Legionellosis in Poland in 2018-2021.

Objectives: The aim of this study is to compare the epidemiological situation of legionellosis in Poland in 2018-2021 to prior years, taking into account the impact of the COVID-19 pandemic in 2020-2021. Material and methods: The assessment is based on national surveillance data published in the annual bulletin "Infectious Diseases and Poisons in Poland" from 2013 to 2021, as well as data from Legionnaires' disease case reports collected and sent to the Department of Epidemiology of Infectious Diseases and Surveillance NIPH NIH - NRI by sanitary and epidemiological stations or submitted to EpiBase. Results: In Poland, both Legionnaires' disease (an acute infection that progresses to pneumonia) and Pontiac fever (a mild, flu-like sickness) are reported. In 2018-2021, a total of 255 cases of legionellosis were registered, including 236 cases of Legionnaires' disease and 19 cases of Pontiac fever. Each year, there was an increase in the number of notifications compared to the annual median number of cases from 2013-2017. The annual incidence rate in 2019 (0.23 per 100,000 population) was the highest since the start of legionellosis case registration in Poland. It declined again during the years of the COVID-19 pandemic. The notifications occurred throughout the country, but the highest notification rate was observed in the western belt of voivodeships. Pomorskie reported the highest incidence, accounting for more than 20% of all registered cases. The median incidence of Legionnaires' disease in men (0.23 per 100,000) was more than twice that of women (0.10), with the highest incidence (0.58) recorded in men 65 years of age or older. All indigenous cases of Legionnaires' disease were sporadic; all but three patients were hospitalized. State Sanitary Inspection reported 26 fatal cases of Legionnaires' disease (mortality = 11%). Twenty-four cases were linked to contaminated water systems in health-care settings, and 21 cases were likely associated with travel abroad. Summary and conclusions: Although the number of notifications has increased in recent years, Legionnaires' disease is still an infrequently diagnosed respiratory infection in Poland, and the reported incidence remains one of the lowest in the entire EU. The most affected demographic group is men aged 65 and older. Improving the early diagnosis of Legionnaires' disease in healthcare settings remains a priority.

Comparative evaluation of mutagenic, genotoxic, cytotoxic, and antimicrobial effects of flavour and fragrance aldehydes, ketones, oximes, and oxime ethers.

Despite the large number of odoriferous compounds available, new ones with interesting olfactory characteristics are desired due to their potentially high commercial value. Here, we report for the first time mutagenic, genotoxic, and cytotoxic effects, and antimicrobial properties of low-molecular fragrant oxime ethers, and we compare their properties with corresponding oximes and carbonyl compounds. 24 aldehydes, ketones, oximes, and oxime ethers were evaluated for mutagenic and cytotoxic effects in Ames (using Salmonella typhimurium strains TA 98 with genotype hisD3052, rfa, uvrB, pKM101, and TA100 with genotype hisG46, rfa, uvrB, pKM101, concentration range: 0.0781-40 mg/mL) and MTS (using HEK293T cell line concentration of tested substances: 0.025 mM) assays. Antimicrobial evaluation was carried out against Bacillus cereus (ATCC 10876), Staphylococcus aureus (ATCC 6538), Enterococcus hirae (ATCC 10541), Pseudomonas aeruginosa (ATCC 15442), Escherichia coli (ATCC 10536), Legionella pneumophila (ATCC 33152); Candida albicans (ATCC 10231) and Aspergillus brasiliensis (ATCC 16404) with concentration range of tested substances 9.375 - 2.400 mg/mL. Furthermore, 5 representatives of carbonyl compounds, oximes, and an oxime ether (stemone, buccoxime, citral, citral oxime, and propiophenone oxime O-ethyl ether) were evaluated for genotoxic properties in SOS-Chromotest (concentration range: 7.8·10-5 - 5·10-3 mg/mL). All of the tested compounds did not exhibit mutagenic, genotoxic, or cytotoxic effects. Oximes and oxime ethers showed relevant antimicrobial activity against pathogenic species (P. aeruginosa, S. aureus, E.coli, L. pneumophila, A. brasiliensis, C. albicans) in the MIC range 0.075 - 2.400 mg/mL compared to the common preservative methylparaben with the MIC range 0.400-3.600 mg/mL. Our study shows that oxime ethers have the potential to be used as fragrant agents in functional products.

