scholarly journals Retention in Treated Wastewater Affects Survival and Deposition of Staphylococcus aureus and Escherichia coli in Sand Columns

2015 ◽  
Vol 81 (6) ◽  
pp. 2199-2205 ◽  
Author(s):  
Jiuyi Li ◽  
Xiaokang Zhao ◽  
Xiujun Tian ◽  
Jin Li ◽  
Jelmer Sjollema ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Wastewater Treatment ◽  
Pathogenic Bacteria ◽  
Treated Wastewater ◽  
Growth Media ◽  
Surface Charges ◽  
Content Type ◽  
Treatment Facilities ◽  
The Impact

ABSTRACTThe fate and transport of pathogenic bacteria from wastewater treatment facilities in the Earth's subsurface have attracted extensive concern over recent decades, while the impact of treated-wastewater chemistry on bacterial viability and transport behavior remains unclear. The influence of retention time in effluent from a full-scale municipal wastewater treatment plant on the survival and deposition ofStaphylococcus aureusandEscherichia colistrains in sand columns was investigated in this paper. In comparison to the bacteria cultivated in nutrient-rich growth media, retention in treated wastewater significantly reduced the viability of all strains. Bacterial surface properties, e.g., zeta potential, hydrophobicity, and surface charges, varied dramatically in treated wastewater, though no universal trend was found for different strains. Retention in treated wastewater effluent resulted in changes in bacterial deposition in sand columns. Longer retention periods in treated wastewater decreased bacterial deposition rates for the strains evaluated and elevated the transport potential in sand columns. We suggest that the wastewater quality should be taken into account in estimating the fate of pathogenic bacteria discharged from wastewater treatment facilities and the risks they pose in the aquatic environment.

scholarly journals Biological and Physicochemical Wastewater Treatment Processes Reduce the Prevalence of Virulent Escherichia coli

2012 ◽  
Vol 79 (3) ◽  
pp. 835-844 ◽  
Author(s):  
Dominic Frigon ◽  
Basanta Kumar Biswal ◽  
Alberto Mazza ◽  
Luke Masson ◽  
Ronald Gehr
Keyword(s):  
Escherichia Coli ◽  
Wastewater Treatment ◽  
Pathogenic Bacteria ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Freshwater Environment ◽  
Content Type ◽  
E Coli ◽  
Treatment Processes ◽  
The Impact

ABSTRACTEffluents discharged from wastewater treatment plants are possible sources of pathogenic bacteria, includingEscherichia coli, in the freshwater environment, and determining the possible selection of pathogens is important. This study evaluated the impact of activated sludge and physicochemical wastewater treatment processes on the prevalence of potentially virulentE. coli. A total of 719E. coliisolates collected from four municipal plants in Québec before and after treatment were characterized by using a customized DNA microarray to determine the impact of treatment processes on the frequency of specific pathotypes and virulence genes. The percentages of potentially pathogenicE. coliisolates in the plant influents varied between 26 and 51%, and in the effluents, the percentages were 14 to 31%, for a reduction observed at all plants ranging between 14 and 45%. Pathotypes associated with extraintestinal pathogenicE. coli(ExPEC) were the most abundant at three of the four plants and represented 24% of all isolates, while intestinal pathogenicE. colipathotypes (IPEC) represented 10% of the isolates. At the plant where ExPEC isolates were not the most abundant, a large number of isolates were classified as both ExPEC and IPEC; overall, 6% of the isolates were classified in both groups, with the majority being from the same plant. The reduction of the proportion of pathogenicE. colicould not be explained by the preferential loss of one virulence gene or one type of virulence factor; however, the quinolone resistance gene (qnrS) appears to enhance the loss of virulence genes, suggesting a mechanism involving the loss of pathogenicity islands.

scholarly journals Evidence of Naturalized Stress-Tolerant Strains of Escherichia coli in Municipal Wastewater Treatment Plants

