and photosensitizer isolated were not effective to inhibit Staphylococcus aureus (SA) and Escherichia coli (EC) growth, but when associated in aPDT technique, can be compared to chemical disinfection agents that are traditionally used and effective against this pathogen.

Improving the efficiency of fixed radionuclides’ removal by chemical decontamination of surfaces in situ

The article presents the results of work aimed at improving of chemical decontamination methods. A brief description of existing chemical decontamination technologies used to remove radioactive contamination (RC) from walls, floors and external surfaces of equipment without dismantling, i.e., in situ, is given. A vector of research aimed at improving the efficiency of fixed RC’s removal is also determined. The first aim of this work is to improve the decontaminating properties of removable polymer coatings used in practice. The following domestic products were chosen as study objects: compositions presented under trademarks VA, VL; and also special formulation ZPS-1M. Modifications of these compounds performed in SPSIT in some cases made it possible to significantly increase the decontamination factors (DF). The best results were obtained for VL compositions: it was found that due to certain additives it is possible to increase the DF for metal surfaces by a factor of 5–35 over the base product. Along with film-forming decontaminating compositions, an alternative patented technique has been developed in SPSIT. The main feature of this technique is usage of sorbent-based composite covering material previously saturated by decontaminating solution. New technique allows to achieve far higher decontamination factors (150–500) when fixed RC is removed from metal surfaces. In addition, it can be applied to polymer and other non-metal materials. One of the main advantages of given technique is a drastic (11–16 times) reduction of time required for carrying out decontamination operations. The obtained results may be useful for further research in this area. Thus, research performed allows to come up with general conclusion: there are possibilities to efficiently remove fixed RC from surfaces using rather simple chemical means. That, in its turn, could be a rational alternative to high-priced robotic decontaminating systems.

Toxins in broilers, infectious diseases in cats, and environmental conditions for welfare of pigs

In a current research, OLIVEIRA et al. (2018) presented a review article on the importance of mycotoxins in poultry production, especially for broilers. They evidenced some mycotoxins are harmful to human and animal health and may be an obstacle to the poultry economy due to food contamination. The most observed effects are generally the immunosuppression, hepatotoxicity and nephrotoxicity, such as decreased performance and production gains. For contamination control, it is required the adoption of suitable agricultural practices to prevent the growth of fungi, by using biological, physical and/or chemical decontamination methods, although the physical process with adsorbents mixed with the feed is more widely used. Due to the importance of mycotoxins for poultry production, it is also necessary to adopt measures to avoid contamination, besides developing a program of control and production of toxins and antifungal growth.BIEZUS et al. (2018) investigated the occurrence of infectious diseases in cats to identify the main clinical signs presented for each of them. Authors found 75% of viral infectious diseases, 12.5% of bacterial infectious diseases, 9.4% of fungal infectious diseases, 3.1% of protozoan infectious diseases. Among the most frequent infectious diseases were feline leukemia virus (39.4%) and clinical manifestations were found to be anemia (50,00%), leukemia (33.3%) and lymphoma (16.7). Authors concluded that unvaccinated male cats with free access to the street and direct contact with other felines were more numerous among the patients, which shows the close relationship of the lack of basic health care of these animals with the occurrence of the infectious diseases in the species.SANTOS et al. (2018) stated environmental modifiers, such as the use of water depths, are often used to produce pigs in order to improve welfare conditions and consequently production. So, they studied the effect of the environment on the weight gain and the behavior of pigs with and without access to the water. In general, they found the highest demand for water occurred during the afternoon due to the higher temperature in relation to the morning. In addition, the animals showed lower average daily weight gain at higher temperatures. Finally, authors concluded the water supply does not influence on the animals' weight gain, however it provides better welfare conditions.