The Mechanisms Involved in the Fluoroquinolone Resistance of Salmonella enterica Strains Isolated from Humans in Poland, 2018-2019: The Prediction of Antimicrobial Genes by In Silico Whole-Genome Sequencing.

Salmonellosis remains the second most common zoonosis in Europe. Resistance to fluoroquinolones (FQs) in Salmonella has been increasing worldwide, with WHO considering FQ-resistant Salmonella spp. as high-priority pathogens. The aim of this study was a retrospective analysis of the molecular mechanisms of FQ resistance, detected among clinical ciprofloxacin-resistant Salmonella enterica belonging to the most common serotypes. The whole genome sequences (WGS) of tested isolates were also analysed for the occurrence of other antimicrobial resistance determinants. Out of a total of 1051 Salmonella collected in the years 2018-2019, 447 strains belonging to the most common serotypes in Poland were selected were screened for FQ resistance using the pefloxacin disc test according to EUCAST recommendations. All pefloxacin-resistant isolates were confirmed as ciprofloxacin-resistant using the E-test. A total of 168 (37.6%) Salmonella enterica, which belonged to seven serotypes, were resistant to ciprofloxacin (mostly Hadar, Virchow and Newport). A hundred randomly selected Salmonella were investigated by WGS. A total of 127 QRDR mutations in GyrA and ParC were identified in 93 isolates. The qnr genes were the only PMQR determinants detected and were found in 19% of the sequenced isolates. Moreover, 19 additional resistance genes (including: bla,,tet, sul, aad, aac-, ant-, aph-, floR, cmlA) were identified among the FQ-resistant Salmonella tested that confer resistance to clinically important antibiotics such as ß-lactams, tetracyclines, sulphonamides, aminoglycosides and phenicol, respectively). In conclusion, FQ resistance of human Salmonella in Poland is rising towards a critical level and needs to be tightly monitored.

Prevalence of Plasmid-Mediated Quinolone Resistance (PMQRs) Determinants and Whole Genome Sequence Screening of PMQR-Producing E. coli Isolated from Men Undergoing a Transrectal Prostate Biopsy.

Fluoroquinolones (FQs) are recommended as prophylaxis for men undergoing transrectal prostate biopsy (TRUS-Bx). Recent studies suggest a significant share of FQ-resistant rectal flora in post-TRUST-Bx infections. METHODS: 435 Enterobacterales isolates from 621 patients attending 12 urological departments in Poland were screened by PCR for PMQR genes. PMQR-positive isolates were tested for quinolone susceptibility and investigated by whole genome sequencing (WGS) methods. RESULTS: In total, 32 (7.35%) E. coli strains with ciprofloxacin MIC in the range 0.125-32 mg/L harbored at least one PMQR gene. qnrS and qnrB were the most frequent genes detected in 16 and 12 isolates, respectively. WGS was performed for 28 of 32 PMQR-producing strains. A variety of serotypes and sequence types (STs) of E. coli was noticed. All strains carried at least one virulence gene. AMR genes that encoded resistance against different classes of antibiotics were identified. Additionally, five of 13 ciprofloxacin-susceptible E. coli had alterations in codon 83 of the GyrA subunits. CONCLUSION: This study provides information on the common presence of PMQRs among E. coli, which may explain the cause for development of post-TRUS-Bx infections. High numbers of virulence and antimicrobial resistance genes detected show a potential for analysed strains to develop infections.

The molecular mechanisms of fluoroquinolone resistance found in rectal swab isolates of Enterobacterales from men undergoing a transrectal prostate biopsy: the rationale for targeted prophylaxis.

