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.

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.

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.

Probable Interspecies Transfer of the bla(VIM-4) Gene between Enterobacter cloacae and Klebsiella pneumoniae in a Single Infant Patient.

We report the interspecies transfer of the bla(VLM-4) gene in MBL-producing Enterobacter cloacae and Klebsiella pneumoniae isolates from a newborn patient who had received meropenem therapy. We show evidence that gene bla(VIM-4) was transmitted as a part of the class-1 integron on a ca. -90 kb conjugative plasmid. High homology of nucleotide sequence was observed between the integron found in VIM-4 producing E. cloacae and K. pneumoniae strains tested and class-1 integrons previously reporteded in Pseudomonas aeruginosa from Hungary and Poland. This finding may suggest P. aeruginosa as a potential source of acquired VIM-4 in Enterobacteriaceae.

[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.

Usefulness of laboratory methods in diagnosis of pertussis in adult with paroxysmal cough.

INTRODUCTION: Pertussis is an acute, highly contagious bacterial infection of respiratory system caused by Bordetella pertussis. Principally, disease affects young children, however, recently it is also reported in adolescents and adults. Symptoms of pertussis in adults are non-specific, i.e. dry, paroxysmal and protracted cough. Thus, it is rarely diagnosed in this group. AIM: This paper aimed at evaluating the usefulness of the laboratory methods in diagnosis of pertussis in adults based on a case presenting with dry, paroxysmal and chronic cough. MATERIAL AND METHODS: Sputum (collected on 25th January 2013) and paired serum samples (collected on 13th February and 19 April 2013) were tested. Pertussis diagnostics involved culture, in-house PCR, real-time PCR and ELISA. RESULTS: Sputum culture, using commercial medium Bordetella Selective Medium by Oxoid did not reveal the presence of B. pertussis. Real-time PCR and PCR, however, confirmed the presence of insertion sequence IS481 and pertussis toxin promoter sequence ptx-Pr, markers indicative of B. pertussis infection. Serological testing revealed the high titres of IgA, IgG and IgM antibodies to B. pertussis in the first sample. In the second sample, collected 2 months following the first one, a significant decrease in IgA antibodies was reported. CONCLUSIONS: These data suggest a high usefulness of the laboratory methods in the diagnosis of pertussis in adults with chronic cough. Application of such methods ensures adequate diagnosis of disease, quick introduction of proper treatment and implementation of procedures preventing the spread of infection.

[Detection of bordetella within the framework of the Eupert-labnet Bordetella PCR EQA]. / Wykrywanie paleczek Bordetella w ramach miedzynarodowego sprawdzianu Eupert-labnet Bordetella PCR EQA.

INTRODUCTION: The aim of this study was evaluation of molecular identification results of samples including genomic DNA of Bordetella by using PCR method, obtained by laboratory of Department of Bacteriology NIZP-PZH and their comparison with the results obtained by other reference laboratories in EU. The study was conducted within the framework of the first external quality assessment (Eupert-labnet Bordetella PCR EQA). METHODS: The panel of ten coded samples of purified genomic DNA was investigated. The panel was designed to include dilution of genomic DNA from B. pertussis at the three concentrations 2 pg/microl (high), 0,2 pg/microl (medium) and 0,02 pg/microl (low). The panel included as well DNA of other Bordetella species (B. parapertussis, B. holmesii, B. bronchiseptica) and H. influenzae at concentrations 2 pg/microl. There was also two ,,blank" samples containing only Tris Buffet (10mM, pH 8,0). Presence or absence of B. pertussis DNA in the tested samples was determined by using four PCR assays: conventional in-house PCR (detection of IS481 B. pertussis and IS1001 B. parapertussis), commercial multiplex PCR (detection of DNA B. pertussis), conventional in-hause real-time PCR (detection of IS481 B. pertussis) and commercial real-time PCR (detection of IS1001 B. parapertussis). RESULTS: All but one samples were correctly identified in our laboratory. Laboratory of Department of Bacteriology NIZP-PZH correctly detected DNA ofB. pertussis at both the ,,high" and ,,medium" dilution. In addition, the distinction between B. pertussis and other Bordetella species was correctly obtained by our laboratory. The negative samples, the two blank samples and one containing H. influenzae were correctly detected. CONCLUSIONS: Results of the first international external quality assessment have confirmed competences of laboratory of Department of Bacteriology NIZP-PZH in molecular identification of Bordetella pertussis.

[Sequence-based typing--molecular typing of Legionella pneumophila strains within the framework of an international external quality assessment]. / Sequence-based typing--molekularne typowanie szczepów Legionella pneumophila w ramach miedzynarodowego sprawdzianu external quality assessment.