2016 ◽  
Vol 82 (18) ◽  
pp. 5505-5518 ◽  
Author(s):  
Shuai Zhi ◽  
Graham Banting ◽  
Qiaozhi Li ◽  
Thomas A. Edge ◽  
Edward Topp ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Wastewater Treatment ◽  
Intergenic Region ◽  
Municipal Wastewater ◽  
Treated Wastewater ◽  
Content Type ◽  
E Coli ◽  
Biomarker Pattern ◽  
Biomarker Analysis ◽  
Pcr Targeting

ABSTRACTEscherichia colihas been proposed to have two habitats—the intestines of mammals/birds and the nonhost environment. Our goal was to assess whether certain strains ofE. colihave evolved toward adaptation and survival in wastewater. Raw sewage samples from different treatment plants were subjected to chlorine stress, and ∼59% of the survivingE. colistrains were found to contain a genetic insertion element (IS30) located within theuspC-flhDCintergenic region. The positional location of the IS30element was not observed across a library of 845E. coliisolates collected from various animal hosts or within GenBank or whole-genome reference databases for human and animalE. coliisolates (n= 1,177). Phylogenetics clustered the IS30element-containing wastewaterE. coliisolates into a distinct clade, and biomarker analysis revealed that these wastewater isolates contained a single nucleotide polymorphism (SNP) biomarker pattern that was specific for wastewater. These isolates belonged to phylogroup A, possessed generalized stress response (RpoS) activity, and carried the locus of heat resistance, features likely relevant to nonhost environmental survival. Isolates were screened for 28 virulence genes but carried only thefimHmarker. Our data suggest that wastewater contains a naturalized resident population ofE. coli. We developed an endpoint PCR targeting the IS30element within theuspC-flhDCintergenic region, and all raw sewage samples (n= 21) were positive for this marker. Conversely, the prevalence of this marker inE. coli-positive surface and groundwater samples was low (≤5%). This simple PCR assay may represent a convenient microbial source-tracking tool for identification of water samples affected by municipal wastewater.IMPORTANCEThe results of this study demonstrate that some strains ofE. coliappear to have evolved to become naturalized populations in the wastewater environment and possess a number of stress-related genetic elements likely important for survival in this nonhost environment. The presence of non-host-adapted strains in wastewater challenges our understanding of usingE. colias a microbial indicator of wastewater treatment performance, suggesting that theE. colistrains present in human and animal feces may be very different from those found in treated wastewater.

scholarly journals Topical Antimicrobial Treatments Can Elicit Shifts to Resident Skin Bacterial Communities and Reduce Colonization by Staphylococcus aureus Competitors

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Adam J. SanMiguel ◽  
Jacquelyn S. Meisel ◽  
Joseph Horwinski ◽  
Qi Zheng ◽  
Elizabeth A. Grice
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Communities ◽  
Pathogenic Bacteria ◽  
Skin Surface ◽  
Skin Microbiome ◽  
Antimicrobial Drugs ◽  
Bacterial Populations ◽  
Content Type ◽  
Topical Antibiotics ◽  
The Impact

ABSTRACT The skin microbiome is a complex ecosystem with important implications for cutaneous health and disease. Topical antibiotics and antiseptics are often employed to preserve the balance of this population and inhibit colonization by more pathogenic bacteria. However, despite their widespread use, the impact of these interventions on broader microbial communities remains poorly understood. Here, we report the longitudinal effects of topical antibiotics and antiseptics on skin bacterial communities and their role in Staphylococcus aureus colonization resistance. In response to antibiotics, cutaneous populations exhibited an immediate shift in bacterial residents, an effect that persisted for multiple days posttreatment. By contrast, antiseptics elicited only minor changes to skin bacterial populations, with few changes to the underlying microbiota. While variable in scope, both antibiotics and antiseptics were found to decrease colonization by commensal Staphylococcus spp. by sequencing- and culture-based methods, an effect which was highly dependent on baseline levels of Staphylococcus. Because Staphylococcus residents have been shown to compete with the skin pathogen S. aureus, we also tested whether treatment could influence S. aureus levels at the skin surface. We found that treated mice were more susceptible to exogenous association with S. aureus and that precolonization with the same Staphylococcus residents that were previously disrupted by treatment reduced S. aureus levels by over 100-fold. In all, the results of this study indicate that antimicrobial drugs can alter skin bacterial residents and that these alterations can have critical implications for cutaneous host defense.