BACKGROUND: Transrectal ultrasound-guided prostate biopsy (TRUS-Bx) is considered an essential urological procedure for the histological diagnosis of prostate cancer. It is, however, considered a "contaminated" procedure which may lead to infectious complications. Recent studies suggest a significant share of fluoroquinolone-resistant rectal flora in post-biopsy infections. METHODS: The molecular mechanisms of fluoroquinolone resistance, including PMQR (plasmid-mediated quinolone resistance) as well as mutation in the QRDRs (quinolone-resistance determining regions) of gyrA, gyrB, parC and parE, among Enterobacterales isolated from 32 of 48 men undergoing a prostate biopsy between November 2015 and April 2016 were investigated. Before the TRUS-Bx procedure, all the patients received an oral antibiotic containing fluoroquinolones. RESULTS: In total, 41 Enterobacterales isolates were obtained from rectal swabs. The MIC of ciprofloxacin and the presence of common PMQR determinants were investigated in all the isolates. Nine (21.9%) isolates carried PMQR with qnrS as the only PMQR agent detected. DNA sequencing of the QRDRs in 18 Enterobacterales (E. coli n = 17 and E. cloacae n = 1) isolates with ciprofloxacin MIC ≥ 0.25 mg/l were performed. Substitutions in the following codons were found: GyrA-83 [Ser → Leu, Phe] and 87 [Asp → Asn]; GyrB codon-605 [Met → Leu], ParC codons-80 [Ser → Ile, Arg] and 84 [Glu → Gly, Met, Val, Lys], ParE codons-458 [Ser → Ala], 461 [Glu → Ala] and 512 [Ala → Thr]. Six isolates with ciprofloxacin MIC ≥ 2 mg/l had at least one mutation in GyrA together with qnrS. CONCLUSIONS: This study provides information on the common presence of PMQRs among Enterobacterales isolates with ciprofloxacin MIC ≥ 0.25 mg/l, obtained from men undergoing TRUS-Bx. This fact may partially explain why some men develop post-TRUS-Bx infections despite ciprofloxacin prophylaxis.

Antimicrobial Resistance and Whole-Genome Characterisation of High-Level Ciprofloxacin-Resistant Salmonella Enterica Serovar Kentucky ST 198 Strains Isolated from Human in Poland.

BACKGROUND: Salmonella Kentucky belongs to zoonotic serotypes that demonstrate that the high antimicrobial resistance and multidrug resistance (including fluoroquinolones) is an emerging problem. To the best of our knowledge, clinical S. Kentucky strains isolated in Poland remain undescribed. METHODS: Eighteen clinical S. Kentucky strains collected in the years 2018-2019 in Poland were investigated. All the strains were tested for susceptibility to 11 antimicrobials using the disc diffusion and E-test methods. Whole genome sequences were analysed for antimicrobial resistance genes, mutations, the presence and structure of SGI1-K (Salmonella Genomic Island and the genetic relationship of the isolates. RESULTS: Sixteen of 18 isolates (88.9%) were assigned as ST198 and were found to be high-level resistant to ampicillin (>256 mg/L) and quinolones (nalidixic acid MIC ≥ 1024 mg/L, ciprofloxacin MIC range 6-16 mg/L). All the 16 strains revealed three mutations in QRDR of GyrA and ParC. The substitutions of Ser83 → Phe and Asp87 → Tyr of the GyrA subunit and Ser80→Ile of the ParC subunit were the most common. One S. Kentucky isolate had qnrS1 in addition to the QRDR mutations. Five of the ST198 strains, grouped in cluster A, had multiple resistant determinants like blaTEM1-B, aac(6')-Iaa, sul1 or tetA, mostly in SGI1 K. Seven strains, grouped in cluster B, had shorter SGI1-K with deletions of many regions and with few resistance genes detected. CONCLUSION: The results of this study demonstrated that a significant part of S. Kentucky isolates from humans in Poland belonged to ST198 and were high-level resistant to ampicillin and quinolones.

Microbial degradation of polyhydroxybutyrate with embedded polyhexamethylene guanidine derivatives.

The aim of this study was to isolate biofilm-forming bacteria that are capable of degrading polyhydroxybutyrate (PHB) with polyhexamethylene guanidine (PHMG) derivatives. The three types of derivatives incorporated in PHB and their concentration affected the biodegradability of the tested films in both water and compost. The PHMG derivative granular polyethylene wax at the highest concentration significantly inhibited BOD in both environments. At the same time, in water, PHB with PHMG stearate at 1% concentration was also found to inhibit biodegradation but to a lesser extent than PHMG polyethylene wax granulate. Analyzing the values of biofilm abundance and their hydrolytic activity in water, low concentrations of PHMG derivatives (0.2 and 0.6%) slightly inhibited biofilm abundance on the surface of the tested composites. Only granular polyethylene wax PHMG (at 1% concentration) significantly reduced biofilm formation and hydrolase activity in the compost to the greatest extent. Bacteria from biofilm were isolated and identified. Based on the 16S rRNA gene sequence, the strains belong to Bacillus toyonensis HW1 and Variovorax boronicumulans HK3. Introduction of the tested isolates to the environment can enhance composites degradation. However, this requires further research.

