Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Enterohaemorrhagic strains of Escherichia coli as a paradigm of emerging pathogens. Lessons from the large outbreak of foodborne infections centred in Germany throughout May and June of 2011

Enterohaemorrhagic strains of Escherichia coli (EHEC) are foodborne zoonotic pathogens associated with major outbreaks and sporadic cases of diarrhoea and haemorrhagic colitis or bloody diarrhea, which can progress to the hemolytic uremic syndrome (HUS). The importance of EHEC lies in the severity of HUS, which is the most frequent cause of acute renal failure in children in the Americas and Europe. It was predicted years ago that EHEC strains other than the prototypic O157H7 serotype would emerge as significant foodborne pathogens. Since then, these microorganisms have been linked to numerous outbreaks and sporadic cases of disease around the world. The incidence of these serotypes continues to grow, which means they can be considered emerging pathogens. A recent example is the large outbreak of foodborne infections caused by EHEC O104H4, which was mainly centred in Germany lasting throughout May and June of 2011. The outbreak strain shows a combination of virulence factors from different E. coli pathotypes, highlighting the way in which the plasticity of bacterial genomes facilitates the emergence of new highly virulent pathogens. Epidemiologic investigations traced the origin of the outbreak to fenugreek seeds imported from Egypt in 2009. The international dimension of the outbreak illustrated the urgent need for improving the epidemiologic surveillance of EHEC. ©2012 Ediciones Mayo, S.A. All rights reserved

The influence of subminimal inhibitory concentrations of benzalkonium chloride on biofilm formation by Listeria monocytogenes

Disinfectants, such as benzalkonium chloride (BAC), are commonly used to control Listeria monocytogenes and other pathogens in food processing plants. Prior studies have demonstrated that the resistance to BAC of L. monocytogenes was associated with the prolonged survival of three strains of molecular serotype 1/2a in an Iberian pork processing plant. Because survival in such environments is related to biofilm formation, we hypothesised that the influence of BAC on the biofilm formation potential of L. monocytogenes might differ between BAC-resistant strains (BAC-R, MIC ≥ 10. mg/L) and BAC-sensitive strains (BAC-S, MIC ≤ 2.5. mg/L). To evaluate this possibility, three BAC-R strains and eight BAC-S strains, which represented all of the molecular serotype 1/2a strains detected in the sampled plant, were compared. Biofilm production was measured using the crystal violet staining method in 96-well microtitre plates. The BAC-R strains produced significantly (p<. 0.05) less biofilm than the BAC-S in the absence of BAC, independent of the rate of planktonic growth. In contrast, when the biofilm values were measured in the presence of BAC, one BAC-R strain (S10-1) was able to form biofilm at 5. mg/L of BAC, which prevented biofilm formation among the rest of the strains. A genetic determinant of BAC resistance recently described in L. monocytogenes (Tn. 6188) was detected in S10-1. When a BAC-S strain and its spontaneous mutant BAC-R derivative were compared, resistance to BAC led to biofilm formation at 5. mg/L of BAC and to a significant (p<. 0.05) stimulation of biofilm formation at 1.25. mg/L of BAC, which significantly (p<. 0.05) reduced the biofilm level in the parent BAC-S strain. Our results suggest that the effect of subminimal inhibitory concentrations of BAC on biofilm production by L. monocytogenes might differ between strains with different MICs and even between resistant strains with similar MICs but different genetic determinants of BAC resistance. For BAC-R strains similar to S10-1, subminimal inhibitory BAC may represent an advantage, compensating for the weak biofilm formation level that might be associated with resistance. Biofilm formation in the presence of increased subminimal inhibitory concentrations of the disinfectant may represent an important attribute among certain resistant and persistent strains of L. monocytogenes. © 2014 Elsevier B.V

Control of Listeria monocytogenes contamination in an Iberian pork processing plant and selection of benzalkonium chloride-resistant strains

The aims of this study were to characterize the different strains of Listeria monocytogenes collected at an Iberian pork processing plant and to investigate whether their specific characteristics were associated with prolonged survival in the plant. Using pulsed-field gel electrophoresis (PFGE), 29 PFGE types were previously identified during a three-year period. Eight of these PFGE types persisted in the plant during that period. In the present study, a subset of 29 PFGE type strains, which represented the 29 different PFGE types, was further characterized by assessing the potential virulence, and using motility, surface attachment, and antimicrobial susceptibility tests. After changing the disinfection procedures in the plant, the isolation rate of L.monocytogenes decreased, and only four of the 29 PFGE types, including three of the eight persistent PFGE types, were found the following year. These four "surviving" PFGE types included three from PCR serogroup IIa that were characterized by their low virulence mutations and low-level resistance to benzalkonium chloride (BAC). Furthermore, these PFGE types comprised the only BAC-resistant isolates found in the study, and they appear to have been selected due to the control of Listeria contamination. The resistance to increased sublethal concentrations of disinfectants may lead to prolonged survival of L.monocytogenes in food plants. © 2013 Elsevier Ltd

Low potential virulence associated with mutations in the inlA and prfA genes in Listeria monocytogenes isolated from raw retail poultry meat

Packaged raw foods can represent a potential source of Listeria monocytogenes contamination when opened at home, and listeriosis is associated with the consumption of undercooked raw foods. The aim of this study was to characterize a group of L. monocytogenes strains isolated from 56 packages of raw chicken meat from a single brand in order to determine the diversity of the strains that dominate in a particular food over time, as well as their pathogenic potential. Forty (71%) samples were found to be positive for L. monocytogenes, and three isolates per sample were subjected to PCR molecular serotyping. Subtyping of 45 isolates from different manufacturing dates (n ~ 40) or different molecular serotype within the same sample (n ~ 5) identified 11 different L. monocytogenes subtypes as defined by pulsed-field gel electrophoresis and sequencing of virulence genes actA and inlA. Two of the subtypes accounted for 51% of the isolates. About 40% of isolates (three subtypes) were found to potentially present attenuated virulence because of the presence of mutations in the prfA and inlA genes. Copyright ©, International Association for Food Protection

Isolation, characterization, and antifungal susceptibility of melanin-deficient mutants of Scedosporium prolificans

Scedosporium prolificans mutants lacking the ability to synthesize melanin were selected after ultraviolet light (UV) irradiation. UV exposure of S. prolificans conidia resulted in a high frequency of melanin-deficient (mel-) mutants. Stable and non-stable morphological variants were found in the population reversion of the mutant phenotype was always to the wild-type phenotype. Based on their morphological differences, these variants were classified into five different groups that were phenotypically characterized. The mel- mutants plus the wild-type strain were examined for in vitro susceptibility to antifungal agents with different and/or the same mechanism of action. There was no apparent difference in minimum inhibitory concentrations when comparing the wild-type and the mel- mutants. Therefore, melanin does not appear to confer protection against the more important antifungal agents in S. prolificans

Simultaneous detection of Listeria monocytogenes in chicken meat enrichments by PCR and reverse-transcription PCR without DNA/RNA isolation

Environmental and food samples can be analyzed using PCR and reverse transcription (RT)-PCR techniques to discriminate between viable and nonviable cells of bacterial pathogens. Here, we describe the use of a commercial lysis buffer, initially designed for mammalian cells, that permits the rapid extraction of bacterial DNA and RNA. The buffer is an RT-PCR-compatible lysis solution in which RNA is stable and can be frozen for later use. RT-PCR is carried out directly after DNase I treatment of crude bacterial lysates using rTth polymerase for RT-PCR in a single tube. Untreated lysate is used for standard PCR. The procedure permits the amplification of either mRNA or DNA of Listeria monocytogenes at a level similar to that obtained with purified nucleic acids. Using lysates obtained with this buffer, nested PCR and RT-PCR assays detected low numbers of L. monocytogenes cells from artificially contaminated chicken meat samples. The simplicity of this system may foster the development of similar buffers specifically designed for bacteria to improve RNA detection methods that can be performed in parallel with DNA analysis. The use of a single buffer decreases the time needed for analysis, is amenable to automation and real-time assays, and might be adaptable to all bacteria and amplification methods

