Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-19 (of 19 Records) |
Query Trace: Shams A[original query] |
---|
Top sources and trends in consumption of total energy and energy from solid fats and added sugars among youth 2-18 years: United States 2009-2018
Wambogo EA , O'Connor LE , Shams-White MM , Herrick KA , Reedy J . Am J Clin Nutr 2022 116 (6) 1779-1789 BACKGROUND: High energy intake from non-nutrient dense sources correlates with poorer diet quality. OBJECTIVES: To, 1) estimate total energy intake, and energy from solid fats and added sugars, and combined (SOFAS), and identify their top food category sources for ages 2-18 years in 2015-2018, and 2) describe trends over time in 2009-2018. DESIGN: Data were from the National Health and Nutrition Examination Survey. Pairwise differences were examined using univariate t statistics (2015-2018, n=5,038), and trends by age, and over time (2009-2018, n=14,038) examined using orthogonal polynomials. RESULTS: In 2015-2018, SOFAS contributed (mean [SE], 30.0% [0.3%]) of total energy. Solid fats 16.1% [0.2%] and added sugars 13.8% [0.2%] each contributed >10%. The contribution of added sugars increased with age from 11.1% (2-3 years) to 14.4% (14-18 years), and was higher for all other race/Hispanic origins than Non-Hispanic Asians. Top five sources of energy were sweet bakery products, savory snacks, pizza, other mixed dishes, and unflavored milk, and for SOFAS also included soft drinks, other desserts, candy and snack bars. Total energy did not change between 2009-2018, but energy from SOFAS, and servings of solid fats, and added sugars declined. The contribution of unflavored milk to total energy declined for all ages and most race/Hispanic origins. Fruit drinks (all ages) and soft drinks (9-18 years) remained among top added sugars sources despite declines. The contribution of sweet bakery products to energy from SOFAS increased for most ages, and candy and snack bars to energy from added sugars. CONCLUSIONS: In 2015-2018, SOFAS contributed over 30% of total energy for ages 2-18 years, which doubled the Dietary Guidelines for Americans' recommended limit of 15%. Top five sources of total energy were similar to those of solid fats, and those of SOFAs similar to those of added sugars. These results may inform public health efforts for improving diet quality. |
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. |
Tumorigenic response in lung tumor susceptible A/J mice after sub-chronic exposure to calcium chromate or iron (III) oxide
Zeidler-Erdely PC , Falcone LM , Antonini JM , Fraser K , Kashon ML , Battelli LA , Salmen R , Trainor T , Grose L , Friend S , Yang C , Erdely A . Toxicol Lett 2020 334 60-65 Iron oxides are Group 3 (not classifiable as to its carcinogenicity to humans) according to the International Agency for Research on Cancer (IARC). Occupational exposures during iron and steel founding and hematite underground mining as well as other iron predominant exposures such as welding are Group 1 (carcinogenic to humans). The objective of this study was to investigate the potential of iron as iron (III) oxide (Fe(2)O(3)) to initiate lung tumors in A/J mice, a lung tumor susceptible strain. Male A/J mice were exposed by oropharyngeal aspiration to suspensions of Fe(2)O(3) (1 mg) or calcium chromate (CaCrO(4); 100 µg; positive control) for 26 weeks (once per week). Shams were exposed to 50 µL phosphate buffered saline (PBS; vehicle). Mice were euthanized 70 weeks after the first exposure and lung nodules were enumerated. Both CaCrO(4) and Fe(2)O(3) significantly increased gross-observed lung tumor multiplicity in A/J mice (9.63 ± 0.55 and 3.35 ± 0.30, respectively) compared to sham (2.31 ± 0.19). Histopathological analysis showed that bronchiolo-alveolar adenomas (BAA) and carcinomas (BAC) were the primary lung tumor types in all groups and were increased in the exposed groups compared to sham. BAC were significantly increased (146 %) in the CaCrO(4) group and neared significance in the Fe(2)O(3) group (100 % increase; p = 0.085). BAA and other histopathological indices of toxicity followed the same pattern with exposed groups increased compared to sham control. In conclusion, evidence from this study, in combination with our previous studies, demonstrate that exposure to iron alone may be a potential risk factor for lung carcinogenesis. |
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. |
Challenges in identifying Candida auris in hospital clinical laboratories: a need for hospital and public health laboratory collaboration in rapid identification of an emerging pathogen