Antibiotic and Disinfectant Resistance in Tap Water Strains - Insight into the Resistance of Environmental Bacteria.

Although antibiotic-resistant bacteria (ARB) have been isolated from tap water worldwide, the knowledge of their resistance patterns is still scarce. Both horizontal and vertical gene transfer has been suggested to contribute to the resistance spread among tap water bacteria. In this study, ARB were isolated from finished water collected at two independent water treatment plants (WTPs) and tap water collected at several point-of-use taps during summer and winter sampling campaigns. A total of 24 strains were identified to genus or species level and subjected to antibiotic and disinfectant susceptibility testing. The investigated tap water ARB belonged to phyla Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes. The majority of the isolates proved multidrug resistant and resistant to chemical disinfectant. Neither seasonal nor WTP-dependent variabilities in antibiotic or disinfectant resistance were found. Antibiotics most effective against the investigated isolates included imipenem, tetracyclines, erythromycin, and least effective - aztreonam, cefotaxime, amoxicillin, and ceftazidime. The most resistant strains originate from Afipia sp. and Methylobacterium sp. Comparing resistance patterns of isolated tap water ARB with literature reports concerning the same genera or species confirms intra-genus or even intra-specific variabilities of environmental bacteria. Neither species-specific nor acquired resistance can be excluded.

Microbial communities of biofilms developed in a chlorinated drinking water distribution system: A field study of antibiotic resistance and biodiversity.

Antibiotic resistance and biodiversity were investigated in microbial communities attached to inner surfaces of water supply fittings in a chlorinated drinking water distribution system (DWDS) supplied by two independent water treatment plants (WTPs) drawing the same source water. The investigation of the effect of the season, the applied water treatment technology, and type, material, and age of water supply fittings on both antibiotic resistance and biodiversity in biofilms involved collection of tubercles during summer and winter seasons throughout the DWDS. A total of 16 samples were collected (8 per season) from areas supplied by two independent WTPs. Culturable aerobic antibiotic resistant bacteria (ARB) proved more prevalent in summer. Various antibiotic resistance genes (ARGs) were detected, confirming the role of biofilms as ARGs reservoirs, but the abundances of quantified genes (sulI, ermB, qacEΔ1, intI1) were low (a range of

Seasonal variability of chemical composition and mutagenic effect of organic PM2.5 pollutants collected in the urban area of Wroclaw (Poland).

The objective of the study was the assessment of the mutagenicity of chemical pollutants adsorbed on suspended particulate matter with aerodynamic diameter < 2.5 µm (PM2.5) in the four seasons. Samples were collected from the urban agglomeration of Wroclaw, Poland and evaluated for mutagenicity using two Salmonella typhimurium strains TA98 and TA100 with and without metabolic activation with microsomal fraction S9. The work covered sampling of suspended dusts in four seasons: summer, spring, autumn and winter. The dust samples were collected on glass filters using air aspirator and the organic matter of PM2.5 was extracted using Soxhlet extractor. The levels of polycyclic aromatic hydrocarbon compounds (PAH), nitro-PAH and dinitro-PAH were determined in the extract. Variable degree of air pollution with mutagenic substances was determined at the selected study site. A greater, negative effect of chemical compounds on DNA was determined in dust samples collected in the autumn-winter season in comparison to samples collected in the spring-summer season. In the majority of tests, higher mutagenicity was obtained in analyses conducted on total extracts in comparison to tests conducted in the presence of PAH pollutant fractions. The obtained mutagenic ratio values pointed to the presence of chemical compounds with a character of both promutagens and direct mutagens. Samples collected in the autumn-winter season were observed to have a higher diversity of organic substances absorbed on PM2.5 dusts. Particular samples differed in the total content and percent contribution of particular PAHs, nitro-PAHs, and other organic compounds. In addition, the identified substances included compounds belonging to different chemical classes: aliphatic compounds, cycloalkanes, mono- and bicycling arenes, polycyclic arenes, compounds containing oxygen, nitrogen, and sulphur.