Micotoxinas na produção de frangos de corte

The occurrence of mycotoxins has become a problem to be discussed, due to its harmfulness to humans and animal’s health, and may be an obstacle to the poultry economy. Mycotoxins are toxic metabolites produced by certain species of fungi and may contaminate food. Aflatoxins are mainly produced by Aspergillus flavus and Aspergillus parasiticus, and B1, B2, G1 and G2 are its best known types. Fumonisin, with its B1, B2 or B3 types, are produced by Fusarium, while ochratoxin A is produced by Penicillium and Aspergillus. The main trichothecenes mycotoxins are T-2 toxin, deoxynivalenol and diacetoxyscirpenol. Zearalenone, produced by different species of Fusarium fungi affects chickens only when they are exposed to extremely high levels of contamination. Generally, immunosuppression, hepatotoxicity and nephrotoxicity as a decrease in performance and production gains are the most observed effects. There are several laboratory methods that can be used for the determination of mycotoxins. In order to control the contamination, it is necessary to adopt proper farming practices which prevent fungi growth. Once grains and feed are contaminated, biological, physical and/or chemical decontamination methods may be employed, although the physical process with adsorbents mixed to the feed is more widely used. Due to the importance of mycotoxins to poultry production, it is necessary to adopt measures to prevent contamination, and also develop a control and an anti-fungal growth and toxin production program by reviewing the critical points favorable to the emergence of toxin-producing fungi.

Filter quality of electret masks in filtering 14.6–594 nm aerosol particles: Effects of five decontamination methods

This study investigates the effects of five decontamination methods on the filter quality (qf) of three commercially available electret masks—N95, Gauze and Spunlace nonwoven masks. Newly developed evaluation methods, the overall filter quality (qf,o) and the qf ratio were applied to evaluate the effectiveness of decontamination methods for respirators. A scanning mobility particle sizer is utilized to measure the concentration of polydispersed particles with diameter 14.6–594 nm. The penetration of particles and pressure drop (Δp) through the mask are used to determine qf and qf,o. Experimental results reveal that the most penetrating particle size (MPS) for the pre-decontaminated N95, Gauze and Spunlace masks were 118 nm, 461 nm and 279 nm, respectively, and the respective penetration rates were 2.6%, 23.2% and 70.0%. The Δp through the pretreated N95 masks was 9.2 mm H2O at the breathing flow rate of heavy-duty workers, exceeding the Δp values obtained through Gauze and Spunlace masks. Decontamination increased the sizes of the most penetrating particles, changing the qf values of all of the masks: qf fell as particle size increased because the penetration increased. Bleach increased the Δp of N95, but destroyed the Gauze mask. However, the use of an autoclave reduces the Δp values of both the N95 and the Gauze mask. Neither the rice cooker nor ethanol altered the Δp of the Gauze mask. Chemical decontamination methods reduced the qf,o values for the three electret masks. The value of qf,o for PM0.1 exceeded that for PM0.1–0.6, because particles smaller than 100 nm had lower penetration, resulting in a better qf for a given pressure drop. The values of qf,o, particularly for PM0.1, reveal that for the tested treatments and masks, physical decontamination methods are less destructive to the filter than chemical methods. Nevertheless, when purchasing new or reusing FFRs, penetration should be regarded as the priority.

Neutral electrolyzed water (NEW), chlorine dioxide, organic acid based product, and ultraviolet-C for inactivation of microbes in fresh-cut vegetable washing waters

The effect of decontamination methods on fresh-cut vegetable washing waters was evaluated. NEW, ClO2, organic acid-based product FPW, and UV-C were tested with and without an interfering carrot juice of 1% (IS), on Yersinia enterocolitica and Yersinia pseudotuberculosis, Escherichia coli, and yeast Candida lambica. The use of ClO2 (50 ppm active chlorine) resulted in >4 log reduction of Y. enterocolitica, Y. pseudotuberculosis, E. coli and >3 log reduction of C. lambica. The antibacterial effect of NEW was less effective in the presence of IS when compared with ClO2. The inactivation of C. lambica by FPW reached a maximum of 2.8 log cfu/mL (concentration 0.125%), but the antimicrobial effect was delayed by the IS. The effect of FPW on E. coli was significantly reduced by 1% IS. The inactivation of E. coli and C. lambica with UV-C IS decreased the inactivation and lengthened its time. Filtration improved the effect of UV-C inactivation. Practical applications When chemical decontamination methods were used in fresh-cut vegetable processing, the presence of organic matter in process water increased the reaction times and the need for higher concentrations of the chemical decontamination and the time of physical decontamination. Yersinia required longer inactivation times than E. coli. When UV-C is used for decontamination of process waters, waters should be filtered to enhance the disinfection efficacy.

