Last data update: Apr 22, 2024. (Total: 46599 publications since 2009)
Records 1-7 (of 7 Records) |
Query Trace: Shams AM [original query] |
---|
Surface area matters: An evaluation of swabs and surface area for environmental surface sampling of healthcare pathogens
West RM , Shams AM , Chan MY , Rose LJ , Noble-Wang JA . Infect Control Hosp Epidemiol 2022 44 (5) 1-3 Flocked and foam swabs were used to sample five healthcare pathogens from three sizes of steel and plastic coupons; 26 cm(2), 323 cm(2), and 645 cm(2). As surface area increased, 1-2 log(10) decrease in recovered organisms (P < .05) was observed. Sampling 26-cm(2) yielded the optimal median percent of pathogens recovered. |
The Effect of Disinfectants on the Microbial Community on Environmental Healthcare Surfaces using Next Generation Sequencing.
Perry-Dow KA , de Man T , Halpin AL , Shams AM , Rose LJ , Noble-Wang JA . Am J Infect Control 2021 50 (1) 54-60 BACKGROUND: Healthcare-associated infections (HAIs) are a significant economic burden and cause of avoidable morbidity and mortality within healthcare systems. The contribution of environmental contamination to HAI transmission has been recognized, but the mechanisms by which transmission occurs are still being investigated. The objective of this study was to characterize the microbial communities of disinfected, non-critical healthcare surfaces using next generation sequencing technology. METHODS: Composite environmental surface samples were from high-touch surfaces in rooms of patients isolated for infections with multidrug-resistant organisms during their hospitalization. Information on the disinfectant product used and cleaning type (routine or terminal) was collected. 16S rRNA gene amplicon sequencing and analysis were performed. Community analysis was conducted to determine the bacterial composition and compare the detection of target pathogens by culture from 94 Contact Precaution rooms. RESULTS: Overall percent agreement between culture and sequence methods ranged from 52% to 88%. A significant difference was observed in bacterial composition between rooms cleaned with bleach and those cleaned with a quaternary ammonium compound (QAC) for composite 2 (overbed table, intravenous pole, and inner room door handle) (ANOSIM R2 = 0.66, p = 0.005) but not composite 1 (bed rails, television remote control unit, call buttons, and telephone). CONCLUSIONS: Surfaces in bleach-cleaned rooms contained a higher proportion of gram-positive microbiota, whereas rooms cleaned with QAC contained a higher proportion of gram-negative microbiota, suggesting disinfectant products may impact the healthcare environment microbiome. |
Development of a rapid-viability PCR method for detection of Clostridioides difficile spores from environmental samples.
Shams AM , Rose LJ , Noble-Wang J . Anaerobe 2019 61 102077 Clostridioides difficile is a common pathogen that is well known to survive for extended periods of time on environmental healthcare surfaces from fecal contamination. During epidemiological investigations of healthcare-associated infections, it is important to be able to detect whether or not there are viable spores of C. difficile on surfaces. Current methods to detect C. difficile can take up to 7 days for culture and in the case of detection by PCR, viability of the spores cannot be ascertained. Prevention of C. difficile infection in healthcare settings includes adequate cleaning and disinfection of environmental surfaces which increases the likelihood of detecting dead organisms from an environmental sample during an investigation. In this study, we were able to adapt a rapid-viability PCR (RV-PCR) method, first developed for detection of viable Bacillus anthracis spores, for the detection of viable C. difficile spores. RV-PCR uses the change in cycle threshold after incubation to confirm the presence of live organisms. Using this modified method we were able to detect viable C. difficile after 22h of anaerobic incubation in Cycloserine Cefoxitin Fructose Broth (CCFB). This method also used bead beating combined with the Maxwell 16 Casework kit for DNA extraction and purification and a real-time duplex PCR assay for toxin B and cdd3 genes to confirm the identity of the C. difficile spores. Spiked environmental sponge-wipes with and without added organic load were tested to determine the limit of detection (LOD). The LOD from spiked environmental sponge-wipe samples was 10(4) spores/mL but after incubation initial spore levels of 10(1) spores/mL were detected. Use of this method would greatly decrease the amount of time required to detect viable C. difficile spores; incubation of samples is only required for germination (22h or less) instead of colony formation, which can take up to 7 days. In addition, PCR can then quickly confirm or deny the identity of the organism at the same time it would confirm viability. The presence of viable C. difficile spores could be detected at very low levels within 28h total compared to the 2 to 10-day process that would be needed for culture, identification and toxin detection. |
Assessment of the overall and multidrug-resistant organism bioburden on environmental surfaces in healthcare facilities
