The Abundance of Plasmid-Mediated Quinolone Resistance Genes in Enterobacter cloacae Strains Isolated from Clinical Specimens in Kermanshah, Iran

Background

Enterobacter cloacae (E. cloacae) is one of the most common Enterobacteriaceae causing nosocomial infections. Plasmid-mediated quinolone resistance (PMQR) determinants have been considered recently. This study evaluated the abundance of PMQR genes in strains of E. cloacae obtained from clinical samples in Kermanshah, Iran.

Methods

In this descriptive cross-sectional study, after collecting 113 isolates of E. cloacae, their identity was confirmed using specific biochemical tests. After determining their drug resistance patterns using disc diffusion, the phenotypic frequency of extended-spectrum beta-lactamase (ESBL)-producing isolates was measured by the double-disk synergy test (DDST) method. The isolates were examined for the presence of qnrA, qnrB, qnrS, and aac(6')-Ib-cr genes by the polymerase chain reaction (PCR) assay.

Results

The antibiotic resistance rate of E. cloacae isolates varied from 9.7% to 60.2%; among them, 78% were multidrug-resistant (MDR). The highest quinolone resistance was observed in ESBL-producing strains of E. cloacae. The frequency of positive isolates for PMQR and ESBL was 79.6% and 57.5%, respectively. The genes aac(6')-ib-cr (70.8%) and qnrB (38.1%) had the highest frequency among other genes. The number of isolates simultaneously carrying 2 and 3 genes was 64 and 5 isolates, respectively.

Conclusion

The obtained results indicate a high degree of quinolone resistance among ESBL-producing E. cloacae strains. Nevertheless, there was a significant relationship between the PMQR gene and ESBL-positive isolates. Therefore, special attention should be paid to molecular epidemiological studies on antibiotic resistance to quinolones and beta-lactamases in these strains.

Evaluation of different drying processes by energy consumption in an insulated and not insulated laboratory convection dryer

Drying is a process to increase the shelf-life of fruits by decreasing their water content. It is one of the energy consuming processes in food engineering. In many studies, the drying time duration and quality of dried fruits were investigated. In this study, the energy consumption in different drying conditions was investigated for the apple in a laboratory convection dryer. The drying conditions were the application of the temperatures of 40, 50, and 60°C and the speeds of 0.5 and 1 ms-1 for the drying air using the insulated and non-insulated drying chambers. Independent from drying duration, the highest energy consumption was recorded as 11.2 kWh for the non-insulated dryer under the drying air condition of 40°C and 0.5 ms-1 . While the lowest energy consumption was only 5.8 kWh for the insulated dryer with the drying air condition of 40 and 50°C and the same 0.5 ms-1 . The drying duration for these conditions was 537, 313, and 233 mins. To achieve the shortest drying time (153 mins), the condition of 60°C and 1 ms-1 in the insulated dryer was used which caused the energy consumption of 7.2 kWh.

An easy method to modify PEDOT:PSS/perovskite interfaces for solar cells with efficiency exceeding 15%

Surface treatment of PEDOT:PSS films using propionic acid (PA) leads to better device performance for the resulting CH₃NH₃PbI₃ perovskite solar cells (PCE > 15%).