Antimicrobial resistance genes are enriched in aerosols near impacted urban surface waters in La Paz, Bolivia.

Antibiotic resistance poses a major global health threat. Understanding emergence and dissemination of antibiotic resistance in environmental media is critical to the design of control strategies. Because antibiotic resistance genes (ARGs) may be aerosolized from contaminated point sources and disseminated more widely in localized environments, we assessed ARGs in aerosols in urban La Paz, Bolivia, where wastewater flows in engineered surface water channels through the densely populated urban core. We quantified key ARGs and a mobile integron (MI) via ddPCR and E. coli spp. as a fecal indicator by culture over two years during both the rainy and dry seasons in sites near wastewater flows. ARG targets represented major antibiotic groups-tetracyclines (tetA), fluoroquinolines (qnrB), and beta-lactams (blaTEM)-and an MI (intI1) represented the potential for mobility of genetic material. Most air samples (82%) had detectable targets above the experimentally determined LOD: most commonly blaTEM and intI1 (68% and 47% respectively) followed by tetA and qnrB (17% and 11% respectively). ARG and MI densities in positive air samples ranged from 1.3 × 101 to 6.6 × 104 gene copies/m3 air. Additionally, we detected culturable E. coli in the air (52% of samples <1 km from impacted surface waters) with an average density of 11 CFU/m3 in positive samples. We observed decreasing density of blaTEM with increasing distance up to 150 m from impacted surface waters. To our knowledge this is the first study conducting absolute quantification and a spatial analysis of ARGs and MIs in ambient urban air of a city with contaminated surface waters. Environments in close proximity to urban wastewater flows in this setting may experience locally elevated concentrations of ARGs, a possible concern for the emergence and dissemination of antimicrobial resistance in cities with poor sanitation.

Detection and assessment of the antibiotic resistance of Enterobacteriaceae recovered from bioaerosols in the Choqueyapu River area, La Paz - Bolivia.

As a highly contaminated waterway flowing through a densely populated urban area, microbiological pollution associated with the Choqueyapu River and the absence of a wastewater treatment plant in La Paz city threatens public health. We collected air samples adjacent to this river using impingement. Laboratory analyses identified the presence of Enterobacteriaceae, reporting a maximum concentration of 86,11 CFU/m3 of sampled air. Positive samples were tested for antibiotic susceptibility against the antibiotics amoxicillin-clavulanic acid, ciprofloxacin, gentamicin, meropenem, sulfamethoxazole-trimethoprim and tetracycline via disk diffusion. The highest percentages of antibiotic resistance were registered for tetracycline (50% of isolates) and sulfamethoxazole-trimethoprim (38,9%), while the lowest resistance profile was reported for meropenem (5,6%). A comparison of results obtained on the pilot studies [elaborated during the wet season of 2018 by Chavez, 2019 and Salazar et al., 2020] and the present study has been done, highlighting seasonal effects over airborne Enterobacteriaceae concentration. Also, it was determined an increase of antibiotic resistance for tetracycline, gentamicin and ciprofloxacin; and a reduction for sulfamethoxazole-trimethoprim, meropenem and amoxicillin-clavulanic acid.

Bioaerosol sampling optimization for community exposure assessment in cities with poor sanitation: A one health cross-sectional study.

Evidence of exposure to enteric pathogens through the air and associated risk of infection is scarce in the literature outside of animal- or human-waste handling settings. Cities with poor sanitation are important locations to investigate this aerial exposure pathway as their rapid growth will pose unprecedented challenges in waste management. To address this issue, simple surveillance methods are needed. Therefore, the objectives of this study were to optimize a community exposure bioaerosol surveillance strategy for urban outdoor locations with poor sanitation, and to determine which bioaerosols could contribute to exposure. Passive and active bioaerosol sampling methods were used to characterize the fate and transport of sanitation-related bioaerosols during the rainy and dry seasons in La Paz, Bolivia. Median coliform bacteria fluxes were 71 CFU/(m2 × h) during the rainy season and 64 CFU/(m2 × h) during the dry season, with 38% of the dry season samples testing positive for E. coli. Wind speed, relative humidity and UVB irradiance were identified as significant covariates to consider in bioaerosol transport models in La Paz. Active sampling yielded one positive sample (10%) for human adenovirus (HadV) and one sample (10%) for influenza A virus during the rainy season. HadV was detected at the site with the highest bacterial flux. Four samples (8%) were positive for influenza A virus in the dry season. These findings suggest that aerosols can contribute to community exposure to potentially pathogenic microorganisms in cities with poor sanitation. The use of passive sampling, despite its limitations, can provide quantitative data on microorganisms' viability within realistic timeframes of personal exposure.

Assessment of antibiotic resistant coliforms from bioaerosol samples collected above a sewage-polluted river in La Paz, Bolivia.

Antimicrobial resistance is a global health risk, and the presence of resistant bacteria in the environment may be an indicative of fecal pollution. The objective of this study has been to assess the antibiotic resistance of airborne coliforms near a highly impacted urban river that may contain high levels of fecal waste. The pilot study has been located within an Andean river basin, the Choqueyapu River basin, which flows through La Paz city in Bolivia. Bioaerosol samples have been collected using liquid impingement and plated on mTEC agar. Coliforms have been detected within 80% of the air samples. The resistance profiles of coliforms present in 20 air samples have been determined by using a modified Kirby-Bauer disk diffusion test against amoxicillin-clavulanic acid, ciprofloxacin, gentamicin, meropenem, sulfamethoxazole-trimethoprim, and tetracycline, antibiotics commonly used to treat gram-negative infection. Broad patterns of antibiotic resistance have been observed throughout the study, with coliforms from at least one sample exhibiting resistance to each of the tested antibiotics. Resistance to sulfamethoxazole and amoxicillin-clavulanic acid has been the most commonly observed, with coliforms in 73% and 60% of samples which helps to demonstrate resistance to these antibiotics, respectively. This study provides insight into the prevalence of airborne, antibiotic resistant coliforms near concentrated fecal waste streams and this highlights an underappreciated hazard and the potential exposure risk in areas where fecal waste may become aerosolized at any given time.

Beliefs and Determinants of Use of Traditional Complementary/Alternative Medicine in Pediatric Patients Who Undergo Treatment for Cancer in South America.

Purpose The use of traditional complementary/alternative medicine (TCAM) among children with cancer has been well documented. South America has a rich history of traditional healers and medicinal resources; however, little is known about the use of TCAM among children with cancer. We sought to investigate patterns, beliefs, and determinants of TCAM use among South American children with cancer. Methods A cross-sectional survey was administered to 199 children treated for cancer at institutions located in Buenos Aires, Argentina, and Montevideo, Uruguay. Participants were queried about the type of TCAM and strength of beliefs associated with its use. Logistic regression analysis was used to estimate the odds ratios with 95% CIs. Results We found that the use of TCAM was common in both Argentina (47%) and Uruguay (76%). Variations in the forms of TCAM used were observed between the countries; however, both countries used TCAM primarily for supportive care. Mother's education, wealth index, and TCAM belief system were significant predictors of TCAM. Conclusion To our knowledge, this study is the first to report on the use of TCAM in pediatric oncology in South America. The study identifies several predictors of TCAM use, which may serve as target variables for educational and research initiatives. The finding that most families use TCAM for supportive care suggests that future efforts could evaluate the role of TCAM to enhance existing supportive care regimens, particularly in settings where access to conventional medications are limited.

Analysis of semicarbazide in baby food by liquid chromatography tandem mass spectrometry (LC-MS-MS)--in-house method validation.

A method for detection of semicarbazide (SEM) in baby food was validated. SEM was extracted with hydrochloric acid and derivatised with 2-nitrobenzaldehyde, using [15N2,13C] semicarbazide as internal standard. The extract was neutralised, purified on a solid phase extraction cartridge and SEM was determined by reversed phase LC-MS-MS. Linearity was demonstrated in the ranges from 0.1 ng ml(-1) to 1 ng ml(-1) and from 2 ng ml(-1) to 80 ng ml(-1). Matrix effects were non significant for meat-based and significant for apple and rice-based baby foods, in both ranges. Mean recoveries ranged from 87.8% to 107.2% with relative standard deviation from 0.2% to 9.1%, considering both ranges. Limits of detection and quantification were 0.1 microg kg(-1) and 0.25 microg kg(-1), respectively. The results of the validation process demonstrated the method suitability for use in food control.