scholarly journals Particulate Matter in a Hospital Environment: as Potential Reservoir for Hospital Strains

2019 ◽  
Vol 18 (4) ◽  
pp. 82-92 ◽  
Author(s):  
E. A. Chezganova ◽  
O. S. Efimova ◽  
S. A. Sozinov ◽  
A. R. Efimova ◽  
V. M. Sakharova ◽  
...  

Relevance. For decades, many aspects of aerosol transmission of hospital pathogens have been and remain the subject of scientific debate. Despite fairly detailed studies of the mechanism of microbial aerosols formation, distribution, the role of particulate matter in the formation of antibiotic resistance and multidrug-resistant hospital clones of microorganisms is still unclear. Aim. To investigate physicochemical properties and microbiological diversity of hospital particulate matter. Materials and Methods. Shape and size of particulates was assessed by means of scanning electron microscopy and dynamic light scattering while elemental analysis was performed using energy-dispersive X-ray spectroscopy and high-temperature catalytic oxidation. Microbial profiling was conducted using polymerase chain reaction and Vitek 2 biochemical analyzer. Results. Hospital particulate matter included globular and fibrillary particles consisting of carbon, oxygen, calcium, silicon, aluminium, and sulfur. Intriguingly, microfiber particles had higher oxygen and calcium content along with the lower level of carbon in mineral but not organic component. Differential localisation of silicon and calcium in elemental mapping suggested that hospital particulate matter was composed of aluminosilicate minerals and calcium compounds. Among the microorganisms, we found multidrug-resistant strains Raoultella ornithinolytica, Staphylococcus pseudintermedius, Pantoea spp., Pseudomonas aeruginosa, Enterococcus faecium and additionally Pasteurella canis in hospital particulate matter samples. Conclusions. Particulate matter in the hospital environment might be considered as a potential reservoir for the evolution of antibiotic resistance and multidrug-resistant strains.

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 639
Author(s):  
Evgenia Chezganova ◽  
Olga Efimova ◽  
Vera Sakharova ◽  
Anna Efimova ◽  
Sergey Sozinov ◽  
...  

Most healthcare-associated infections (HCAIs) develop due to the colonisation of patients and healthcare workers by multidrug-resistant organisms (MDRO). Here, we investigated whether the particulate matter from the ventilation systems (Vent-PM) of health facilities can harbour MDRO and other microbes, thereby acting as a potential reservoir of HCAIs. Dust samples collected in the ventilation grilles and adjacent air ducts underwent a detailed analysis of physicochemical properties and biodiversity. All Vent-PM samples included ultrafine PM capable of reaching the alveoli. Strikingly, >70% of Vent-PM samples were contaminated, mostly by viruses (>15%) or multidrug-resistant and biofilm-producing bacterial strains (60% and 48% of all bacteria-contaminated specimens, respectively). Total viable count at 1 m from the ventilation grilles was significantly increased after opening doors and windows, indicating an association between air flow and bacterial contamination. Both chemical and microbial compositions of Vent-PM considerably differed across surgical vs. non-surgical and intensive vs. elective care units and between health facilities located in coal and chemical districts. Reduced diversity among MDRO and increased prevalence ratio in multidrug-resistant to the total Enterococcus spp. in Vent-PM testified to the evolving antibiotic resistance. In conclusion, we suggest Vent-PM as a previously underestimated reservoir of HCAI-causing pathogens in the hospital environment.


2003 ◽  
Vol 24 (4) ◽  
pp. 275-279 ◽  
Author(s):  
Cosmina Zeana ◽  
Elaine Larson ◽  
Jyoti Sahni ◽  
S. J. Bayuga ◽  
Fann Wu ◽  
...  

AbstractObjective:To explore the role of the community as a potential reservoir forAcinetobacter baumannii.Design:Antimicrobial resistance patterns and genotypes ofA. baumanniiisolates from patients in two Manhattan hospitals were compared with those ofA. baumanniiisolates from the hands of community members.Results:A total of 103 isolates from two hospitals (hospital A, 81; hospital B, 22) and 23 isolates from community residents were studied. Of the hospital isolates, 36.6% were multidrug resistant (hospital A, 68.2%; hospital B, 27.8%). In contrast, there were no multidrug-resistant isolates from the community (P< .005 between hospital and community). The prevalence ofA. baumanniion the hands of community residents was 10.4% (23 of 222). By molecular typing, 42 strains of A.baumanniiwere identified. Of the isolates from hospital A and hospital B, 55.6% (45 of 81) and 68.2% (15 of 22), respectively, were indistinguishable or closely related. In contrast, most community (83.3%) isolates were unrelated (P= .001 between hospital and community).Conclusion:Acinetobacterisolates from the community, characterized by a large variety of unrelated strains (83.3%), were distinct from the hospital isolates, of which 58.3% were closely related. The absence of multidrug-resistant strains in the community compared with 36.6% prevalence among hospital isolates suggests that the reservoir for epidemic strains resides in the hospital environment itself. To our knowledge, this is the first study to examine the community as a potential reservoir for hospital strains ofA. baumannii.


2021 ◽  
Vol 98 (3) ◽  
pp. 266-275
Author(s):  
E. A. Chezganova ◽  
O. S. Efimova ◽  
V. M. Sakharova ◽  
A. R. Efimova ◽  
S. A. Sozinov ◽  
...  

Background. Most healthcare-associated infections (HAI) develop due to a colonization of patients and healthcare workers by hospital strains of pathogens. The aim to study was to assess whether the dust within the health facilities can harbor microorganisms acting as a reservoir of HAIs.Materials and methods. Dust samples collected in the air ducts and ventilation grilles of health facilities underwent a detailed physicochemical analysis by means of scanning electron microscopy, dynamic light scattering, energy-dispersive X-ray spectroscopy, and high-temperature catalytic oxidation. Bacterial and viral diversity was investigated using an automated biochemical analyzer and polymerase chain reaction, respectively. Investigation of the microenvironment included detection of biofilms using a catalase indicator and quantification of viable microorganisms per 1 m3 air.Results. Dust from the hospital ventilation grilles and air ducts was contaminated with microorganisms in 71.13% of cases. Strikingly, multidrug-resistant and biofilm-forming strains have been found in 69.4% and 48.0% of samples, respectively. The total viable count before and after opening doors and windows was 276 and 462 colony-forming units/m3 respectively (p = 0.046). Biodiversity was represented by 21 genera of microorganisms which were consistently detected upon 6 months of follow-up. All samples contained a nanosized particulate matter. Chemical elements comprising dust were carbon (16.26–50.69%), oxygen (20.02–37.50%), nitrogen (1.59–25.03%), hydrogen (2.03–6.67%), sulfur (0.15–2.38%), calcium (0.19–7.49%), silicon (0.21–4.64%), chlorine (0.05–2.83%), sodium (0.07–1.86%), aluminum (0.36–1.78%), iron (0.08–1.61%), magnesium (0.11–1.40%), potassium (0.04–0.85%), and phosphorus (0.04–0.81%).Discussion. A wide range of multidrug-resistant strains of bacteria, detected in a hospital particulate matter with a diverse chemical composition, indicates the persistence of HAI-causing pathogens in the hospital environment.Conclusion. Dust from the ventilation grilles and adjacent air ducts should be considered as an additional reservoir of multidrug-resistant strains of bacteria in the healthcare settings.


2019 ◽  
Author(s):  
Kern Rei Chng ◽  
Chenhao Li ◽  
Denis Bertrand ◽  
Amanda Hui Qi Ng ◽  
Junmei Samantha Kwah ◽  
...  