INTRODUCTION: The aim of the study was evaluation results of molecular typing L. pneumophila strains that was carried by using SBT (Sequence-Based Typing) method, obtained by laboratory of Department of Bacteriology NIZP-PZH within the framework of the ninth international external quality assessment (ELDSNet Legionella pneumophila DNA SBT) and their comparision with the results obtained by other reference laboratories in EU. MATERIAL AND METHODS: The panel of five coded isolates of L. pneumophila was investigated. Genomic DNA of Legionella were extracted and defined regions of seven genes were amplified by PCR and sequenced. Then, consensus sequence of the correct length were generated. In order to determine the complete allelic profile and Seqence Type (ST) forward and reverse sequence for each allele were submitted online by using the L. pneumophila database. RESULTS: All of L. pneumoniae isolates sent to genotyping by SBT method were correctly identified in our laboratory. CONCLUSIONS: Results of the ninth international external quality assessment have confirmed competences of laboratory of Department of Bacteriology NIZP-PZH in typing of L. pneumophila isolates accordance with the requirements of the international classification.

[Occurrence and characterisation of aac(6')-Ib-cr gene encoding fluoroquinolone-modifying enzyme in clinical ciprofloxacin-resistant Enterobacteriaceae strains isolated in Poland]. / Wystepowanie i charakterystyka genu aac(6')-Ib-cr kodujacego enzym modyfikujacy fluorochinolony u opornych na ciprofloksacyne szczepów Enterobacteriaceae wyizolowanych od ludzi.

INTRODUCTION: The aac(6')-Ib-cr gene encodes a variant of aminoglycoside acetyltransferase that confers reduced susceptibility to hydrophilic fluoroquinolones such as ciprofloxacin and norfloxacin. AAC(6')-Ib-cr has two amino acid changes, Trp 102Arg and Asp179Tyr, which together are necessery and sufficient for the enzyme's ability to reduce the activity of fluoroquinolones, including ciprofloxacin and norfloxacin. The aim of this study was to evaluate the prevelance of aac(6')-Ib-cr determinant among 15 Enterobacteriaceae isolates randomly chosen from 215 fluorochinolone resistant strains recovered during the 6 months of 2010. METHODS: The aac(6')-Ib was detected by PCR. The presence of aac(6')-Ib-cr gene variant was futher identified by digestion with BseGI (BtsCI) and sequencing. RESULTS: 11/15 of the resistant (MIC CIP 2-1024 microg/ml) Enterobacteriaceae strains carried aac(6')-Ib-cr variant. CONCLUSION: This is the first study identifying the variant of aminoglycoside acetyltransferase determinant in Poland. Our results demonstrate that this enzym may be even more widespread than Qnr determinants among fluoroquinolone resistant Enterobacteriaceae in Poland.

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.

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.

[Characteristic of fluoroquinolone resistant clinical isolates of K. pneumoniae, P. mirabilis and E. coli producing ESBL and AmpC beta-lactamases]. / Charakterystyka opornych na fluorochinolony izolatów z gatunku K. pneumoniae, P. mirabilis i E. coli wytwarzajacych beta - laktamazy typu ESBL i AmpC.

INTRODUCTION: Extended-spectrum beta-lactamases (ESBLs) are the predominant mechanism for acquired antibiotic resistance in Enterobacteriaceae. During the past few years, increasing occurrence of plasmid-mediated AmpC beta-lactamases (pAmpCs) particularly in K. pneumonia, P. mirabilis and E. coli was reported. Therefore, the aim of our study was to analyse of the diversity of plasmid-mediated beta-lactamases such as pAmpCs and ESBLs among clinical K. pneumonia, P. mirabilis and E. coli strains in Poland. METHODS: A total of 19 clinical Enterobacteriaceae strains (E. coli, n = 9; K. pneumoniae, n = 7; P. mirabilis, n = 3) resistant to third-generation cephalosporin were selected from collection of fluoroquinolone resistant isolates recovered during a 6-months period in regular hospital in Warsaw, Poland. ESBLs and AmpCs were detected by using phenotypic methods: double-disc tests (DDSTs), MAST ID D68C test, sensitivity to cefoxitin, disk potentiation test (DPT) and Tris-EDTA test. Polymerase chain reaction (PCR) amplification of the bla(AmpC), bla(CTM-M), bla(TEM), and bla(SHV), genes. PCR-products for these genes were sequenced. To determine the possible clonality of the tested isolates PFGE with the XbaI was performed. RESULTS: Nine of 19 fluoroquinolone-resistant strains tested produced extended-spectrum beta-lactamases of TEM, SHV and CTX-M families. These ESBLs were most commonly detected in E. coli. AmpC beta-lactamases were produced by 6 tested strains, including 3 isolates of P. mirabilis. The AmpC found in our study belonged to CMY and DHA families, Furthermore, 4 isolates of K. pneumoniae were found to co-produce both ESBL and AmpC beta-lactamases. XbaI-PFGE profiles pointed significant differences of tested strains. CONCLUSION: Horizontal transfer of genes encoding for acquired beta-lactamases such ESBL and AmpC seem to play primary role in dissemination of these resistance traits among fluoroquinolone-resistant clinical strains of Enterobacteriaceae in Poland.