Antibiotic susceptibility in benzalkonium chloride-resistant and-susceptible Listeria monocytogenes strains

This study aimed to investigate whether Listeria monocytogenes strains with resistance to a commonly used biocide display any cross-resistance to antibiotics. Using pulsed-field gel electrophoresis (PFGE), 29 different PFGE types were previously identified in an Iberian pig abattoir and processing plant. Only three PFGE types were resistant to benzalkonium chloride (BAC), but they represented a significant proportion of the PFGE types surviving in the plant after 4 years. In the present study, a subset of 29 strains, representing the 29 different PFGE types, underwent antibiotic susceptibility testing. Antibiotic susceptibility was assessed by Etest, utilizing 12 commonly prescribed antibiotics. All of the 29 strains were susceptible to all of the antibiotics tested. The study revealed that this group of different PFGE types of L. monocytogenes, including those resistant to BAC, possesses uniform sensitivity to antibiotics. © 2014 Mary Ann Liebert, Inc

Antilisterial effect of two bioprotective cultures in a model system of Iberian chorizo fermentation

Summary This study reports the different effects of two bioprotective cultures on the growth of different Listeria monocytogenes strains by a rapid assay simulating the first stage of Iberian chorizo fermentation. Ground pork with or without protective cultures was inoculated with L. monocytogenes and incubated under two different conditions simulating the traditional, slow fermentation temperature (7 °C, 1 day) and a high, fast fermentation temperature (20 °C, 1 day), followed in both cases by storage at 7 °C for 13 days. Both bioprotective cultures reduced the growth of L. monocytogenes by at least 2 log CFU g-1 at the end of both incubation periods compared with a noninoculated culture control lot. The best results were obtained with the strain Lactobacillus sakei CTC494, which exerted a bactericidal effect on L. monocytogenes under both conditions assayed, achieving a 5.4-log reduction after 14 days compared with the control when the initial temperature was 20 °C. © 2013 Institute of Food Science and Technology

The connection between persistent, disinfectant-resistant Listeria monocytogenes strains from two geographically separate Iberian pork processing plants Evidence from comparative genome analysis

The aim of this study was to investigate the basis of the putative persistence of Listeria monocytogenes in a new industrial facility dedicated to the processing of ready-to-eat (RTE) Iberian pork products. Quaternary ammonium compounds, which included benzalkonium chloride (BAC), were repeatedly used as surface disinfectants in the processing plant. Clean and disinfected surfaces were sampled to evaluate if resistance to disinfectants was associated with persistence. Of the 14 isolates obtained from product contact and non-product contact surfaces, only five different pulsed-field gel electrophoresis (PFGE) types were identified during the 27-month study period. Two of these PFGE types (S1 and S10-1) were previously identified to be persistent and BAC-resistant (BACr) strains in a geographically separate slaughterhouse belonging to the same company. The remaining three PFGE types, which were first identified in this study, were also BACr. Whole-genome sequencing and in silico multilocus sequence typing (MLST) analysis of five BACr isolates of the different PFGE types identified in this study showed that the isolate of the S1 PFGE type belonged to MLST sequence type 31 (ST31), a low-virulence type characterized by mutations in the inlA and prfA genes. The isolates of the remaining four PFGE types were found to belong to MLST ST121, a persistent type that has been isolated in several countries. The ST121 strains contained the BAC resistance transposon Tn6188. The disinfection-resistant L. monocytogenes population in this RTE pork product plant comprised two distinct genotypes with different multidrug resistance phenotypes. This work offers insight into the L. monocytogenes subtypes associated with persistence in food processing environments. © 2015, American Society for Microbiology