Mode of Action and Synergy of Ceftazidime and Baicalein against Streptococcus pyogenes

Purpose: To investigate the antibacterial activity of baicalein used alone, or in combination with ceftazidime, against Streptococcus pyogenes.Methods: Minimum inhibitory concentration (MIC), checkerboard assay parameters, and viability curves were determined for S. pyogenes DMST 30653, 30654, and 30655. Cytoplasmic membrane (CM) permeability technique, enzyme assays, transmission electron microscopy and Fourier transforminfrared microspectroscopy were used to investigate the changes in the bacterial biomolecules.Results: The MIC of ceftazidime and baicalein against all the S. pyogenes strains were 0.50 and > 256.0 μg/ml, respectively. A synergistic effect against these strains was exhibited by the ceftazidime/baicalein combination (fractional inhibitory concentration index, < 0.37). The results for the viable counts indicate that this synergistic activity was present. Baicalein exerted inhibitory activity against β-lactamase. Compared with the controls, combining baicalein with ceftazidime caused peptidoglycan and morphological damage, significantly increased CM permeability and protein concentrations, and decreased cellular fatty acid and nucleic acid concentrations.Conclusion: Baicalein is a potential synergistic adjunct to ceftazidime for the treatment of S. pyogenes infections.Keywords: Streptococcus pyogenes, Cytoplasmic membrane permeability, Baicalein, Ceftazidime, Synergistic activity, Fourier Transform-infrared microspectroscopy, Transmission electron microscop

Cadmium Contamination in Farmland Soil and Water Near Zinc Mining Site

This study was a cross-sectional study conducted in Phatadpadaeng Subdistrict, Mae Sod District, Tak Province, Thailand. This study aimed to determine cadmium concentration in farmland soil and water as well as at the residence of farmers and households. As many as 48 samples of farmers' residence soil and water, twelve samples of households and six samples of farmland soil and eight samples of farmland water were investigated for cadmium concentration using Graphite Furnace Atomic Absorption Spectrophotometer. The Mann-Whitney U test was used for the analysis of the difference of cadmium concentration between farmland soil and residence soil, farmland water and residence water. The results showed no statistically difference among all matrixes, however, farmland soil and farmland water showed highest concentration compared to those of resident farmers and households. The cadmium concentrations in all samples were far below the limit values. This study clearly showed that working conditions of farmers demonstrated higher level of cadmium compared to the living conditions. The cause of this contamination might be from the activities of the surroundings industry. Therefore, it would be recommended that farmers should consider for cadmium exposure while working in farm

Effectiveness of the multidimensional ergonomic intervention model to reduce musculoskeletal discomfort among street sweepers in Chiang Rai Province, Thailand

Kanjanar Pintakham,1,2 Wattasit Siriwong1 1College of Public Health Sciences, Chulalongkorn University, Bangkok, 2School of Health Science, Chiang Rai Rajabhat University, Chiang Rai, Thailand Abstract: The aim of this study was to evaluate the effectiveness of multidimensional ergonomic intervention (MEI) model to reduce musculoskeletal discomfort (MSD) among street sweepers. A quasi-experimental study was conducted in Chiang Rai Province. The MEI model was designed on the basis of four core components: cognitive behavior therapy, ergonomic education training, stretching exercise, and the foam sleeve broom handle grip. Seventy-five street sweepers volunteered for the screening process on MSD of having level score ≥4 by physiotherapist. Face to face interviews were used mainly in order to diagnose MSD. Physical examination was performed by physiotherapist and physical performance by sports scientist. The findings showed that the MEI model among the intervention group significantly reduced MSD compared with that among control group at exit model and follow-up (P<0.01). This research suggests that the MEI model was appropriate to reduce MSD associated with repetitive movement and awkward postures on task. Keywords: repetitive movement, cognitive behavior therapy, stretching exercise, street sweeper

Association between blood cholinesterase activity, organophosphate pesticide residues on hands, and health effects among chili farmers in Ubon Ratchathani Province, northeastern Thailand

Background. Use of pesticides has been documented to lead to several adverse health effects. Farmers are likely to be exposed to pesticides through dermal exposure as a result of mixing, loading, and spraying. Organophosphate pesticides (OPs) are widely used in most of the agricultural areas throughout Thailand. OPs are cholinesterase inhibitors and blood cholinesterase activity is used as a biomarker of OP effects. Objective. This study aims to determine the association between blood cholinesterase activity and organophosphate pesticide residues on chili farmer’s hands and their adverse health effects. Materials and Methods. Ninety chili farmers directly involved with pesticide applications (e.g. mixing, loading, spraying) were recruited and were interviewed face to face. Both enzymes, erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (PChE), were tested with the EQM Test-mate Cholinesterase Test System (Model 400). Hand wipe samples were used for collecting residues on both hands and OP residues for chlorpyrifos and profenofos were quantified using gas chromatography equipped with a flame photometric detector (GC-FPD). Results. The average activity (±SD) of AChE and PChE was 2.73 (±0.88) and 1.58 (±0.56) U/mL, respectively. About 80.0% of the participants had detectable OP residues on hands. The median residues of chlorpyrifos and profenofos were found to be 0.02 and 0.03 mg/kg/two hands, respectively. Half of participants reported having some acute health symptoms within 48 hours after applying pesticides. When adjusted for gender, number of years working in chili farming, and frequency of pesticide use, AChE activity (Adjusted OR = 0.03, 95%CI: 0.01-0.13) and detected OP residues on hands (Adjusted OR = 0.15, 95%CI: 0.02-0.95) were significantly associated with having health effects, but no significant association was found in PChE activity (Adjusted OR = 2.09, 95%CI: 0.63-6.99). Conclusions. This study suggests that regular monitoring for blood cholinesterase and effective interventions to reduce pesticide exposure to prevent health effects should be provided to chili farmers

Investigation of kidney function changes in sea salt workers during harvest season in Thailand

Background. Occupational factors have previously been mentioned as contributing to decreased kidney function and the development of chronic kidney disease of unknown cause. Sea salt workers are one of the occupations facing high outdoor temperatures and a highly, intensive workload. Objective. The purpose of the study was to examine whether the kidney function of sea salt workers at the beginning of the harvest season differs from kidney function at the end of the harvest season and to identify factors that can predict the change of kidney function. Material and methods. Data were collected from salt workers (n=50) who were between 18–60 years of age without hypertension, diabetes, and kidney disease in Samut Sakhon province, Thailand. Urine specific gravity (USG) was used for hydration status and the estimated glomerular filter rate (eGFR) was used to measure kidney function. The mixed model was used to find differences over the harvest season and prediction of factors. Results. On average, the eGFR was estimated to decrease by 15.2 ml/min/1.73 m2 over the harvest season. The decline in eGFR of sea salt workers with moderate and heavy workloads were significantly faster than their light workload counterparts after controlling for other covariates. Similarly, dehydration (USG ≥ 1.030) significantly accelerated the rate of kidney function loss. Conclusions. Our study confirmed exposure to heat over the harvest season leads to decreased eGFR in sea salt workers. The rate of change of eGFR could be predicted by workload and hydration status. Workers with dehydration who performed medium to heavy workloads in farms showed faster kidney function decline than those who performed light workload

Effects of an injury and illness prevention program on occupational safety behaviors among rice farmers in Nakhon Nayok Province, Thailand

Sapsatree Santaweesuk,1,2 Robert S Chapman,1 Wattasit Siriwong1,3 1College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand; 2Srinakarinwirot University Ongkharak Campus, Nakhon Nayok, Thailand; 3Thai Fogarty ITREOH Center, Chulalongkorn University, Bangkok, Thailand Abstract: The objective of this study was to determine the effects of an Injury and Illness Prevention (IIP) program intervention on occupational safety behavior among rice farmers in Nakhon Nayok province, Thailand. This was a quasi-experimental study in an intervention group and a control group. It was carried out in two rice farming communities, in which most people are rice farmers with similar socio-demographic characteristics. Multistage sampling was employed, selecting one person per rice farming household. The intervention group was 62 randomly selected rice farmers living in a rural area; another 55 rice farmers served as the control group. A structured face-to-face interview questionnaire was administered to participants to evaluate their safety behaviors in four areas: equipment use, pesticide use, ergonomics, and working conditions. The 2-week intervention program consisted of four elements: 1) health education, 2) safety inspection, 3) safety communication, and 4) health surveillance. Data were collected at baseline and 4 months after the intervention (follow-up). We used a general linear model repeated-measures analysis of variance to assess the mean difference between baseline and follow-up occupational safety behavior points between the intervention and control groups. Pesticide safety behaviors significantly increased in the intervention group compared with the control group. Ergonomics and working conditions points also increased in the intervention group, but not significantly so. The equipment use score decreased in the intervention group. It is necessary to identify and develop further measures to improve occupational safety behaviors. Some methods, such as effective risk communication, could be added to increase risk perception. Keywords: occupational safety behaviors, rice farmers, safety program, injury and illness prevention progra

Effect of heat exposure on dehydration and kidney function among sea salt workers in Thailand

Background. Excessive heat exposure and dehydration among agricultural workers have been reported to reduce kidney function and lead to chronic kidney disease of unknown etiology (CKDu). Objective. This cross-sectional study aimed to assess heat exposure, factors related to dehydration and the relationship between dehydration and biomarkers of kidney function among sea salt workers in Thailand. Material and methods. Wet bulb globe temperature (WBGT) was used at the time workers started work outdoors on salt farms. Urine-specific gravity, urine osmolarity, and serum creatinine were collected from 50 workers after work. Results. The results showed that more than 50% of the participants were dehydrated after work. The maximum hours spent working per day was 10. The average water intake was 1.51 L. Urine specific gravity was highly significant correlated with urine osmolality (rs = 0.400, p<0.01), and urine osmolality was significantly correlated with the estimated glomerular filtration rate (eGFR) (rs = 0.349, p<0.05). In bivariate analysis adjusted for age, sex, and current alcohol consumption, we found that a WBGTTWA ≥ 30°C (OR = 0.08, 95% CI = 0.01-0.44, p = 0.003) and hours spent working (OR=2.22, 95% CI = 1.42-3.47, p <0.001) were independently associated with dehydration. This suggests that workers should increase their time spent on breaks and increase water consumption. Conclusions. Educational program on heat exposure and heat-related illness prevention strategies should be provided

Environmental arsenic exposure and risk of diabetes type 2 in Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand: unmatched and matched case&ndash;control studies

Kwanyuen Sripaoraya,1,2 Wattasit Siriwong,1 Sumol Pavittranon,2 Robert S Chapman1 1College of Public Health Sciences, Chulalongkorn University, Bangkok, 2Medical Life Sciences Institute, Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand Background: There are inconsistent findings on associations between low-to-moderate level of arsenic in water and diabetes risk from previous epidemiological reports. In Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand, a low level of arsenic exposure among population was observed and increased diabetes mellitus (DM) rate was identified.Objectives: We aimed to investigate the association between determinants (including low-level water arsenic exposure) of DM type 2 risk among residents of three villages of Ron Phibun subdistrict, Nakhon Si Thammarat Province.Materials and methods: Secondary data from two previous community based-studies, conducted in 2000 and 2008, were utilized. Data on independent variables relating to arsenic exposure and sociodemographic characteristics were taken from questionnaires and worksheets for health-risk screening. Water samples collected during household visit were sent for analysis of arsenic level at certified laboratories. Diabetes cases (N=185) were those who had been diagnosed with DM type 2. Two groups of controls, one unmatched to cases (n=200) and one pair matched on age and gender (n=200), were selected for analysis as unmatched and matched case&ndash;control studies, respectively. A multiple imputation technique was used to impute missing values of independent variables. Multivariable logistic regression models, with independent variables for arsenic exposure and sociodemographic characteristics, were constructed. The unmatched and matched data sets were analyzed using unconditional and conditional logistic analyses, respectively.Results: Older age, body mass index (BMI), having a history of illness in siblings and parents, and drinking were associated with increased DM type 2 risk. We found no convincing association between DM type 2 risk and water arsenic concentration in either study.Conclusion: We did not observe meaningful association between diabetes risk and the low-to-moderate arsenic levels observed in this study. Further research is needed to confirm this finding in the study area and elsewhere in Thailand. Keywords: diabetes, arsenic exposure, case&ndash;control, Ron Phibun subdistrict, Thailan

Multi-approach model for improving agrochemical safety among rice farmers in Pathumthani, Thailand

Buppha Raksanam,1,2 Surasak Taneepanichskul,2 Wattasit Siriwong,2 Mark Robson3,41Sirindhorn College of Public Health, Trang, 2College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand; 3School of Environmental and Biological Sciences, Rutgers University, 4School of Public Health, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ, USAAbstract: The large-scale use of agrochemicals has raised environmental and human health concerns. A comprehensive intervention strategy for improving agrochemical safety among rice farmers in Thailand is lacking. The objective of this study is to develop a model in order to improve farmers&amp;rsquo; health and prevent them from being exposed to agrochemical hazards, in addition to evaluating the effectiveness of the intervention in terms of agrochemical safety. This study was conducted between October 2009 and January 2011. It measures changes in the mean scores of agrochemical knowledge, health beliefs, agrochemical use behaviors, and in-home pesticide safety. Knowledge of agrochemical use constitutes a basic knowledge of agrochemicals and agrochemical safety behaviors. Health beliefs constitute perceived susceptibility, severity, benefits, and barriers to using agrochemicals. Agrochemical use behaviors include self-care practices in terms of personal health at specific times including before spraying, while spraying, during storage, transportation, waste management, and health risk management. Fifty rice farmers from Khlong Seven Community (study group) and 51 rice farmers from Bueng Ka Sam community (control group) were randomly recruited with support from community leaders. The participants were involved in a combination of home visits (ie, pesticide safety assessments at home) and community participatory activities regarding agrochemical safety. This study reveals that health risk behaviors regarding agrochemical exposure in the study area are mainly caused by lack of attention to safety precautions and the use of faulty protective gear. After 6 months, the intervention program showed significant improvements in the overall scores on knowledge, beliefs, behaviors, and home pesticide safety in the study group (P &amp;lt; 0.05). Therefore, this intervention model is effective in improving agrochemical safety behaviors among Khlong Seven Community rice farmers. These findings demonstrate that a multi-approach model for improving agrochemical safety behaviors can lead to sustainable prevention of agrochemical hazards for farmers.Keywords: rice farmer, agrochemical safety, community-based intervention, mode