Biodiversity of organisms inhabiting the water supply network of Wroclaw. Detection of pathogenic organisms constituting a threat for drinking water recipients.

The objective of the article was to present the diversity of organisms inhabiting the water supply network with particular consideration of pathogenic organisms that can cause an epidemiological threat, with the application of high throughput sequencing (HTS). The study material was water sampled from 15 points in the water supply system. High species diversity of bacteria was evidenced, as well as the presence of microorganisms from genus Clostridium and family Enterobacteriaceae. No presence of bacteria Clostridium perfringens was recorded, which suggests proper performance of water treatment processes. Owing to advanced techniques of molecular biology, the article also presents species very similar to pathogenic bacteria the detection of which is not possible by means of standard water analysis (plate culture). Based on literature data and very high similarity of the genome of the bacteria to that of pathogenic bacteria, the species are considered to potentially show the same negative character towards the recipient, and cause a serious epidemiological threat. Therefore, the performed analyses show that classic methods of assessment of sanitary quality of water are not fully sufficient, and HTS analysis should be performed as an auxiliary tool to provide the complete image of the community in the existing network.

Mutagenicity of indoor air pollutants adsorbed on spider webs.

In this study, air pollutants were determined on spider webs collected from six indoor sites in the Lower Silesia region, southwest Poland. In order to assess the mutagenicity (M) of the collected samples, the standard Salmonella assay was used with two Salmonella typhimurium strains, TA98 and YG1041. The assays were conducted with and without metabolic activation (S9 mix). The presence of 15 polycyclic aromatic hydrocarbons (PAHs) and PAH-derivatives (nitro-PAHs; NPAHs) on spider webs was also assessed at the studied sites. The total PAH content of collected samples ranged from 1.65 to 51.75 µg g-1; the total NPAH content ranged from 0.22 to 2.44 µg g-1. The highest PAH concentration was found at two sites: a basement with coal heating (S4) and a garage (S6). Samples from these two sites were also characterized by the highest mutagenicity values in TA98 strain (65,127 and 35,565 revertants/g of web in the absence and presence of S9 mix, respectively, for S4 and 54,753 and 46,262 revertants/g, respectively, for S6). For strain YG1041, the highest values were obtained in a basement with coal heating; values were 233,748 and 185,321 revertants/g of web in the absence and presence of S9 mix, respectively. The concentration of PAHs was significantly correlated with the mutagenicity (M) of the web samples collected. Reassuming, people are exposed to substances with possible carcinogenic properties and potential adverse health effect through the ambient air due to vehicular traffic, heating systems, cooking habits etc. The application of spider webs sampling could bring the very important information regarding the possible health effect associated with indoor air, making these kind of studies cheap and reliable.

Emergence of Enterobacteriaceae co-producing CTX-M-15, ArmA and PMQR in Poland.

