Begum Maslak

The purpose of the study was to examine the prevalence of Escherichia coli in shrimps and mussels, and to determine the distribution of β-lactam, aminoglycoside, quinolone, and multi-drug resistance phenotypically and genotypically in E. coli isolates obtained from mussels and shrimps in Istanbul. Faecal samples were collected from mussels (n = 96) and shrimps (n = 96) from the Marmara Sea coastline and fish markets in Istanbul. For the detection of antibiotic susceptibilities, seven antibiotic groups were used. β-lactamase, aminoglycoside, and quinolone genes were also determined. A total of 34 (17.7%, 15 shrimps, and 19 mussels) E. coli were isolated, and 17 (50%) were found to be resistant to one or more antimicrobials. The highest resistance was seen against aminoglycosides with 11 isolates (32.35%), followed by quinolones with 10 isolates (29.41%) and extended-spectrum β-lactamase (ESBL) with 4 isolates (11.76%). Multi-drug resistance was detected in 5 isolates (14.7%) from 3 shrimp and 2 mussel samples. The prevalence of ESBL genes was demonstrated at 3.84% in mussels and shrimp samples. There were no AmpC and carbapenemase-producing genes. These samples harbored bla_CTX-M-1 (n = 3) and bla_TEM (n = 4). Ten isolates were resistant to aminoglycosides genotypically. Resistance genes detected were strB in 2 isolates, aadA in 5, strB and aadA together in 3, ANT('')-Ia, aphA1 and aphA2 simultaneously in 3, aphA1 in 1, aac(3)-IIa in 1 isolate. aac(6')-Ib-cr gene was detected in only one of 10 phenotypically resistant isolates to quinolones.

The study investigated the concentration and distribution features of culturable airborne fungi (CAF) in indoor air for four public transport vehicles (bus, metro, metrobus, and ferry) in Istanbul. The collection of indoor air samples was performed from each transport vehicle in both directions once a month from March 2017 to February 2018. The highest and lowest CAF concentrations measured during the study were determined to be 40–660 CFU/m³ in bus, 20–400 CFU/m³ in metro, 40–360 CFU/m³ in metrobus, and 20–260 CFU/m³ in ferry. It was determined that no fungal colonies were observed on the ferry on the inbound route in March. The findings demonstrated that CAF concentrations in bus were higher compared to the indoor air in other transport vehicles, and there was a significant correlation between fungal levels and the number of passengers (p < 0.05; r = 0.68) and RH% (p < 0.05; r = 0.43). In line with the density order of fourteen fungal species determined, Penicillium spp., Paecilomyces spp., and Aspergillus spp. were identified. The results of this study also showed that there were high levels of fungi in public transport vehicles that could affect human health in many sampling periods. Many countries are trying to or have established their national ambient air quality standards, following the WHO Air Quality Guidelines. Unfortunately, Turkey does not have official standards for indoor air quality (IAQ). Therefore, monitor, control, and maintenance of IAQ-related research in such public transport vehicles in Turkey are necessary as much as development of standards related to it.