scholarly journals The Behavior of Staphylococcus aureus Dual-Species Biofilms Treated with Bacteriophage phiIPLA-RODI Depends on the Accompanying Microorganism

2016 ◽  
Vol 83 (3) ◽  
Author(s):  
Silvia González ◽  
Lucía Fernández ◽  
Ana Belén Campelo ◽  
Diana Gutiérrez ◽  
Beatriz Martínez ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Laser Scanning ◽  
Pathogenic Bacteria ◽  
Real Life ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Mixed Species ◽  
Promising Alternative ◽  
Content Type ◽  
The Impact

ABSTRACT The use of bacteriophages as antimicrobials against pathogenic bacteria offers a promising alternative to traditional antibiotics and disinfectants. Significantly, phages may help to remove biofilms, which are notoriously resistant to commonly used eradication methods. However, the successful development of novel antibiofilm strategies must take into account that real-life biofilms usually consist of mixed-species populations. Within this context, this study aimed to explore the effectiveness of bacteriophage-based sanitation procedures for removing polymicrobial biofilms from food industry surfaces. We treated dual-species biofilms formed by the food pathogenic bacterium Staphylococcus aureus in combination with Lactobacillus plantarum, Enterococcus faecium, or Lactobacillus pentosus with the staphylococcal phage phiIPLA-RODI. Our results suggest that the impact of bacteriophage treatment on S. aureus mixed-species biofilms varies depending on the accompanying species and the infection conditions. For instance, short treatments (4 h) with a phage suspension under nutrient-limiting conditions reduced the number of S. aureus cells in 5-h biofilms by ∼1 log unit without releasing the nonsusceptible species. In contrast, longer infection periods (18 h) with no nutrient limitation increased the killing of S. aureus cells by the phage (decrease of up to 2.9 log units). However, in some cases, these conditions promoted the growth of the accompanying species. For example, the L. plantarum cell count in the treated sample was up to 2.3 log units higher than that in the untreated control. Furthermore, phage propagation inside dual-species biofilms also depended greatly on the accompanying species, with the highest rate detected in biofilms formed by S. aureus-L. pentosus. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) also showed changes in the three-dimensional structures of the mixed-species biofilms after phage treatment. Altogether, the results presented here highlight the need to study the impact of phage therapy on microbial communities that reflect a more realistic setting. IMPORTANCE Biofilms represent a major source of contamination in industrial and hospital settings. Therefore, developing efficient strategies to combat bacterial biofilms is of the utmost importance from medical and economic perspectives. Bacteriophages have shown potential as novel antibiofilm agents, but further research is still required to fully understand the interactions between phages and biofilm-embedded bacteria. The results presented in this study contribute to achieving a better understanding of such interactions in a more realistic context, considering that most biofilms in the environment consist of mixed-species populations.

scholarly journals Exogenous Alginate Protects Staphylococcus aureus from Killing by Pseudomonas aeruginosa

2019 ◽  
Vol 202 (8) ◽  
Author(s):  
Courtney E. Price ◽  
Dustin G. Brown ◽  
Dominique H. Limoli ◽  
Vanessa V. Phelan ◽  
George A. O’Toole
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Physical Space ◽  
Late Time ◽  
Protective Effects ◽  
Content Type ◽  
Alginate Production ◽  
The Impact