Systemic cost-effectiveness analysis of food hazard reduction – Campylobacter in Danish broiler supply

An integrated microbiological–economic framework for policy support is developed to determine the cost-effectiveness of alternative intervention methods and strategies to reduce the risk of Campylobacter in broilers. Four interventions at the farm level and four interventions at the processing stage are considered. Cost analyses are conducted for different risk reduction targets and for three alternative scenarios concerning the acceptable range of interventions. Results demonstrate that using a system-wide policy approach to risk reduction can be more cost-effective than a policy focusing purely on farm-level interventions. Allowing for chemical decontamination methods may enhance cost-effectiveness of intervention strategies further.

Nanocellulose fibers for biosorption of cadmium, nickel, and lead ions from aqueous solution

Nanocellulose fibers were prepared using physico-chemical treatment of rice straw, characterized and explored for the remediation of some toxic metals from wastewater. Nanocellulose fibers were found to have long rod-like elongated nano fibrillated morphology with average grain size 6 nm. The prepared nanocellulose fibers (0.5 g) in batch experiments showed removal efficiency of 9.7 mg/g Cd (II), 9.42 mg/g Pb(II), and 8.55 mg/g Ni (II) ions from 25 mg/l of metal solution. The sorption process fitted well to both Freundlich and Langmuir isotherms [(R2) Cd (II): 0.92, 0.95; Pb(II): 0.94, 0.97 and Ni (II): 0.97, 0.98]. The regeneration studies signify that nanocellulose fibers can be successively used up to three cycles of regeneration. Nanotech reinforcement to native cellulose significantly enhanced metal removal efficiency compared to rice straw and cellulose fibers, provides new avenues as cost effective, environment-friendly green remediation or can be used as a pre-treatment step prior to chemical decontamination methods for toxic metals.

Comparison of Culture Methods for Isolation of Nontuberculous Mycobacteria from Surface Waters

The environment is the likely source of most nontuberculous mycobacteria (NTM) involved in human infections, especially pulmonary, skin, and soft tissue infections. In order to measure the prevalence of NTM in different aquatic ecosystems, we tried to standardize the culture methods used for surface water testing since many procedures have been described previously. Cultivation of mycobacteria requires long-term incubation in rich media and inactivation of rapidly growing microorganisms whose growth impedes observation of mycobacterial colonies. Consequently, the two criteria used for evaluation of the methods examined were (i) the rate of inhibition of nontarget microorganisms and (ii) the efficiency of recovery of mycobacteria. We compared the competitive growth of Mycobacterium chelonae and M. avium with nontarget microorganisms on rich Middlebrook 7H11-mycobactin medium after treatment by several chemical decontamination methods that included acids, bases, detergent, or cetylpyridinium chloride (CPC) with and without an antibiotic cocktail, either PANTA (40 U/ml polymyxin, 4 microg/ml amphotericin B, 16 microg/ml nalidixic acid, 4 microg/ml trimethoprim, and 4 microg/ml azlocillin) or PANTAV (PANTA plus 10 microg/ml vancomycin). Our results showed that treatment for 30 min with CPC (final concentration, 0.05%) of water concentrated by centrifugation, followed by culture on a rich medium supplemented with PANTA, significantly decreased the growth of nontarget microorganisms (the concentrations were 6.2 +/- 0.4 log(10) CFU/liter on Middlebrook 7H11j medium and 4.2 +/- 0.2 log(10) CFU/liter on Middlebrook 7H11j medium containing PANTA [P < 0.001]), while the effect of this procedure on NTM was not as great (the concentrations of M. chelonae on the two media were 7.0 +/- 0.0 log(10) CFU/liter and 6.9 +/- 0.0 log(10) CFU/liter, respectively, and the concentrations of M. avium were 9.1 +/- 0.0 log(10) CFU/liter and 8.9 +/- 0.0 log(10) CFU/liter, respectively). We propose that this standardized culture procedure could be used for detection of NTM in aquatic samples.