BACKGROUND: Plasmid-mediated extended-spectrum ß-lactamases (ESBLs), 16S rRNA methylases and quinolone resistance mechanisms (PMQRs) are well-known agents conferring resistance to more than 1 antimicrobial in its group. The accumulation of these agents poses, therefore, a serious risk to public health. OBJECTIVES: The objective of this study was to investigate the presence of common ß-lactamases and 16S rRNA methylases in Qnr-producing Enterobacteriaceae and their genetic relatedness. MATERIAL AND METHODS: We examined 18 Qnr-producing isolates (Klebsiella pneumoniae n = 8, Enterobacter cloacae n = 6 and Escherichia coli n = 4) selected from a collection of 215 ciprofloxacin-resistant strains obtained from patients in a 1030-bed tertiary hospital from 1 March to 31 August 2010. The antibiotics minimum inhibitory concentration (MIC) was determined by E-test. The detection of common ß-lactamases, 16S rRNA methyltransferases and PMQR genes was performed by polymerase chain reaction (PCR) and sequencing. Genetic relatedness was assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). RESULTS: All the isolates tested were susceptible to carbapenems and colistin, while 16 were multidrug-resistant. Thirteen, 2 and 2 isolates carried qnrB1, qnrA1 and qnrS1, respectively. Ten of 13 qnrB1-positive Enterobacteriaceae also carried genes encoding for aac(6')-Ib-cr and at least 1 ESBL. The blaCTX-M-15 gene was the most common ESBL. The most prevalent combination of genes was qnrB1+aac(6')-Ib-cr+blaTEM-1+blaCTX-M-15. Two isolates of K. pneumoniae and E. cloacae were found to bear multiple extended range resistance traits: ArmA, CTX-M-15, QnrB1, and AAC (6')-Ib-cr. The PFGE showed that most of the isolates exhibited individual DNA patterns, whilst MLST assigned K. pneumoniae (n = 8) to 5 sequence types (STs) (ST15, ST323, ST336, ST147, and ST525), E. coli (n = 4) to 2 (ST131 and ST1431) and E. cloacae (n = 5) to 4 (ST90, ST89, ST133, and the novel ST407). CONCLUSIONS: Our findings reveal the accumulation of resistance traits and their important role in spreading of multiresistant bacteria among hospitalized patients.

Draft genome sequence of an Escherichia coli ST410 isolate co-harbouring blaCTX-M-15, blaCMY-42, blaOXA-1, aac(3)-IIa and aac(6')-Ib-cr genes with gyrA and parC mutations isolated from a paediatric patient in Poland.

OBJECTIVES: Escherichia coli is one of the major causative agents of nosocomial infections. Here we report the first draft genome sequence of an E. coli strain (no. 158) isolated in Poland carrying blaCTX-M-15, blaCMY-42, blaOXA-1, aac(3)-IIa and aac(6')-Ib-cr genes together with mutations in the gyrA and parC genes. METHODS: Total DNA was sequenced using an Illumina NextSeq 500 platform. The draft genome of E. coli strain 158 was assembled using SPAdes 3.9 assembler. Contigs were annotated using the Prokka v.1.12 algorithm. Species confirmation, multilocus sequence typing (MLST), serotyping, molecular virulence and resistance traits, and plasmid replicons were analysed using appropriate bioinformatics tools available at the Centre for Genomic Epidemiology website. Additional in silico analyses were also conducted. RESULT: The genome size was estimated at 4883487bp, with 4601 predicted coding sequences. The presence of blaCTX-M-15, blaCMY-42, blaOXA-1, aac(3)-IIa and aac(6')-Ib-cr genes was detected in addition to other antimicrobial resistance genes as well as mutations in the gyrA (Ser83Leu and Asp87Asn) and parC (Ser80Ile) genes. The investigated strain E. coli 158 belongs to ST410. CONCLUSION: To our knowledge, this is the first draft genome of an E. coli strain co-harbouring blaCTX-M-15, blaCMY-42, blaOXA-1, aac(3)-IIa and aac(6')-Ib-cr genes with mutations in gyrA and parC reported in Poland. The reported genome sequence contains valuable information on genetic features of antimicrobial resistance mechanisms of E. coli in Poland.

Pertactin-deficient Bordetella pertussis isolates in Poland-a country with whole-cell pertussis primary vaccination.

The introduction of pertussis vaccination in the 1950s resulted in a significant decrease in the incidence of disease. However, since the 1990s many highly vaccinated countries have observed the re-emergence of the disease. One of the causes of this phenomenon might be related to the adaptation of Bordetella pertussis to vaccination. The purpose of the presented study was an investigation of the emergence and spread of vaccine antigen-deficient B. pertussis isolates in Poland and genomic characterization of the currently circulating pathogen population using PFGE, MLVA and MAST. The results revealed that all tested isolates expressed Ptx, FHA and ACT antigens but 15.4% (4/26) of isolates from 2010 to 2016 were Prn-deficient. Moreover, one TcfA-deficient isolate was collected in 2015. The genotyping showed a genetic distinction between the isolates circulating in 2010-2016 and isolates from previous periods. The majority of currently circulating isolates belonged to PFGE group IV (96.2%), type MT27 (73.1%), and carried ptxA1-ptxC2-ptxP3-prn2-tcfA2-fim2-1-fim3-1 alleles (61.5%). The unique genetic structure of the B. pertussis population in Poland has changed since 2010 and became similar to that observed in countries with aP vaccination. This could be a result of increasing use of aP vaccines (60% of primary vaccination in 2013) over wP vaccines, which have been broadly used for primary vaccination in Poland for decades.

Application of semipermeable membrane devices for long-term monitoring of polycyclic aromatic hydrocarbons at various stages of drinking water treatment.

The primary goal of the presented study was the investigation of occurrence and concentration of sixteen selected polycyclic aromatic hydrocarbons in samples from various stages of water treatment and verification of the applicability of semi-permeable membrane devices in the monitoring of drinking water. Another objective was to verify if weather seasons affect the concentration and complexity of PAHs. For these purposes, semipermeable membrane devices were installed in a surface water treatment plant located in Lower Silesia (Poland). Samples were collected monthly over a period of one year. To determine the effect of water treatment on PAH concentrations, four sampling sites were selected: raw water input, a stream of water in the pipe just before ozonation, treated water output and water after passing through the distribution system. After each month of sampling, SPMDs were exchanged for fresh ones and prepared for instrumental analysis. Concentrations of polycyclic aromatic hydrocarbons were determined by high-performance liquid chromatography (HPLC). The presented study indicates that semipermeable membrane devices can be an effective tool for the analysis of drinking water, in which organic micropollutants occur at very low concentrations.

Distribution of 16S rRNA Methylases Among Different Species of Aminoglycoside-Resistant Enterobacteriaceae in a Tertiary Care Hospital in Poland.

BACKGROUND: Aminoglycosides are a group of antimicrobial agents still the most commonly used in the treatment of life-threatening bacterial infections in human and animals. The emergence and spread of 16S rRNA methylases, which confer high-level resistance to the majority of clinically relevant aminoglycosides, constitute a major public health concern. OBJECTIVES: Our goal was to evaluate the distribution of 16S rRNA methylases among different species of Enterobacteriaceae during a five month-long survey in a tertiary hospital in Warszawa, Poland. MATERIAL AND METHODS: In the survey, a total of 1770 non-duplicate clinical isolates were collected from all hospital wards in a tertiary hospital in Warszawa, Poland. The survey was conducted between 19 April and 19 September 2010. The ability to produce 16S rRNA methylase was examined by determining MICs for gentamicin, kanamycin, amikacin by means of the agar dilution method. The isolates resistant to high concentration of aminoglycosides were PCR tested for genes: armA, rmtA, rmtB and rmtC. PCR products were subjected to DNA sequencing by the Sanger method. The genetic similarity of the ArmA-producing isolates was analysed by pulsed-filed gel electrophoresis (PFGE). RESULTS: ArmA was the only 16S rRNA methylase detected in 20 of 1770 tested isolates. The overall prevalence rate of ArmA was 1.13%. In K. pneumoniae (n = 742), P. mirabilis (n = 130), and E. cloacae (n = 253) collected in the survey, the prevalence of ArmA was 0.4%, 0.8% and 5.9%, respectively. The PFGE revealed both horizontal and clonal spread of the armA gene in the hospital. CONCLUSIONS: The prevalence of 16S rRNA methylase ArmA reported in this study is significantly higher than observed in other countries in Europe.

[Advantages and disadvantages of microbiological methods used in the diagnosis of Mycoplasmapneumoniae infections in selected clinical situation]. / Wady i zalety mikrobiologicznych metod diagnostycznych stosowanych w rozpoznaniu zakazenia wywolanego przez Mycoplasma pneumoniae na przykladzie wybranej sytuacji klinicznej.

Mycoplasma pneumoniae is one of the most common causes of community-acquired pneumonia in children and adults. Correct and rapid laboratory diagnosis of M pneumoniae infections is important to introduce appropriate antibiotic treatment. Diagnosis for M. pneumoniae usually relies on serological tests and/or molecular investigations. Both methods have some advantages but also limitations. This paper presents advantages and disadvantages of microbiological methods used in M. pneumoniae infection an example of case of patient with mycoplasmosis.