Growth and no-growth boundary of Clostridium perfringens in cooked cured meats - A logistic analysis and development of critical control surfaces using a solid growth medium.

This study was conducted to evaluate the effect of sodium nitrite (NaNO2, 100-200 ppm), sodium erythorbate (SE, 0-547 ppm), sodium tripolyphosphate (STPP, 0-0.5 %), and sodium chloride (NaCl, 2-3 %) on growth of C. perfringens using a solid growth medium and to develop a growth/no-growth boundary (critical control surface, or CCS) to prevent its growth in cooked cured meat under the optimal temperature condition. Melted Shahidi Ferguson Perfringens (SFP) agar, inoculated with a 3-strain spore cocktail and mixed with NaNO2, SE, STPP, and NaCl according to a Box-Behnken response surface experimental design, was dispersed in 96-well microplates and incubated anaerobically in an incubator programmed to remain at 4 °C for 24 h, heat to 80 °C in 1.75 h, quickly (0.5 h) cool to 46 °C (optimum temperature), and then maintain at 46 °C overnight. The plates were examined optically and visually for colony formation. Any well free of growth was designated as no-growth. Logistic regression was used to analyze the growth probability (P) as affected by NaNO2, SE, STPP, and NaCl and define a CSS as meeting the criterion of P < 1/96. The results showed that STPP and the interactions of SE with NaNO2 and NaCl could reduce the growth probability of C. perfringens in SFP agar. The validation of CCS with ground beef showed an accuracy of 96.3 % for no growth of C. perfringens in the inoculated samples. The results of this study proved that cured meat can be formulated with proper combinations of NaNO2, SE, STPP, and NaCl to prevent the growth of C. perfringens even under the optimum temperature condition, thus preventing food poisoning caused by the growth of this microorganism.

Bayesian modeling of maternal mortality in Ghana.

Maternal mortality is a critical measure for quality of health system in any country and hence many countries have made concerted efforts to check its occurrence. Various stakeholders involved in the management of health system in Ghana have been tasked to ensure women do not die whilst giving birth. This study was conducted on a sample of 1,052 women selected from all the ten administrative regions of Ghana in which 188 maternal deaths occurred. Bayesian logistic modeling was used. Age at death, marital status, age, season, region, place of death, place of residence, religion and ethnicity emerged as the most significant determinants of maternal mortality in Ghana. It was realized that high numbers of maternal deaths were recorded in the least developed regions in the northern region. It is therefore important for stakeholders to devise a road map of getting health workers to accept postings to the rural areas and also provide well resourced health facilities to stem this menace.

Exploring thresholds and interaction effects among antibiotic usage, covariates, and their effect on antibiotic resistance using an extended-spectrum ß-Lactamase-producing Klebsiella pneumoniae case.

BACKGROUND: This study was aimed to explore thresholds with interaction effects among antibiotic usage, covariates (alcohol-based hand rub (ABHR)), and their effect on extended-spectrum ß-lactamase-producing Klebsiella pneumoniae (ESBL-producing K. pneumoniae) in hospitalized patients. METHODS: Multivariate Adaptive Regression Spline models were used. These considered second-order interactions among antibiotic use and ABHR in addition to potential thresholds that further improve explained variance in the ESBL-producing K. pneumoniae response. The study involved collecting monthly hospital-level data for January 2017-December 2021. RESULTS: Analysis of the main effects showed that third-generation cephalosporins above 2.00 DDD/100 occupied bed days (OBD) generally increased ESBL-producing K. pneumoniae incidence (cases/100 OBD). Levels of ABHR above 6.61 L/100 OBD were shown to generally decrease ESBL-producing K. pneumoniae incidence. Second-order interactions revealed that when third-generation cephalosporin use was greater than 3.71 DDD/100 OBD, and ABHR was greater than 6.6 L/100 OBD (same as main effect threshold), ABHR partially lost effectiveness in its ability to reduce ESBL-producing K. pneumoniae incidence. This demonstrates the importance of not exceeding the identified thresholds of 3.71 DDD/100 OBD for third-generation cephalosporin use. CONCLUSION: The main-effect thresholds in third-generation cephalosporins and ABHR, and the identified interaction between third-generation cephalosporins and ABHR can inform effective hospital antimicrobial stewardship.

Advanced statistics identification of participant and treatment predictors associated with severe adverse effects induced by fluoropyrimidine-based chemotherapy.

PURPOSE: Adverse effects following fluoropyrimidine-based chemotherapy regimens are common. However, there are no current accepted diagnostic markers for prediction prior to treatment, and the underlying mechanisms remain unclear. This study aimed to determine genetic and non-genetic predictors of adverse effects. METHODS: Genomic DNA was analyzed for 25 single nucleotide polymorphisms (SNPs). Demographics, comorbidities, cancer and fluoropyrimidine-based chemotherapy regimen types, and adverse effect data were obtained from clinical records for 155 Australian White participants. Associations were determined by bivariate analysis, logistic regression modeling and Bayesian network analysis. RESULTS: Twelve different adverse effects were observed in the participants, the most common severe adverse effect was diarrhea (12.9%). Bivariate analysis revealed associations between all adverse effects except neutropenia, between genetic and non-genetic predictors, and between 8 genetic and 12 non-genetic predictors with more than 1 adverse effect. Logistic regression modeling of adverse effects revealed a greater/sole role for six genetic predictors in overall gastrointestinal toxicity, nausea and/or vomiting, constipation, and neutropenia, and for nine non-genetic predictors in diarrhea, mucositis, neuropathy, generalized pain, hand-foot syndrome, skin toxicity, cardiotoxicity and fatigue. The Bayesian network analysis revealed less directly associated predictors (one genetic and six non-genetic) with adverse effects and confirmed associations between six adverse effects, eight genetic predictors and nine non-genetic predictors. CONCLUSION: This study is the first to link both genetic and non-genetic predictors with adverse effects following fluoropyrimidine-based chemotherapy. Collectively, we report a wealth of information that warrants further investigation to elucidate the clinical significance, especially associations with genetic predictors and adverse effects.

Identifying Antibiotic Use Targets for the Management of Antibiotic Resistance Using an Extended-Spectrum ß-Lactamase-Producing Escherichia coli Case: A Threshold Logistic Modeling Approach.

The aim of this study was to develop a logistic modeling concept to improve understanding of the relationship between antibiotic use thresholds and the incidence of resistant pathogens. A combined approach of nonlinear modeling and logistic regression, named threshold logistic, was used to identify thresholds and risk scores in hospital-level antibiotic use associated with hospital-level incidence rates of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (E. coli). Threshold logistic models identified thresholds for fluoroquinolones (61.1 DDD/1000 occupied bed days (OBD)) and third-generation cephalosporins (9.2 DDD/1000 OBD) to control hospital ESBL-producing E. coli incidence. The 60th percentile of ESBL-producing E. coli was determined as the cutoff for defining high incidence rates. Threshold logistic analysis showed that for every one-unit increase in fluoroquinolones and third-generation cephalosporins above 61.1 and 9.2 DDD/1000 OBD levels, the average odds of the ESBL-producing E. coli incidence rate being ≥60th percentile of historical levels increased by 4.5% and 12%, respectively. Threshold logistic models estimated the risk scores of exceeding the 60th percentile of a historical ESBL-producing E. coli incidence rate. Threshold logistic models can help hospitals in defining critical levels of antibiotic use and resistant pathogen incidence and provide targets for antibiotic consumption and a near real-time performance monitoring feedback system.

Social capital and self-rated health among middle-aged and older adults in China: a multilevel analysis.

This study examined the association between social capital, at both the individual and the community level, and self-rated health among older adults in China. Using data from the 2008 Pilot Survey of China Health and Retirement Longitudinal Study, a series of multilevel logistic models were estimated in SAS 9.2. The association between social capital and self-rated health was examined among 996 adults aged 45 or older from two provinces in China, while controlling for demographic characteristics and socioeconomic variables. Our results suggest the significant association between certain aspects of social capital, at both the individual and the community level, and self-rated health. The individual-level social capital in the form of perceived help in the future and the social capital of community in the form of the availability of amenities and associations within the community were significantly related to self-rated health. A significant cross-level interaction effect between individual- and community-level social capital was also observed.