ABSTRACT Cystic fibrosis (CF) patients chronically infected with both Pseudomonas aeruginosa and Staphylococcus aureus have worse health outcomes than patients who are monoinfected with either P. aeruginosa or S. aureus. We showed previously that mucoid strains of P. aeruginosa can coexist with S. aureus in vitro due to the transcriptional downregulation of several toxic exoproducts typically produced by P. aeruginosa, including siderophores, rhamnolipids, and HQNO (2-heptyl-4-hydroxyquinoline N-oxide). Here, we demonstrate that exogenous alginate protects S. aureus from P. aeruginosa in both planktonic and biofilm coculture models under a variety of nutritional conditions. S. aureus protection in the presence of exogenous alginate is due to the transcriptional downregulation of pvdA, a gene required for the production of the iron-scavenging siderophore pyoverdine as well as the downregulation of the PQS (Pseudomonas quinolone signal) (2-heptyl-3,4-dihydroxyquinoline) quorum sensing system. The impact of exogenous alginate is independent of endogenous alginate production. We further demonstrate that coculture of mucoid P. aeruginosa with nonmucoid P. aeruginosa strains can mitigate the killing of S. aureus by the nonmucoid strain of P. aeruginosa, indicating that the mechanism that we describe here may function in vivo in the context of mixed infections. Finally, we investigated a panel of mucoid clinical isolates that retain the ability to kill S. aureus at late time points and show that each strain has a unique expression profile, indicating that mucoid isolates can overcome the S. aureus-protective effects of mucoidy in a strain-specific manner. IMPORTANCE CF patients are chronically infected by polymicrobial communities. The two dominant bacterial pathogens that infect the lungs of CF patients are P. aeruginosa and S. aureus, with ∼30% of patients coinfected by both species. Such coinfected individuals have worse outcomes than monoinfected patients, and both species persist within the same physical space. A variety of host and environmental factors have been demonstrated to promote P. aeruginosa-S. aureus coexistence, despite evidence that P. aeruginosa kills S. aureus when these organisms are cocultured in vitro. Thus, a better understanding of P. aeruginosa-S. aureus interactions, particularly mechanisms by which these microorganisms are able to coexist in proximal physical space, will lead to better-informed treatments for chronic polymicrobial infections.

scholarly journals Staphylococcus aureus Serves as an Iron Source for Pseudomonas aeruginosa during In Vivo Coculture

2005 ◽  
Vol 187 (2) ◽  
pp. 554-566 ◽  
Author(s):  
Lauren M. Mashburn ◽  
Amy M. Jett ◽  
Darrin R. Akins ◽  
Marvin Whiteley
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Iron Acquisition ◽  
Low Oxygen ◽  
Dialysis Membrane ◽  
Opportunistic Human Pathogen ◽  
The Impact

ABSTRACT Pseudomonas aeruginosa is a gram-negative opportunistic human pathogen often infecting the lungs of individuals with the heritable disease cystic fibrosis and the peritoneum of individuals undergoing continuous ambulatory peritoneal dialysis. Often these infections are not caused by colonization with P. aeruginosa alone but instead by a consortium of pathogenic bacteria. Little is known about growth and persistence of P. aeruginosa in vivo, and less is known about the impact of coinfecting bacteria on P. aeruginosa pathogenesis and physiology. In this study, a rat dialysis membrane peritoneal model was used to evaluate the in vivo transcriptome of P. aeruginosa in monoculture and in coculture with Staphylococcus aureus. Monoculture results indicate that approximately 5% of all P. aeruginosa genes are differentially regulated during growth in vivo compared to in vitro controls. Included in this analysis are genes important for iron acquisition and growth in low-oxygen environments. The presence of S. aureus caused decreased transcription of P. aeruginosa iron-regulated genes during in vivo coculture, indicating that the presence of S. aureus increases usable iron for P. aeruginosa in this environment. We propose a model where P. aeruginosa lyses S. aureus and uses released iron for growth in low-iron environments.