Durante AJ , Maloney MH , Leung VH , Razeq JH , Banach DB . Infect Control Hosp Epidemiol 2018 39 (8) 1-2 Candida auris is an emerging fungus that poses a considerable threat to US healthcare facilities and their patients. Patients exposed to C. auris can develop invasive infection, which can be fatal,Reference Lockhart, Etienne and Vallabhaneni 1 or can become colonized, which poses long-term transmission risks. Once introduced into a healthcare facility, C. auris can spread through contact with affected patients and contaminated surfaces.Reference Tsay, Welsh and Adams 2 The organism can persist in the environment,Reference Welsh, Bentz and Shams 3 and quaternary ammonium disinfectants demonstrate poor activity against it.Reference Cadnum, Shaikh, Piedrahita and Sankar 4 Candida auris is often multidrug-resistant,Reference Lockhart, Etienne and Vallabhaneni 1 , Reference Cadnum, Shaikh, Piedrahita and Sankar4 and its detection is challenging because it can be misidentified by some biochemically based identification methods. For example, the API 20 C (bioMerieux, Marcy-l’Etoile, France) can misidentify C. auris as C. sake or Rhodotorula glutinis, and the Vitek 2 (bioMerieux) can misidentify C. auris as C. haemulonii or C. duobushaemulonii.Reference Mizusawa, Miller and Green 5 Rapid and accurate C. auris detection would help hospitals to guide infection control activities intended to prevent the spread of the fungus within and between facilities and to properly plan antifungal treatment. We surveyed laboratories that serve Connecticut’s acute-care hospitals to assess their capability to identify C. auris. The information was collected to guide statewide hospital prevention efforts. |
Sternal surgical site infection in Egypt following coronary artery bypass graft surgery: Incidence and risk factors
Abdou E , Westercamp M , Girgis S , Sabry M , Sayyouh O , Talaat M . J Hosp Infect 2018 100 (4) 456-458 Sternal wound surgical site infection (SSI) following coronary artery bypass graft (CABG) is a serious but preventable surgical complication [1]. Whereas evidence suggests that the burden of sternal SSI is greatest in low- and middle-income settings, the majority of published incidence measure and risk factor assessment is limited to high-income/high-resource settings [2], [3]. Here we present 12-month sternal SSI incidence following CABG surgery with associated risk factors in a high-functioning, but resource-limited, healthcare setting. The study was conducted between July 2015 and June 2016 at the 200-bed Cardiovascular Hospital at Ain Shams University Hospitals (CVH-ASUHs). The study population was restricted to adult patients (aged ≥18 years) who underwent a scheduled, non-emergent, CABG procedure. Only the sternal surgical wound was assessed for infection. |
Notes from the field: Investigation of carbapenemase-producing carbapenem-resistant Enterobacteriaceae among patients at a community hospital - Kentucky, 2016
Chae SR , Yaffee AQ , Weng MK , Ham DC , Daniels K , Wilburn AB , Porter KA , Flinchum AH , Boyd S , Shams A , Walters MS , Kallen A . MMWR Morb Mortal Wkly Rep 2018 66 (5152) 1410 Carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) express plasmid-encoded carbapenemases, enzymes that inactivate carbapenem antibiotics. They have the potential for epidemic spread through person-to-person transmission and horizontal transfer of resistance mechanisms (1,2). Typically, CP-CRE are associated with health care exposure. Clinical CRE infections can have mortality rates as high as 50% (3); however, the majority of CRE patients are asymptomatic. These asymptomatic colonized patients can serve as a source for transmission to other patients (4). |
Survival, persistence, and isolation of the emerging multidrug-resistant pathogenic yeast Candida auris on a plastic healthcare surface
Welsh RM , Bentz ML , Shams A , Houston H , Lyons A , Rose LJ , Litvintseva AP . J Clin Microbiol 2017 55 (10) 2996-3005 The emerging multidrug-resistant pathogenic yeast Candida auris represents a serious threat to global health. Unlike most other Candida species, this organism appears to be commonly transmitted within healthcare facilities and is capable of causing healthcare-associated outbreaks. To better understand the epidemiology of this emerging pathogen we investigated the ability of C. auris to persist on plastic surfaces common in healthcare settings and compared with that of Candida parapsilosis, a species known to colonize the skin and plastics. Specifically, we compiled comparative and quantitative data essential to understanding the vehicles of spread and the ability of both species to survive and persist on plastic surfaces under controlled conditions (25 degrees C & 57% relative humidity), such as those found in healthcare settings. When a test suspension of 104 cells was applied and dried on plastic surfaces, C. auris remained viable for at least 14 days and C. parapsilosis 28 days, as measured by colony forming units (CFU). However, survival measured by esterase activity was higher for C. auris than C. parapsilosis throughout the 28 day study. Given the notable length of time Candida survive and persist outside their host, we developed methods to more effectively culture C. auris from patients and their environment. Using our enrichment protocol, public health laboratories and researchers can now readily isolate C. auris from complex microbial communities (such as patient skin, nasopharynx, and stool) as well as environmental biofilms, in order to better understand and prevent C. auris colonization and transmission. |
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. |
Effects of acute inhalation of aerosols generated during resistance spot welding with mild-steel on pulmonary, vascular and immune responses in rats