AbstractThere is growing attention surrounding hospital acquired infections (HAIs) due to high associated healthcare costs, compounded by the scourge of widespread multi-antibiotic resistance. Although hospital environment disinfection is well acknowledged to be key for infection control, an understanding of colonization patterns and resistome profiles of environment-dwelling microbes is currently lacking. We report the first extensive genomic characterization of microbiomes (428), common HAI-associated microbes (891) and transmissible drug resistance cassettes (1435) in a tertiary hospital environment based on a 3-timepoint sampling (1 week and >1 year apart) of 179 sites from 45 beds. Deep shotgun metagenomic sequencing unveiled two distinct ecological niches of microbes and antibiotic resistance genes characterized by biofilm-forming and human microbiome influenced environments that display corresponding patterns of divergence over space and time. To study common nosocomial pathogens that were typically present at low abundances, a combination of culture enrichment and long-read nanopore sequencing was used to obtain thousands of high contiguity genomes (2347), phage sequences (1693) and closed plasmids (5910), a significant fraction of which (>60%) are not represented in current sequence databases. These high-quality assemblies and metadata enabled a rich characterization of resistance gene combinations, phage diversity, plasmid architectures, and the dynamic nature of hospital environment resistomes and their reservoirs. Phylogenetic analysis identified multidrug resistant strains as being more widely distributed and stably colonizing across hospital sites. Further genomic comparisons with clinical isolates across multiple species supports the hypothesis that multidrug resistant strains can persist in the hospital environment for extended periods (>8 years) to opportunistically infect patients. These findings highlight the importance of characterizing antibiotic resistance reservoirs in the hospital environment and establishes the feasibility of systematic genomic surveys to help target resources more efficiently for preventing HAIs.


2015 ◽  
Vol 112 (23) ◽  
pp. 7273-7278 ◽  
Author(s):  
Michael S. Gilmore ◽  
Marcus Rauch ◽  
Matthew M. Ramsey ◽  
Paul R. Himes ◽  
Sriram Varahan ◽  
...  

Multidrug-resistantEnterococcus faecalispossess numerous mobile elements that encode virulence and antibiotic resistance traits as well as new metabolic pathways, often constituting over one-quarter of the genome. It was of interest to determine how this large accretion of mobile elements affects competitive growth in the gastrointestinal (GI) tract consortium. We unexpectedly observed that the prototype clinical isolate strain V583 was actively killed by GI tract flora, whereas commensal enterococci flourished. It was found that killing of V583 resulted from lethal cross-talk between accumulated mobile elements and that this cross-talk was induced by a heptapeptide pheromone produced by nativeE. faecalispresent in the fecal consortium. These results highlight two important aspects of the evolution of multidrug-resistant enterococci: (i) the accretion of mobile elements inE. faecalisV583 renders it incompatible with commensal strains, and (ii) because of this incompatibility, multidrug-resistant strains sharing features found in V583 cannot coexist with commensal strains. The accumulation of mobile elements in hospital isolates of enterococci can include those that are inherently incompatible with native flora, highlighting the importance of maintaining commensal populations as means of preventing colonization and subsequent infection by multidrug-resistant strains.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Justine Fri ◽  
Henry A. Njom ◽  
Collins N. Ateba ◽  
Roland N. Ndip