scholarly journals Identification and antibiogram study of bacterial species isolated from milk samples of different locations in Bangladesh

2016 ◽  
Vol 1 (3) ◽  
pp. 457-462 ◽  
Author(s):  
Md Nuruzzaman Munsi ◽  
Nathu Ram Sarker ◽  
Razia Khatun ◽  
Mohammed Khorshed Alam
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Public Health Importance ◽  
Milk Samples ◽  
First Choice

Cow’s milk containing pathogenic bacteria is an important threat to the consumers. The objectives of the present study were to identify the bacterial agents of public health importance in milk samples (n=35) of different locations and to determine their sensitivity to different antibiotics. The milk samples were collected and transported aseptically and subsequently allowed for culture in bacteriological media, Gram’s staining and biochemical tests for the identification of bacterial species. The bacteria identified were Staphylococcus aureus, Escherichia coli and Salmonella typhi, and their prevalence, in case of vendor milk specimens (n=28), were 96.43%, 53.57% and 35.71% respectively, and of brand milk specimens (n=7), were 42.86 %, 28.57% and 0%, respectively. This suggests that cautionary measures should be taken for quality milk production and consumption. The antibiotic sensitivity test was done by disc diffusion method and the average inhibition zones, in case of Staphylococcus aureus, were 32 mm for oxytetracycline, 26 mm for amoxicillin, 35 mm for ciprofloxacin, 27 mm for cefotaxime, 30 mm for ceftriaxone, 30 mm for azithromycin, and 26 mm for erythromycin; in case of Escherichia coli, were 5 mm for oxytetracycline, 9 mm for amoxicillin, 22 mm for ciprofloxacin, 30 mm for cefotaxime, 31 mm for ceftriaxone, 15 mm for azithromycin, and 0 mm for erythromycin; in case of Salmonella typhi., were 25 mm for oxytetracycline, 24 mm for amoxicillin, 38 mm for ciprofloxacin, 31 mm for cefotaxime, 34 mm for ceftriaxone, 24 mm for azithromycin, and 0 mm for erythromycin. Therefore, ciprofloxacin and ceftriaxone may be the antibiotics of first choice, and cefotaxime and azithromycin may be the second choice among the test antibiotics for the treatment of illness caused by these bacteria.Asian J. Med. Biol. Res. December 2015, 1(3): 457-462

scholarly journals Impact of Extended-Spectrum β-Lactamase Production on Treatment Outcomes of Acute Pyelonephritis Caused by Escherichia coli in Patients without Health Care-Associated Risk Factors

2015 ◽  
Vol 59 (4) ◽  
pp. 1962-1968 ◽  
Author(s):  
Sun Hee Park ◽  
Su-Mi Choi ◽  
Dong-Gun Lee ◽  
Sung-Yeon Cho ◽  
Hyo-Jin Lee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Health Care ◽  
Treatment Outcomes ◽  
Acute Pyelonephritis ◽  
Esbl Production ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
The Impact

ABSTRACTExtended-spectrum β-lactamase-producingEscherichia coli(ESBL-EC) is increasingly identified as a cause of acute pyelonephritis (APN) among patients without recent health care contact, i.e., community-associated APN. This case-control study compared 75 cases of community-associated ESBL-EC APN (CA-ESBL) to 225 controls of community-associated non-ESBL-EC APN (CA-non-ESBL) to identify the risk factors for ESBL-EC acquisition and investigate the impact of ESBL on the treatment outcomes of community-associated APN (CA-APN) caused byE. coliat a Korean hospital during 2007 to 2013. The baseline characteristics were similar between the cases and controls; the risk factors for ESBL-EC were age (>55 years), antibiotic use within the previous year, and diabetes with recurrent APN. The severity of illness did not differ between CA-ESBL and CA-non-ESBL (Acute Physiology and Chronic Health Evaluation [APACHE] II scores [mean ± standard deviation], 7.7 ± 5.9 versus 6.4 ± 5.3;P= 0.071). The proportions of clinical (odds ratio [OR], 1.76; 95% confidence interval [CI], 0.57 to 5.38;P= 0.323) and microbiological (OR, 1.16; 95% CI, 0.51 to 2.65;P= 0.730) cures were similar, although the CA-ESBL APN patients were less likely to receive appropriate antibiotics within 48 h. A multivariable Cox proportional hazards analysis of the prognostic factors for CA-APN caused byE. colishowed that ESBL production was not a significant factor for clinical (hazard ratio [HR], 0.39; 95% CI, 0.12 to 1.30;P= 0.126) or microbiological (HR, 0.49; 95% CI, 0.21 to 1.12;P= 0.091) failure. The estimates did not change after incorporating weights calculated using propensity scores for acquiring ESBL-EC. Therefore, ESBL production did not negatively affect treatment outcomes among patients with community-associatedE. coliAPN.

scholarly journals UTILIZAÇÃO DE GÁS OZÔNIO NA DESINFECÇÃO DE RESÍDUOS DE SERVIÇOS DE SAÚDE

2018 ◽  
Vol 7 (2) ◽  
pp. 125-139
Author(s):  
Thais Nogueira Gonzaga ◽  
Dora Inés Kozusny-Andreani
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Health Care Services ◽  
Pathogenic Bacteria ◽  
Ozone Treatment ◽  
Microbiological Analysis ◽  
Before And After ◽  
Staphylococcus Spp

Nesta pesquisa objetivou-se avaliar a viabilidade técnica da aplicação de ozônio como bactericida e fungicida em amostras de resíduos de serviços de saúde potencialmente infectantes. Foram determinados os     micro-organismos presentes nos resíduos gerados em um hospital particular. Para realização das análises microbiológicas e o tratamento com ozônio o material foi particulado e homogeneizado. As análises microbiológicas foram realizadas antes e após a ozonização.Para os testes de desinfecção foram retirados 10,0g de amostra que foi submetida à ozonização por 5, 10, 15, 20 e 25 minutos com doses de 140,0; 280,0; 420,0; 560,0 e 700,0mg L-1 de ozônio, respectivamente. Verificou-se presença de mesófilos totais, coliformes totais e termotolerantes, Escherichia coli, Pseudomonas aeruginosa, Proteus spp., Staphylococcus aureus, Staphylococcus spp, Candida albicans e Rhizopus spp. O ozônio foi eficiente para eliminação de todos os micro-organismos em 20 minutos; nos primeiros cinco minutos de exposição ao gás verificou-se redução superior a 98%.Palavras-chave: Bactérias patogênicas. Fungos. Ozonização. USING OZONE GAS FOR DISINFECTION OF SOLID WASTE FROM HEALTH CARE SERVICES ABSTRACT: The aim of this research was to evaluate the technical viability of the application of ozone as bactericide and fungicide in samples of potentially infectious health services residues. The microorganisms present in the waste generated in a private hospital were determined. The material was particulated and homogenized to perform the microbiological analysis and to undergo ozone treatment. Microbiological analysis was performed before and after ozonization. For the disinfection tests, 10.0g of sample were removed and submitted to ozonization for 5, 10, 15, 20 and 25 minutes with 140,0; 280,0; 420,0; 560,0 and 700,0mg doses of L-1 of ozone, respectively. It was verified the presence of total mesophiles, total and thermotolerant coliforms, Escherichia coli, Pseudomonas aeruginosa, Proteus spp., Staphylococcus aureus, Staphylococcus spp, Candida albicans and Rhizopus spp. Ozone was efficient while eliminating all microorganisms in 20 minutes; in the first five minutes of gas exposure, the reduction was greater than 98%.Keywords: Pathogenic bacteria. Fungi. Ozonization.

Sign in / Sign up

Export Citation Format

Share Document