Disinfectant-resistant bacteria in Buenos Aires city hospital wastewater

Abstract

Large quantities of disinfectants are used in hospitals, externally on human skin or to eliminate microorganisms from inanimate objects. After use, residual quantities of these products reach the wastewater, exposing the bacteria that survive in hospital wastewaters to a wide range of biocides that could act as a selective pressure for the development of resistance. Increasing attention has been directed recently to the resistance of bacteria to disinfectants. The aim of this paper was to determine the disinfectant bacterial resistance pattern of the microflora released to the urban sewer system by hospital effluents. The characterization of the waste water microflora was performed by determination of the CFU of heterotrophic bacteria, fecal indicator bacteria, Pseudomonas sp. and Staphylococcus sp., in a Buenos Aires hospital effluent. The bacterial resistance to the disinfectants more frequently used in the hospital practice, glutaraldehyde, chlorhexidine and povidoneiodine, was then evaluated. Disinfectant resistant bacterial strains were isolated and typified. Between 10 3 and 10 6 chlorexidine resistant bacteria/100 mL were isolated from the samples. Bacteria resistant to other disinfectants ranged between 10 3 and 10 4 /100 mL. The bacterial population resistant to desinfectants to was mainly composed by Enterobacteriaceae, Staphylococcus spp, and Bacillus spp, which are highly associated to nosocomial infections. The results obtained show that the hospital effluents are of importance in the bacterial resistance selection process, particularly in the case of disinfectants.

Assessment of antibiotic- and disinfectant-resistant bacteria in hospital wastewater, south Ethiopia: a cross-sectional study

“…This is in line with other studies that reported that the organism is resistant to antiseptics, disinfectants, and antibiotics and survives in the sewage system for long periods of time [5,12,13]. Contamination of rivers and lakes with this pathogen may pose a risk to public health associated with staphylococcal infection and food poisoning.…”

“…Iodine has long been considered an effective antimicrobial agent, especially when used in the form of providone-iodine [5]. This study revealed that tincture iodine-treated effluent showed no growth on nutrient agar after incubation.…”

“…This finding is in agreement with those of Favero and Drake [14], which found iodine to be an efficient microbicide compared to chlorine in swimming pools. However, Nuñez and Moretton [5] reported iodine-resistant organisms such as S. epidermidis, Bacillus spp. and Pseudomonas alcaligenes and reported that resistance increased in a nutrient-restricted environment such as the oligotropic aquatic system found in hospital waste water (HWW).…”

“…Each partial sample was collected at 8:30 a.m., 10:30 a.m., 12:30 a.m., and 2:30 a.m. in a small sterile bottle according to the method used by Nuñez and Moretton [5]. The samples were transferred into 250 mL-sized sterile bottles containing 0.2 mL of 3% w/v sodium thiosulphate and then transported within two hours in ice jackets in an ice box to the microbiology laboratory for analysis and stored in a refrigerator at 4°C until analysis.…”

Antibiotic Resistant Bacteria from Treated and Untreated Hospital Wastewater at Ayder Referral Hospital, Mekelle, North Ethiopia

“…Accordingly, hospital wastewater could increase the numbers of resistant bacteria in the recipient sewers by both mechanisms of introduction and selection pressure [5]. The release of resistant bacteria to the receiving environment can pose public health impact through, carrying transmissible gene, by acting as a vector or reservoir of resistant gene [6] [7]. The most common bacterial pathogens found in hospital wastewater are Salmonella, Shigella, S. aureus, P. aeruginosa, Vibrio, Clostridium, Yersinia, Campylobacter, Leptospira and groups of total coliforms consisting of Serratia, Enterobacter, Klebsiella, and Escherichia coli (E. coli) [8] [9].…”