Thirty-three (33) isolates of methicillin-resistant Staphylococcus aureus (MRSA) from healthy edible marine fish harvested from two aquaculture settings and the Kariega estuary, South Africa, were characterised in this study. The phenotypic antimicrobial susceptibility profiles to 13 antibiotics were determined, and their antibiotic resistance determinants were assessed. A multiplex PCR was used to determine the epidemiological groups based on the type of SCCmec carriage followed by the detection of staphylococcal enterotoxin-encoding genes sea-sed and the Panton Valentine leucocidin gene (pvl). A high antibiotic resistance percentage (67–81%) was observed for Erythromycin, Ampicillin, Rifampicin, and Clindamycin, while maximum susceptibility to Chloramphenicol (100%), Imipenem (100%), and Ciprofloxacin (94%) was recorded. Nineteen (58%) of the MRSA strains had Vancomycin MICs of ≤2 μg/mL, 4 (12%) with MICs ranging from 4–8 μg/mL, and 10 (30%) with values ≥16 μg/mL. Overall, 27 (82%) isolates were multidrug-resistant (MDR) with Erythromycin-Ampicillin-Rifampicin-Clindamycin (E-AMP-RIP-CD) found to be the dominant antibiotic-resistance phenotype observed in 4 isolates. Resistance genes such as tetM, tetA, ermB, blaZ, and femA were detected in two or more resistant strains. A total of 19 (58%) MRSA strains possessed SCCmec types I, II, or III elements, characteristic of healthcare-associated MRSA (HA-MRSA), while 10 (30%) isolates displayed SCCmec type IVc, characteristic of community-associated MRSA (CA-MRSA). Six (18%) of the multidrug-resistant strains of MRSA were enterotoxigenic, harbouring the see, sea, or sec genes. A prevalence of 18% (6/33) was also recorded for the luk-PVL gene. The findings of this study showed that marine fish contained MDR-MRSA strains that harbour SCCmec types, characteristic of either HA-MRSA or CA-MRSA, but with a low prevalence of enterotoxin and pvl genes. Thus, there is a need for continuous monitoring and implementation of better control strategies within the food chain to minimise contamination of fish with MDR-MRSA and the ultimate spread of the bug.


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
M Fattorini ◽  
C Quercioli ◽  
G Messina ◽  
N Nante

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug resistant organism (MDRO) frequently involved in skin, soft tissue and bone infections. Moreover, it is one of the most frequently isolated pathogen in bloodstream infections in European countries. Because of its capacity to survive on inanimate surfaces, this microorganism could be detected not only on hospital environment, but also in other healthcare settings such as ambulances. We performed a systematic review in order to study the level of MRSA contamination in ambulances (vehicle surfaces and medical equipment). Methods In March 2019 we searched studies in PubMed using the key search terms “MRSA, ambulance”. We included different designs of studies in English. Results The research yielded 18 publications: after title, abstract and full text’s analysis, 9 manuscripts were included in this review. Studies were conducted from 2007 to 2018 in USA, Egypt, Poland, Germany and South Korea. Overall, the number of ambulances sampled for MRSA was 511 (min. 3-max. 150), and 64 (12.5%) resulted contaminated by MRSA. Sampling points examined for each vehicle varied from 5 to 33, for a total of 5872 (min. 39-max. 2136) samplings performed. The amount of MRSA positive samplings was 145/5872 (2.5%) (min. 1-max. 43). Stretcher resulted the most frequently contaminated fomite (29 of the 145 MRSA positive samplings, 20%). Conclusions Despite MRSA prevalence is decreasing in Europe, recent studies showed how this MDRO could still be responsible of a remarkable burden in terms of attributable deaths and costs. Implementing effective sanitation procedures with a continuative monitoring of the processes is highly recommended in all the healthcare settings, including ambulances. Automated terminal disinfection of these vehicles, adopting technologies such as ultraviolet germicidal irradiation or hydrogen peroxide aerosol, could reduce bacterial contamination hosted on surfaces and medical equipment. Key messages Although the percentage of isolates of MRSA in European countries is decreasing, the burden this multidrug resistant organism in terms of mortality and costs remains remarkable. Ambulances must be considered as a potential reservoir of MRSA because of its ability to survive on inanimate surfaces, and adequate sanitation procedures should be frequently performed.


2019 ◽  
Vol 63 (12) ◽  
Author(s):  
Xiao Yu ◽  
Beiwen Zheng ◽  
Jing Zhang ◽  
Hao Xu ◽  
Tingting Xiao ◽  
...  

ABSTRACT We report the characterization of six carbapenem-resistant Raoultella spp. (CRRS) in our hospital and a genomic analysis of 58 publicly available isolates. CRRS isolates are sporadically identified around the world, and different transposons carrying carbapenemases were the resistant mechanisms. Mobile genetic elements play an important role in acquiring antibiotic resistance genes from the hospital. An improved understanding of these transposon and targeted control measures will be very valuable to prevent CRRS dissemination.