Zeidler-Erdely PC , Meighan TG , Erdely A , Fedan JS , Thompson JA , Bilgesu S , Waugh S , Anderson S , Marshall NB , Afshari A , McKinney W , Frazer DG , Antonini JM . Inhal Toxicol 2014 26 (12) 1-11 Spot welding is used in the automotive and aircraft industries, where high-speed, repetitive welding is needed to join thin sections of metal. Epoxy adhesives are applied as sealers to the metal seams. Pulmonary function abnormalities and airway irritation have been reported in spot welders, but no animal toxicology studies exist. Therefore, the goal of this study was to investigate vascular, immune and lung toxicity measures after exposure to these metal fumes in an animal model. Male Sprague-Dawley rats were exposed by inhalation to 25 mg/m3 to either mild-steel spot welding aerosols with sparking (high metal, HM) or without sparking (low metal, LM) for 4 h/d for 3, 8 and 13 d. Shams were exposed to filtered air. Bronchoalveolar lavage (BAL), lung gene expression and ex vivo BAL cell challenge were performed to assess lung toxicity. Lung resistance (RL) was evaluated before and after challenge with inhaled methacholine (MCh). Functional assessment of the vascular endothelium in isolated rat tail arteries and leukocyte differentiation in the spleen and lymph nodes via flow cytometry was also done. Immediately after exposure, baseline RL was significantly elevated in the LM spot welding aerosols, but returned to control level by 24 h postexposure. Airway reactivity to MCh was unaffected. Lung inflammation and cytotoxicity were mild and transient. Lung epithelial permeability was significantly increased after 3 and 8 d, but not after 13 d of exposure to the HM aerosol. HM aerosols also caused vascular endothelial dysfunction and increased CD4+, CD8+ and B cells in the spleen. Only LM aerosols caused increased IL-6 and MCP-1 levels compared with sham after ex vivo LPS stimulation in BAL macrophages. Acute inhalation of mild-steel spot welding fumes at occupationally relevant concentrations may act as an irritant as evidenced by the increased RL and result in endothelial dysfunction, but otherwise had minor effects on the lung. |
Outbreak of Burkholderia cepacia complex among ventilated pediatric patients linked to hospital sinks
Lucero CA , Cohen AL , Trevino I , Rupp AH , Harris M , Forkan-Kelly S , Noble-Wang J , Jensen B , Shams A , Arduino MJ , Lipuma JJ , Gerber SI , Srinivasan A . Am J Infect Control 2011 39 (9) 775-8 We investigated a cluster of Burkholderia cepacia complex colonization in ventilated pediatric patients. Isolates from 15 patients, 2 sink drains, and several ventilator components were found to belong to a single B cenocepacia clone. Hospital tap water used during oral and tracheostomy care was identified as the most likely mechanism for transmission. |
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. |
The Treatment Advocacy Program: a randomized controlled trial of a peer-led safer sex intervention for HIV-infected men who have sex with men
McKirnan DJ , Tolou-Shams M , Courtenay-Quirk C . J Consult Clin Psychol 2010 78 (6) 952-63 OBJECTIVE: Primary care may be an effective venue for delivering behavioral interventions for sexual safety among HIV-positive men who have sex with men (MSM); however, few studies show efficacy for such an approach. We tested the efficacy of the Treatment Advocacy Program (TAP), a 4-session, primary-care-based, individual counseling intervention led by HIV-positive MSM "peer advocates" in reducing unprotected sex with HIV-negative or unknown partners (HIV transmission risk). METHOD: We randomized 313 HIV-positive MSM to TAP or standard care. HIV transmission risk was assessed at baseline, 6 months, and 12 months (251 participants completed all study waves). We conducted intent-to-treat analyses using general estimating equations to test the interaction of group (TAP vs. standard care) by follow-up period. RESULTS: At study completion, TAP participants reported greater transmission risk reduction than did those receiving standard care, chi2(2, N = 249) = 6.6, p = .04. Transmission risk among TAP participants decreased from 34% at baseline to about 20% at both 6 and 12 months: Transmission risk ranged from 23% to 25% among comparison participants. CONCLUSIONS: TAP reduced transmission risk among HIV-positive MSM, although results are modest. Many participants and peer advocates commented favorably on the computer structure of the program. We feel that the key elements of TAP-computer-based and individually tailored session content, delivered by peers, in the primary care setting-warrant further exploration. |
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. |
Exposure to cigarette smoke inhibits the pulmonary T cell response to influenza and Mycobacterium tuberculosis
Feng Y , Kong Y , Barnes PF , Huang FF , Klucar P , Wang X , Samten B , Sengupta M , Machona B , Donis R , Tvinnereim AR , Shams H . Infect Immun 2010 79 (1) 229-37 Smoking is associated with increased susceptibility to tuberculosis and influenza. However, little information is available on the mechanisms underlying this increased susceptibility. Mice were unexposed or exposed to cigarette smoke, and then infected with M. tuberculosis by aerosol or influenza A by intranasal infection. Some mice were given a DNA vaccine encoding an immunogenic M. tuberculosis protein. IFN-gamma production by T-cells from the lungs and spleens was measured. Cigarette smoke exposure inhibited lung T-cell production of interferon-gamma, during stimulation in vitro with anti-CD3, after vaccination with a construct expressing an immunogenic mycobacterial protein, and during infection with M. tuberculosis and influenza A virus in vivo. Reduced interferon-gamma production was mediated through decreased phosphorylation of transcription factors that positively regulate interferon-gamma expression. Cigarette smoke exposure increased the bacterial burden in mice infected with M. tuberculosis, and increased weight loss and mortality in mice infected with influenza virus. This study provides the first demonstration that cigarette smoke exposure directly inhibits the pulmonary T-cell response to M. tuberculosis and influenza virus in a physiologically relevant animal model, increasing susceptibility to both pathogens. |
Multistate outbreak of Serratia marcescens bloodstream infections caused by contamination of prefilled heparin and isotonic sodium chloride solution syringes
Blossom D , Noble-Wang J , Su J , Pur S , Chemaly R , Shams A , Jensen B , Pascoe N , Gullion J , Casey E , Hayden M , Arduino M , Budnitz DS , Raad I , Trenholme G , Srinivasan A , Serratia in Prefilled Syringes Investigation Team . Arch Intern Med 2009 169 (18) 1705-11 BACKGROUND: To investigate clusters of Serratia marcescens (SM) bloodstream infections (BSIs) at health care facilities in several states and determine whether contaminated prefilled heparin and isotonic sodium chloride solution (hereinafter, saline) syringes from a single manufacturer (company X) were the likely cause, we performed an outbreak investigation of inpatient and outpatient health care facilities from October 2007 through February 2008. METHODS: Active case finding for clusters of SM BSIs. Information on SM BSIs was obtained, and SM blood isolates were sent to the Centers for Disease Control and Prevention (CDC). Culture specimens were taken from various lots of prefilled heparin and saline syringes by health care facilities and the CDC to test for the presence of SM. The SM isolates from syringes and blood were compared by pulsed-field gel electrophoresis. RESULTS: A total of 162 SM BSIs in 9 states were reported among patients at facilities using prefilled heparin and/or saline syringes made by company X. Cultures of unopened prefilled heparin and saline syringes manufactured by company X grew SM. Of 83 SM blood isolates submitted to the CDC from 7 states, 70 (84%) were genetically related to the SM strain isolated from prefilled syringes. A US Food and Drug Administration inspection revealed that company X was not in compliance with quality system regulations. CONCLUSIONS: A multistate outbreak of SM BSIs was associated with intrinsic contamination of prefilled syringes. Our investigation highlights important issues in medication safety, including (1) the importance of pursuing possible product-associated outbreaks suggested by strong epidemiologic data even when initial cultures of the suspected product show no contamination and (2) the challenges of medical product recalls when production has been outsourced from one company to another. |
Variability of Burkholderia pseudomallei strain sensitivities to chlorine disinfection
O'Connell HA , Rose LJ , Shams A , Bradley M , Arduino MJ , Rice EW . Appl Environ Microbiol 2009 75 (16) 5405-9 Burkholderia pseudomallei is a select agent and the causative agent of melioidosis. Variations in previously reported chlorine and monochloramine concentration time (Ct) values for disinfection of this organism make decisions regarding the appropriate levels of chlorine in water treatment systems difficult. This study identified the variation in Ct values for 2-, 3-, and 4-log(10) reductions of eight environmental and clinical isolates of B. pseudomallei in phosphate-buffered water. The greatest calculated Ct values for a 4-log(10) inactivation were 7.8 mg.min/liter for free available chlorine (FAC) at pH 8 and 5 degrees C and 550 mg.min/liter for monochloramine at pH 8 and 5 degrees C. Ionic strength of test solutions, culture hold times in water, and cell washing were ruled out as sources of the differences in prior observations. Tolerance to FAC was correlated with the relative amount of extracellular material produced by each isolate. Solid-phase cytometry analysis using an esterase-cleaved fluorochrome assay detected a 2-log(10)-higher level of organisms based upon metabolic activity than did culture, which in some cases increased Ct values by fivefold. Despite strain-to-strain variations in Ct values of 17-fold for FAC and 2.5-fold for monochloramine, standard FAC disinfection practices utilized in the United States should disinfect planktonic populations of these B. pseudomallei strains by 4 orders of magnitude in less than 10 min at the tested temperatures and pH levels. |
- Page last reviewed:Feb 1, 2024
- Page last updated:May 06, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure