Molecular epidemiology and mechanisms of carbapenem and colistin resistance in Klebsiella and other Enterobacterales from treated wastewater in Croatia.

Among the most problematic bacteria with clinical relevance are the carbapenem-resistant Enterobacterales (CRE), as there are very limited options for their treatment. Treated wastewater can be a route for the release of these bacteria into the environment and the population. The aim of this study was to isolate CRE from treated wastewater from the Zagreb wastewater treatment plant and to determine their phenotypic and genomic characteristics.

Prevalence of enteric opportunistic pathogens and extended-spectrum cephalosporin- and carbapenem-resistant coliforms and genes in wastewater from municipal wastewater treatment plants in Croatia.

Extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacterales are a critical global health problem and wastewater treatment plants (WWTPs) can promote their spread into the environment; yet their efficacy is not well characterized. Here, we have used conventional culturing to monitor coliform bacteria and quantitative PCR to monitor 2 ESBL and 5 carbapenemase (CP) genes and 4 enteric opportunistic pathogens (EOPs) in the influent and effluent of 7 Croatian WWTPs in two seasons. In general, levels of total, cefotaxime- and carbapenem-resistant coliforms were significantly reduced but not eliminated by conventional treatment in most WWTPs.

Characterization of macrolide resistance in bacteria isolated from macrolide-polluted and unpolluted river sediments and clinical sources in Croatia.

Environments polluted with excessively high levels of antibiotics released from manufacturing sites can act as a source of transferable antibiotic resistance (AR) genes to human commensal and pathogenic bacteria. The aim of this study was to evaluate AR of bacteria isolated from the Sava river sediments (Croatia) at the discharge site of effluents from azithromycin production compared to those from the upstream site and isolates collected in Croatian hospitals. A total of 228 environmental strains of azithromycin-resistant bacteria were isolated and identified, with 124 from the discharge site and 104 from the upstream site.

A global multinational survey of cefotaxime-resistant coliforms in urban wastewater treatment plants.

The World Health Organization Global Action Plan recommends integrated surveillance programs as crucial strategies for monitoring antibiotic resistance. Although several national surveillance programs are in place for clinical and veterinary settings, no such schemes exist for monitoring antibiotic-resistant bacteria in the environment. In this transnational study, we developed, validated, and tested a low-cost surveillance and easy to implement approach to evaluate antibiotic resistance in wastewater treatment plants (WWTPs) by targeting cefotaxime-resistant (CTX-R) coliforms as indicators.

Lipid Composition of M12 Strain Grown on Glycerol as a Carbon Source.

Research Background: In this study the content and composition of lipids in ergosterol-reduced M12 strain grown on glycerol as a carbon source is determined. Blocking the ergosterol synthesis route in yeast cells is a recently proposed method for increasing -adenosyl-l-methionine (SAM) production.

Experimental Approach: The batch cultivation of M12 yeast was carried out under aerobic conditions in a laboratory bioreactor with glycerol as carbon source, and with pulsed addition of methionine.

Effect of Thermosonication and Physicochemical Properties of Wine on Culturability, Viability, and Metabolic Activity of Yeast in Red Wines.

The aim of this research was to investigate the short- and long-term effects of thermosonication and different physicochemical properties of wine on culturability, viability, and metabolic activity of yeast. Thermosonication was conducted at 43 °C during 1, 2, and 3 min, while wine variations included several pH, alcohol, and sugar levels. Cell culturability and viability were determined immediately after treatment and during 90 days of storage, while metabolic activity was determined after 90 days of storage.

Characterization of a S-adenosyl-l-methionine (SAM)-accumulating strain of Scheffersomyces stipitis.

S-adenosyl-l-methionine (SAM) is an important molecule in the cellular metabolism of mammals. In this study, we examined several of the physiological characteristics of a SAM-accumulating strain of the yeast Scheffersomyces stipitis (M12), including SAM production, ergosterol content, and ethanol tolerance. S.