Author(s):  
S. Jayashree ◽  
K.G. Rajeshwari ◽  
Mita D. Wadekar

Acinetobacter species cause infections that are difficult to control due to multi-drug resistance and are noted for their intrinsic resistance to antibiotics and for their ability to acquire genes encoding resistance for the production of beta-lactamases and Aminoglycoside-modifying enzymes. MBLs are molecular class B and functional group 3 beta-lactamases which have the capability of hydrolyzing all β-lactams except the Monobactam, Aztreonam. Of several MBLs, only IMP, VIM and SIM types have been detected in these species. To analyze the antibiotic resistance patterns among Acinetobacter isolates and to detect Carbapenemase and MBL among MDR Acinetobacter isolates. The descriptive study of all phenotypically identified strains and multidrug-resistant strains of Acinetobacter species was conducted. A total of 303 isolates were isolated from various samples. They were processed and identified by standard Microbiological procedures. The antibiotics susceptibility testing was performed by Kirby- Bauer disc diffusion method using CLSI guidelines. Carbapenemase production was detected by employing 3 phenotypic test methods (MHT, CDM and DDST). Of 6355 samples processed, 303 were found to be Acinetobacter species, among those 50 were multidrug-resistant strains. The highest isolation of MDR Acinetobacter was from endotracheal tube tip (42%) and pus sample (32%). The majority of MDR Acinetobacter infection was found in male patients 36 (72%) compared to female patients 14 (28%). The majority of the strains were isolated from patients >/ 60 years of age group (%). A number of these isolates were more from ICU wards (30%) followed by Surgery wards (24%). Higher resistance for the Piperacillin/tazobactam ((82%), followed by Ceftazidime (80%), Imipenem (76%) etc. and the most susceptible drug was found to be the Tigecycline (82%) followed by Colistin (80%). Carbapenemase production was detected by MHT and 24 (48%) isolates were MHT positive. MBL production was detected by CDM and 34 (68%) isolates were CDM positive and by DDST 30 (60%) isolates were positive. Acinetobacter species are increasingly important nosocomial pathogens and are capable of rapid adaptation to the hospital environment. The variety of potential source of contamination or infection with these species in the hospital environment makes control of outbreaks caused by these difficult.


2019 ◽  
Vol 6 (12) ◽  
pp. 310-315
Author(s):  
Nergis Aşgın ◽  
Emre Taşkın

Objective: In this study, we aim to determine the frequency of antibiotic resistance and five virulence genes in Enterococcus species and the relationship between antibiotic resistance and virulence genes. Material and Methods: A total of 86 Enterococcus strains isolated from inpatients between 2015 and 2016 were included. Identification and antibiotic susceptibilities of strains were determined using a BD Phoenix fully automated system. The presence of virulence-associated genes (esp, gel E, asa1, hyl, and cyl) were investigated by using PCR method. Results: Of the 86 Enterococcus strains, 53 (61.6%) and 33 (38.4%) were Enterococcus faecium and Enterococcus faecalis, respectively. Vancomycin and high-level gentamicin resistance (HLGR) in E. faecalis strains were 0.6% and 60.6%, respectively. Furthermore, 52 of the 53 E. faecium strains were both vancomycin-resistant and HLGR. The frequency of esp, gel E, asa1, cyl, and hyl was 91.9%, 60.5%, 54.7%, 43%, and 26.7%, respectively.  The asa 1, cyl, and gel E genes were detected at high frequencies in vancomycin-susceptible and non-HLGR strains, whereas hyl gene was detected at high frequencies in vancomycin-resistant and HLGR strains. Conclusion: Virulence genes were more frequent in vancomycin-susceptible and non-HLGR Enterococcus strains than in the resistant strains. Although infections caused by multidrug-resistant strains are difficult to treat, it should be considered that susceptible strains have more virulence genes. This may reduce the in vivo efficacy of drugs and lead to treatment failures. Therefore, in addition to the in vitro susceptibilities of drugs, clinical efficacy should be monitored.


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