[Prevalence of qnr genes in clinical Enterobacteriaceae non-susceptible to fluoroquinolone in Poland]. / Wystepowanie genów qnr u niewrazliwych na fluorochinolony paleczek z rodziny Enterobacteriaceae izolowanych z materialu klinicznego.

INTRODUCTION: Fluoroquinolone are broad-spectrum antimicrobial agents extensively used by physicians. This widespread use has been associated with increased level ofquinolone resistance strains, particularly in Enterobacteriaceae. Plasmid-mediated quinolone resistance (PMQR) including Qnr determinants with the potential for horizontal transfer confer to quinolone resistance. Plasmid harboring qnr genes may also encode extended-spectrum beta-lactamases (ESBLs) such as CTX-M, SHV and TEM type. The prevalence ofplasmid-mediated quinolone resistance (PMQR) determinants like qnrA, qnrB and qnrS was investigated in a collection of 215 Enterobacteriaceae strains with reduced susceptibility to fluoroquinolone. METHODS: The isolates (n=215) were collected from 1 March to 31 September, 2010 in a regular hospital in Warsaw, Poland. The resistance to nalidixic acid, norfloxacin and ciprofloxacin was determinated by twofold agar dilution method, while MICs of moxifloxacin were examined by using E-test. The prevalence of qnrA, qnrB, qnrS, blaCTX-M, blaSHV and blaiTEM was evaluated by PCR. All PCR-products for qnr were sequenced. The epidemiological relationship between positive isolates was studied by PFGE method. RESULTS: Eighteen isolates (8,3%) carried the qnr gene encoding the QnrA, QnrB or QnrS. The coexistence of both qnrA and qnrS genes was noted in one isolate of E. coli. The qnrB gene was the most common qnr type found. All the Qnr-producing strains were simultaneously resistant to naldixic acid and different - level non-susceptible fluoroquinolone (MIC CIP 1.5-1024 microg/ml). Most of qnr-positive strains (88.9%) were extended-spectrum beta-lactamase (ESBL) producers of CTX-M and TEM types predominantly. CONCLUSIONS: The present study highlights the wide spread of Qnr-like determinants in clinical Enterobacteriaceae non-susceptible to fluoroquinolone in Poland, with an association with the ESBL.

Emergence of Klebsiella pneumoniae coproducing KPC-2 and 16S rRNA methylase ArmA in Poland.

A Klebsiella pneumoniae epidemic strain that coproduced carbapenemase KPC-2 (K. pneumoniae carbapenemase 2) and 16S rRNA methylase ArmA has emerged in Poland. Four nonduplicate isolates from patients in a hospital in Warsaw, Poland, were found to carry the bla(KPC-2) and armA genes on ca. 50-kb and 90-kb plasmids, respectively. Tn4401 with a 100-bp deletion in the variable region was detected in all the isolates. XbaI pulsed-field gel electrophoresis (PFGE) revealed 93.2% similarity of the isolates. All the isolates were resistant to carbapenems and 4,6-disubstituted 2-deoxystreptamines.

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

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.

Mutagenicity of airborne particulates assessed by salmonella assay and the SOS chromotest in Wroclaw, Poland.

Ambient air particulate matter less than 2.5 microm in aerodynamic diameter (PM(2.5)) samples were collected during summer and autumn using a Staplex high-volume air sampler. They were later extracted with dichloromethane in a Soxhlet apparatus. Polyaromatic hydrocarbon (PAH) content in extracts was determined by the high-performance liquid chromatography technique using fluorescence detection, whereas the nitro-PAH content was determined by gas chromatography using mass detection. Four Salmonella typhimurium strains (TA98, TA100, YG1041, and YG1042) were used in assays conducted with and without metabolic activation. The extracts were also tested with the SOS chromotest supplied by Environmental Biodetection Products Incorporated. The obtained results confirmed the Salmonella assay and the SOS chromotest usability for the purpose of atmospheric pollution monitoring within an urban agglomeration. The atmospheric pollution extracts under examination differed among each other regarding total content and percentage of individual compounds, depending on the season of sampling. The highest total PAH content and the highest nitro-PAH content in the tested samples as well as the most extensive range of detected compounds were found in the autumn season (heating season). The highest mutagenicity was noted for PM(2.5) samples collected in autumn. The high values of mutagenicity ratios and induction factors were obtained from assays carried out with and without metabolic activation, which is an argument for the presence of promutagens and direct mutagens. The YG1041 strain proved to be the most effective in detection of mutagenicity of the suspended dust extracts because of its notably high sensitivity to nitro-aromatic compounds. The SOS chromotest was very sensitive to a large spectrum of genotoxic air pollutants and showed a high degree of similarity with the results of the Salmonella assay. In comparison with the frequently used Ames test, the SOS chromotest enables quick analysis of the genotoxic effects of samples using only one tester strain. In addition, its miniaturized design decreases the consumption of tested samples.