Shams AM , Rose LJ , Edwards JR , Cali S , Harris AD , Jacob JT , LaFae A , Pineles LL , Thom KA , McDonald LC , Arduino MJ , Noble-Wang JA . Infect Control Hosp Epidemiol 2016 37 (12) 1-7 OBJECTIVE To determine the typical microbial bioburden (overall bacterial and multidrug-resistant organisms [MDROs]) on high-touch healthcare environmental surfaces after routine or terminal cleaning. DESIGN Prospective 2.5-year microbiological survey of large surface areas (>1,000 cm2). SETTING MDRO contact-precaution rooms from 9 acute-care hospitals and 2 long-term care facilities in 4 states. PARTICIPANTS Samples from 166 rooms (113 routine cleaned and 53 terminal cleaned rooms). METHODS Using a standard sponge-wipe sampling protocol, 2 composite samples were collected from each room; a third sample was collected from each Clostridium difficile room. Composite 1 included the TV remote, telephone, call button, and bed rails. Composite 2 included the room door handle, IV pole, and overbed table. Composite 3 included toileting surfaces. Total bacteria and MDROs (ie, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci [VRE], Acinetobacter baumannii, Klebsiella pneumoniae, and C. difficile) were quantified, confirmed, and tested for drug resistance. RESULTS The mean microbial bioburden and range from routine cleaned room composites were higher (2,700 colony-forming units [CFU]/100 cm2; ≤1-130,000 CFU/100 cm2) than from terminal cleaned room composites (353 CFU/100 cm2; ≤1-4,300 CFU/100 cm2). MDROs were recovered from 34% of routine cleaned room composites (range ≤1-13,000 CFU/100 cm2) and 17% of terminal cleaned room composites (≤1-524 CFU/100 cm2). MDROs were recovered from 40% of rooms; VRE was the most common (19%). CONCLUSIONS This multicenter bioburden summary provides a first step to determining microbial bioburden on healthcare surfaces, which may help provide a basis for developing standards to evaluate cleaning and disinfection as well as a framework for studies using an evidentiary hierarchy for environmental infection control. Infect Control Hosp Epidemiol 2016;1-7. |
Persistence of influenza A (H1N1) virus on stainless steel surfaces
Perry KA , Coulliette AD , Rose LJ , Shams AM , Edwards JR , Noble-Wang JA . Appl Environ Microbiol 2016 82 (11) 3239-3245 As annual influenza epidemics continue to cause significant morbidity and economic burden, an understanding of viral persistence and transmission is critical for public health officials and healthcare workers to better protect patients and their family members from infection. The infectivity and persistence of two influenza A (H1N1) strains (A/New Caledonia/20/1999 and A/Brisbane/59/2007) were evaluated on stainless steel (SS) surfaces using three different surfaces matrices (2% fetal bovine serum, 5 mg/mL mucin, and viral medium) at varying absolute humidity conditions (4.1 x 105 mPa, 6.5 x 105 mPa, 7.1 x 105 mPa, 11.4 x 105 mPa, 11.2 x 105 mPa, and 17.9 x 105 mPa) for up to seven days. Influenza virus was deposited onto SS coupons (7.07 cm2) and recovered by agitation and sonicating in viral medium. Viral persistence was quantified using a tissue culture based enzyme-linked immunosorbent assay (ELISA) to determine the median tissue culture infective dose (TCID50) of infectious virus per coupon. Overall, both strains of influenza A virus remained infectious on SS coupons with an approximate 2 log10 loss over seven days. Factors that influenced viral persistence included absolute humidity, strain/absolute humidity interaction, and time (P ≤ 0.01). Further studies into hand transfer of influenza A virus from fomites and the impact of inanimate surface contamination in transmission should be investigated as this study demonstrates prolonged persistence on non-porous surfaces. IMPORTANCE: The study tested the ability of two influenza A H1N1 strains to persist and remain infectious on stainless steel surfaces in varying environmental conditions. It is demonstrated that influenza A H1N1 virus can persist and remain infectious on stainless steel surfaces for 7 days. This raises the question of what role contaminated surfaces play in the transmission of influenza A virus and that additional studies should be conducted to assess this. |
Chlorine dioxide inactivation of bacterial threat agents
Shams AM , O'Connell H , Arduino MJ , Rose LJ . Lett Appl Microbiol 2011 53 (2) 225-30 AIMS: To evaluate the efficacy of chlorine dioxide (ClO(2) ) against seven species of bacterial threat (BT) agents in water. METHODS AND RESULTS: Two strains of Bacillus anthracis spores, Yersinia pestis, Francisella tularensis, Burkholderia pseudomallei, Burkholderia mallei, and Brucella species were each inoculated into a ClO(2) solution with an initial concentration of 2.0 mg l(-1) (spores only) and 0.25 mg l(-1) (all other bacteria) at pH 7 or 8, 5 degrees C or 25 degrees C. At 0.25 mg l(-1) in potable water, six species were inactivated by at least 3 orders of magnitude within 10 min. B. anthracis spores required up to 7 h at 5 degrees C for the same inactivation with 2.0 mg l(-1) ClO(2) . CONCLUSIONS: Typical ClO(2) doses used in water treatment facilities would be effective against all bacteria tested except B. anthracis spores which would require up to 7 h with the largest allowable dose of 2 mg l(-1) ClO(2) . Other water treatment processes may be required in addition to ClO(2) disinfection for effective spore removal or inactivation. SIGNIFICANCE AND IMPACT OF STUDY: The data obtained from this study provides valuable information for water treatment facilities and public health officials in the event that a potable water supply is contaminated with these BT agents. |
Chlorine disinfection of Francisella tularensis
O'Connell HA , Rose LJ , Shams AM , Arduino MJ , Rice EW . Lett Appl Microbiol 2011 52 (1) 84-6 AIMS: To determine the range of free available chlorine (FAC) required for disinfection of the live vaccine strain (LVS) and wild-type strains of Francisella tularensis. METHODS AND RESULTS: Seven strains of planktonic F. tularensis were exposed to 0.5 mg.l(-1) FAC for two pH values, 7 and 8, at 5 and 25 degrees C. LVS was inactivated 2 to 4 times more quickly than any of the wild-type F. tularensis strains at pH 8 and 5 degrees C. CONCLUSIONS: Free available chlorine residual concentrations routinely maintained in drinking water distribution systems would require up to two hours to reduce all F. tularensis strains by 4 log10. LVS was inactivated most quickly of the tested strains. SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides contact time (CT) values that are useful for drinking water risk assessment and also suggests that LVS may not be a good surrogate in disinfection studies. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Apr 22, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure