Mechanism of Anti-Salmonella Rabbit Immunoglobulin Adsorption on Polymer Particles.

The adsorption of anti-Salmonella rabbit immunoglobulin (IgaR) on negatively charged polymer particles leading to the formation of immunolatex was studied using various techniques comprising atomic force microscopy (AFM) and laser Doppler velocimetry (LDV). Initially, the basic physicochemical properties of IgaR molecules and the particles, inter alia their electrophoretic mobilities, the zeta potentials and hydrodynamic diameters, were determined under different ionic strengths and pHs. Applying AFM, single immunoglobulin molecules adsorbed on mica were also imaged, which allowed to determine their size. The adsorption of the IgaR molecules on the particles leading to changes in their electrophoretic mobility was monitored in situ using the LDV method. The obtained results were interpreted applying a general electrokinetic model which yielded quantitative information about the molecule coverage on the particles. The obtained immunolatex was thoroughly characterized with respect to its acid-base properties and its stability upon storage. Notably, the developed procedure demonstrated better efficiency compared to commercially applied methods, characterized by a higher immunoglobulin consumption.

Kinetics of Immunolatex Deposition at Abiotic Surfaces under Flow Conditions: Towards Quantitative Agglutination Assays.

Physicochemical properties of immunolatex, prepared by incubation of negatively charged polystyrene microparticles with polyclonal rabbit IgGs, were determined by a variety of experimental techniques. These comprised dynamic light scattering (DLS), laser Doppler velocimetry (LDV) and atomic force microscopy (AFM). The particle diffusion coefficient, the hydrodynamic diameter, the electrophoretic mobility, the zeta potential and the suspension stability were determined as a function of pH for different ionic strengths. The deposition of the immunolatex on bare and polyallylamine (PAH) functionalized mica was investigated using the microfluidic oblique impinging-jet cell, with an in situ, real-time image analysis module. The particle deposition kinetics was acquired by a direct particle enumeration procedure. The measurements enabled us to determine the range of pH where the specific deposition of the immunolatex on these substrates was absent. We argue that the obtained results have practical significance for conducting efficient flow immunoassays governed by specific antigen/antibody interactions.

Results of Salmonella enterica subsp. enterica serotype identification by Salmonella Check&Trace microarray in international External Quality Assurance Systems.

INTRODUCTION: Traditionally Salmonella enterica subsp. enterica serotypes are identified by slide agglutination with specific antisera for somatic, flagellar and sometimes capsular antigens. An alternative way is genoserotyping using for example a microarray, eg. commercially available test Check&Trace Salmonella. The goal of this study was to evaluate the Check&Trace Salmonella microarray for Salmonella enterica subsp. enterica serotype identification, using Salmonella strains provided by reference laboratories during External Quality Assurance Systems organized for national reference laboratories by ECDC and WHO GFN. MATERIAL AND METHODS: 80 Salmonella enterica subsp. enterica have been tested using Check & Trace Salmonella (Check-Points BC, Netherlands). Also classical slide agglutination was performed according to EN ISO 6579:2003/Al:2007 norm, used as reference method. RESULTS: In the group of 80 tested strains, 66% were identified correctly, 4% gave uncertain results and 29% showed "Salmonella, genovar" without a serotype, of which 69% were not included in the CTS list of serotypes. Finally one strain has been recognized incorrectly. DISCUSSION: Because of IVD certification lack, the CTS test could not be recommended to clinical laboratories. AOAC-RI and OIE certification for test cause, that CTS could be used in most food, environmental and veterinary laboratories with the condition, that all unrecognized strains should be sent to a reference laboratory, to type according to EN ISO 6579:2003/Al:2007 norm, by KWM serotyping or other equal alternative methods.

Molecular Methods for Identification of Monophasic Salmonella Typhimurium Strains.

Two molecular biology methods were used to differentiate Salmonella enterica 1,4,[5],12:i:- strains: "Salmonella Check&Trace microarray" (CT) and multiplex PCR (mPCR). For 92 strains in CT result "Salmonella 1,4,[5],12:i:-" were obtained. Those strains were confirmed in mPCR as monophasic fljB-lack Salmonella Typhimurium. For 17 strains, which in CT assay were recognized as Salmonella Typhimurium, the same identification was obtained in mPCR. Reference Salmonella strains: Lagos, Agama, Tsevie, Glocester and Tumodi in CT were recognized as Salmonella genovar, in mPCR--as Salmonella O:4, H:i other than Salmonella Typhimurium, the same like Salmonella Farsta, recognized incorrectly in CT as Salmonella Typhimurium.

Usefulness of the (GTG)4-PCR for typing of monophasic Salmonella enterica isolates with antigenic shame l,4,[5],12:i:-.

INTRODUCTION: Monophasic Salmonella enterica strains presenting the antigenic shame 1,4,[5],12:i:- are becoming more prevalent. Accurate identification of such strains is hard with routine using biochemical and serological tests. Such strains can be identified with molecular tests. In this study we have tested the usefulness of(GTG)4-PCR for the diagnostic of such monophasic strains. This usefulness of this method was previously confirmed for genoserotyping of S. Enterica, Typhimurium, Infantis, Virchow, Hadar, Newport and Anatum. MATERIALS AND METHODS: 76 strains with antigenic shame l,4,[5],12:i:-, isolated in Poland in years 2007-12 were tested. Additionally (GTG)4-PCR patterns were obtained for reference strains of serotypes S. Lagos, S. Agama, S. Farsta, S. Tsevie, S. Glocester and S. Tumodi. (GTG)4-PCR was performed with DreamTaq DNA polymerase. Obtained patterns were analysed with BioNumerics software. RESULTS: No pattern specific for monophasic pattern was identified. Additionally it was also impossible to differentiate patterns obtained for S. Typhimurium, S. Farsta, S. Tsevie and S. Glocester. Only reference strains of serotypes S. Tumodi, Farsta and Agama has the distinguishable patterns of (GTG)4-PCR. CONCLUSIONS: Analysed (GTG)4-PCR method do not show the ability to distinguish S. enterica serotypes from group 04, H:i, including monophasic strains with the antigenic shame 1,4,[5],12:i:-.

Diagnostic Value of Serological Tests Against Verotoxigenic Escherichia coli in Hemolytic Uremic Syndrome in Children.

BACKGROUND: Diarrhea-associated hemolytic uremic syndrome (HUS D+) caused by verotoxigenic E. coli strains (VTEC) is a major cause of acute kidney injury in children between 1 and 5 years of age. Because of the short presence of VTEC in the gastrointestinal tract as well as difficulties with the detection of the verotoxigenic strain, identification of HUS etiology might be challenging. OBJECTIVES: The aim of the study was to assess the clinical and diagnostic value of serological tests for specific antibodies against verotoxigenic strains of E. coli in patients with HUS. MATERIAL AND METHODS: Eight children aged 8 months - 7.1 years (mean 40 ± 29 months) with symptoms of acute kidney injury, hemolytic anemia and thrombocytopenia observed after hemorrhagic diarrhea were included to the study. VTEC presence was detected in a stool culture with subsequent analysis of the ability to produce verotoxin and the presence of VT1 and VT2 as well as intimin and enterohemolysin genes. In addition, the presence of specific IgA, IgM and IgG antibodies against E. coli serogroups O26, O103, O104, O111, O121, O145 and O157 was measured using ELISA. RESULTS: In 3 subjects, VTEC O26, O157 and O104 serogroups were cultured in the stool and the specific IgA, IgM and IgG antibodies were detected. In 4 subjects, no VTEC strains were cultured, however, high titers of IgA, IgM and IgG antibodies against E. coli O26, O157 and O111 were detected. In a single patient, the negative results of bacteriological and serological analyses excluded VTEC etiology of HUS. CONCLUSIONS: A serological analysis of VTEC can confirm the result of stool culture for verotoxigenic E. coli strains and help to find the cause of HUS in case of negative results of a stool culture.

[Occurrence and characterization of monophasic Salmonella enterica subsp. enterica with antigenic formula 1,4, [5], 12: i:-isolated in Poland in 2007-2012]. / Wystepowanie i charakterystyka jednofazowych paleczek Salmonella enterica subsp. enterica o wzorze antygenowym 1,4,[5],12:i:-izolowanych w Polsce w latach 2007-20121.

INTRODUCTION: Salmonella is significant etiological agent of bacterial intestinal infections in Poland and other European Union countries. Since the 90's increasing incidence of monophasic Salmonella antigenic formula 1,4,[5],12:i:-has been observed, which are divided into two lineages: Spanish and European. More common European lineage are characterized by antimicrobial resistance ASSuT and DT193 phagetype. In many European countries, these organisms have become one of the most commonly isolated serovars. The aim of this study was to analyze strains of Salmonella enterica subsp. enterica strains with antigenic formula 1,4,[5],12: i:-, isolated in Poland in 2007-2012 years. MATERIAL AND METHODS: The material for the study was 146 Salmonella strains initially identified as Salmonella antigenic formula 1,4,[5],12:i,-, isolated in 2007-2012 from clinical, food and animal samples. All strains has been reidentified according to the methodology routinely used in the laboratory. Serovar has been identified using classical method--slide agglutination for somatic and flagellar antigens and using Check&Trace Salmonella microarray. The fljB gene,fliB-fliA intergenic region, selected Salmonella Pathogenicity Islands' (SPIs) genes and spvC has been detected using PCR. For all strains PFGE typing with HindIII enzyme has been performed and phagetyping also. Moreover antimicrobial resistance has been evaluated by establishing of MIC according EUCAST recommendation. RESULTS: 110 (75%) strains were S. enterica 1,4,[5],12:i,-. In this group for 17 strains in Check&Trace Salmonella microarray result of identification "Salmonella Typhimurium" have been obtained. All 110 strains have 1000 bp size DNA fragment with IS200 sequence, characteristic for S. Typhimurium. Only in case of 4 strains fljB gene has been detected. All strains harbor avrA, ssaQ, mgtC and siiD genes. For 6 strains spvC gene has been not detected. 92 strains (83.6%) have been typed as DT193, but in case of 40 strains additional reaction with phage no 18 has been observed. For 104 (94.5%) strains resistance for at least one antimicrobial have been detected. Most frequent (44 strains - 40%) resistance pattern was ASSuT. Among all strains 11 pulsotypes, which group two or more strains have been recognized, which contain 37 strains. The rest of strains have unique REA-PFGE patterns. CONCLUSIONS: To this time epidemiological situation of S. enterisa 1,4,[5],12:i:- isolated from human cases in Poland has been not recognized. Results of current studies show, that studied strains belong to european non-spanish lineage of monophasic S. Typhimurium and problem of infection caused by those strains is unrecognized and probably increase.

TRS-based PCR as a potential tool for inter-serovar discrimination of Salmonella Enteritidis, S. Typhimurium, S. Infantis, S. Virchow, S. Hadar, S. Newport and S. Anatum.

Salmonella enterica subsp. enterica comprises a number of serovars, many of which pose an epidemiological threat to humans and are a worldwide cause of morbidity and mortality. Most reported food infection outbreaks involve the serovars Salmonella Enteritidis and Salmonella Typhimurium. Rapid identification to determine the primary sources of the bacterial contamination is important to the improvement of public health. In recent years, many DNA-based techniques have been applied to genotype Salmonella. Herein, we report the use of a manual TRS-PCR approach for the differentiation of the Salmonella enterica subspecies enterica serovars in a single-tube assay. One hundred seventy Salmonella strains were examined in this work. These consisted of serovars S. Enteritidis, S. Typhimurium, S. Infantis, S. Virchow, S. Hadar, S. Newport and S. Anatum. Five of the TRS-primers, N6(GTG)4, N6(CAC)4, N6(CGG)4, N6(CCG)4 and N6(CTG)4, perfectly distinguished the S. Enteritidis and S. Typhimurium serovars, and the N6(GTG)4 primer additionally grouped the other five frequently isolated serovars. In our opinion, the TRS-PCR methodology could be recommended for a quick and simple DNA-based test for inter-serovar discrimination of Salmonella strains.

[Gut microbiome and its dysbiosis as an important factor influencing the human health condition]. / Mikrobiom przewodu pokarmowego i jego dysbiozy jako istotny czynnik wplywajacy na kondycje zdrowotna organizmu czlowieka.

Human organism consists of not only from numerous of eukaryotic cells but also from thousands of microorganisms. The most complicated is the microflora of gastrointestinal tract. Numerous studies indicates that the complex network of interactions between the host organism and its microbiome can have a very significant impact on the health condition of the host. These interactions can affect not only to gastrointestinal tract but can be related to different processes and organs. Disturbance of the homeostasis, e.g. after antibiotic course, can therefore have significant health implications Therefore, very important is the deepest exploring of the network of these interactions and dependencies.

Impact of antibiotics on the intestinal microbiota and on the treatment of Shiga-toxin-producing Escherichia coli and Salmonella infections.

This review evaluates the current literature based on the impact of antibiotics on the intestinal microbiota and the critical role of intestinal bacteria in controlling infection and subsequent clinical disease caused by STEC and Salmonella, and the transmissibility of these important pathogens.A number of studies have indicated that antibiotic therapy could result in unexpected changes in the clinical picture of disease. This is observed, for example, in the case of infections associated with Shiga-toxin-producing Escherichia coli (STEC), when antibiotics used in treatment of the disease may increase the risk of hemolytic uremic syndrome (HUS) and thus fatal outcomes. In the case of such infections, treatment with antibiotics is usually discouraged. The use of antibiotics could cause also undesirable changes in the intestinal microbial flora and prolonged pathogen shedding, which is observed in the case of Salmonella infections. Inappropriate antibiotic therapy can result in Salmonella remaining in the host's cells (intracellular) and thus resulting in further asymptomatic carriage and a further complication is the development of resistance.

[Rapid identification of Yersinia enterocolitica by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)]. / Identyfikacja paleczek Yersinia enterocolitica z wykorzystaniem spektroskopii mas typu MALDI-TOF.

INTRODUCTION: Yersinia enterocolitica includes both human pathogenic and non-pathogenic strains. The pathogenic strains belong to two evolutionary lineages: European and American, of mild- and high- pthogenicity, respectively. Y. enterocolitica European bioserotypes 4/O3 and 2/O9 are one of the major etiological agents of human yersiniosis worldwide. American lineage Y. enterocolitica bioserotype 1B/O8 has recently emerged in Europe. Since 2004 this high-pathogenicity bioserotype is increasingly isolated from humans in Poland. The rapid and accurate identification of pathogenic Y. enterocolitica strains is essential for diagnostic purposes. The aim of this study was to assess the usefulness of commercially available MALDI-TOF mass spectroscopy for Y. enterocolitica identification and subtyping. METHODS: A total of 33 strains of Y. enterocolitica belonging to bioserotype: 1B/O8 (n=2), 4/O3 (n=25) and 2/O9 (n=6) isolated from clinical specimens in Poland and 10 reference Y. enterocolitica 1B/O8 strains (Institute Pasteur, France) were used in this study. The identification of the Y. enterocolitica strains by MALDI-TOF MS was performed on MALDI Biotyper system (Bruker Daltonics, USA) with flexControl 3.0 software (Bruker Daltonics) according with the manufacturer's instruction. RESULTS: All of the tested Y. enterocolitica strains were correctly identified at the species level. However, American and European strains were not differentiated. CONCLUSIONS: Our data indicate that MALDI-TOF MS can be used as a first-line method for rapid identification of Y. enterocolitica strains at the species level in clinical microbiology laboratories.

[Do enteroaggregative Escherichia coli is a significant clinical problem in Poland?]. / Czy Enteroagregacyjne Escherichia coli stanowia istotny problem kliniczny w polsce?

INTRODUCTION: Enteroaggregative Escherichia coli are poorly discovered pathogenic subgroup of these microorganism. They can cause watery diarrhea witch is often persistent. It seems that infections due to EAEC could comprise significant epidemiologic problem, covered especially children from developing countries and travelers visiting these countries. METHODS: To find out, whether EAEC could comprise a problem in Poland, we examine 382 E. coli strains isolated from stool samples from patients with diarrhea in Poland in years 1997-2011. Three genes (aggR, aap and aat) were marked by Multiplex-PCR method. RESULTS: Six of examined strains (1.5%) were marked as EAEC and they were isolated equally from children and adults. CONCLUSIONS: It seems that EAEC could not comprise a significant problem in Poland but it should be taken in to account as a potential etiologic factor of diarrhea.

Validation of direct plating of a stool sample as a method for Listeria monocytogenes detection.

The aim of current studies was to validate the direct plating of a stool sample for Listeria monocytogenes detection, using selective medium Palcam agar with Palcam selective supplement. Validation was performed using stool samples collected from healthy humans inoculated with Listeria sp. strains. Stool samples were frozen to determine the influence of freezing on method robustness. The presented research defines the Listeria monocytogenes limit of detection (LOD) as 10(3) cfu/g of stools for fresh and frozen samples. Repeatability and reproducibility of the method has been confirmed using statistical methods. We show the effectiveness of direct plating of stool samples on Palcam agar with Palcam selective supplement collected for Listeria monocytogenes detection. This method could be useful for this pathogen detection in stool samples collected from patients with diarrhoea.

Molecular epidemiology of a household outbreak of Shiga-toxin-producing Escherichia coli in Poland due to secondary transmission of STEC O104:H4 from Germany.

We characterized two STEC O104 : H4 clinical isolates collected in Poland from a 7-year-old boy with haemolytic uraemic syndrome (HUS) and his nanny. This household outbreak began on 29 May 2011. Because of its time-frame, the outbreak was assumed to be part of the international STEC O104 : H4 outbreak that arose in Germany in May 2011. The two Polish isolates were Shiga-toxin-producing Escherichia coli (stx2 lpf) with enteroaggregative E. coli pathotype (aggR aap aggA), thereby sharing the unique virulence properties of the epidemic STEC O104 : H4 strain from the international outbreak. The Polish isolates were multi-drug resistant and carried bla(TEM), strA, strB, tetA, sul1 and sul2 markers together with the bla(CTX-M-15) gene for CTX-M-15 extended-spectrum ß-lactamase. PFGE patterns and plasmid profiles of the Polish isolates and the epidemic STEC O104 : H4 strain corresponded closely. This finding suggested an epidemiological link between the Polish STEC O104 : H4 isolates and the international outbreak. Retrospective serological investigations proved person-to-person transmission of the epidemic STEC O104 : H4 strain from a father who had visited Dortmund, Germany, to his 7-year-old son in Gizycko, Poland. To the best of our knowledge, this is the first report of household transmission of Shiga-toxin-producing E. coli in Poland.

Plasmid-borne 16S rRNA methylase ArmA in aminoglycoside-resistant Klebsiella pneumoniae in Poland.

We characterized 17 clinical isolates of Klebsiella pneumoniae producing 16S rRNA methylase ArmA. The isolates originated in Poland from 2002 to May 2010 and encompassed four XbaI-PFGE clusters. All the isolates were resistant to amikacin, gentamicin and kanamycin (MIC range: 256-1024 mg l(-1)) and carried the armA gene on a large plasmid of approximately 90 or 130 kb in 15 and 2 isolates, respectively. The armA gene was found in a ~10 kb ClaI restriction fragment of the large plasmid and was flanked by the same elements as in Tn1548. All the isolates carried the bla(CTX-M) gene for a CTX-M-type extended-spectrum ß-lactamase. Our results show that ArmA has disseminated horizontally among K. pneumoniae isolates in Poland on the ~90 kb plasmid of the pCTX-M3 family.

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.

[Molecular investigation of enteroaggregative, shiga toxin-producing E. coli O104:H4 isolated in Poland during the recent international outbreak--characteristic of epidemic clone]. / Ognisko wywolane przez enteroagregacyjny i werotoksyczny szczep Escherichia coli O104:H4 w Europie--postepowanie diagnostyczne w Polsce oraz charakterystyka szczepu.

Since early May 2011 a large food-borne outbreak caused by E. coli O104:H4 affected Germany then spread over 13 European countries, U.S.A. and Canada. The outbreak strain was found to possess an unusual combination of enteroaggregative E. coli pathotype with StxII. In this report we described the molecular investigation of epidemic clone in Poland during the international outbreak. We confirmed three cases of E. coli O104:H4 infections. The molecular characteristics of the Polish E. coli O104:H4 isolates including virulence profile, antimicrobial resistance, PFGE and plasmids profiles were corresponded with Germany outbreak strains.

[Analysis of the genetic background and mechanisms of dissemination of resistance to tetracycline of the Polish population of Campylobacter strains isolated in Poland in years 2007-2008]. / Analiza podloza genetycznego i mechanizmów rozprzestrzeniania sie opornosci na tetracykline populacji szczep6w z rodzaju campylobacter izolowanych w Polsce w latach 2007-2008.

In Poland, constant rise of number of Campylobacter strains resistant to tetracycline is observed in Poland. Analysis of the resistant strains showed their strong diversity, including both the different levels of resistance to this drug, large differences in the sequence of the resistant gene tetO, and diverse phylogenetic origin. The study also confirmed the important role of horizontal spread of resistance which, in the event of such a large diversity of resistant strains, can cause further very rapid escalation of resistance of Campylobacter to tetracycline.

[Occurrence of 16s rRNA methylase ArmA producing Enterobacteriaceae in a general hospital in Warsaw, Poland]. / Wystepowanie w jednym z warszawskich szpitali paleczek Enterobacteriaceae wytwarzajacych 16s rRNA metylaze Arma.

Resistance to gentamicin, amikacin and kanamycin was screened in 270 clinical isolates of Enterobacteriaceae originated from April 19 to May 19, 2010 in a regular hospital in Warsaw, Poland. Most of the isolated bacteria were considered pathogenic. Nineteen isolates (7%) were simultaneously resistant to two or three of the tested aminoglycosides. MICs of the three aminoglycosides ranged form 128 to 1024 mcg/ml for six isolates. These isolates were suspected to produce 16S rRNA methylase. Genes encoding for three methylases reported in Europe: ArmA, RmtB and RmtC were searched by PCR. The armA gene was detected in all of the six isolates. This group encompassed Enterobacter cloacae (n=4), Klebsiella pneumoniae (n=1) and Proteus mirabilis (n=1). Five isolates of this group carried the bla(CAX-M) gene for CTX-M type ESBL. The remaining isolate E. cloacae DM0340 was ESBL negative and lacked bla(CRX-M) that may suggest an altered genetic environment of the armA gene in this isolate. Our results showed that 2.2% of the tested isolates produced 16S rRNA methylase ArmA. This finding may argue for a high incidence of ArmA producing Enterobacteriaceae in Poland when compared to reports from other European countries.

[Aminoglycoside resistance in Enterobacteriaceae originated in a gynecology-obstetrical hospital: a survey for 16s rRNA methylases: ArmA, RmtB and RmtC]. / Opornosc paleczek Enterobacteriaceae wyosobnionych w szpitalu polozniczo- ginekologicznym na wybrane antybiotyki aminoglikozydowe ze szczególnym uwzgludnieniem zdolnosci do wytwarzania 16s rRNA metylaz ArmA, RmtB i RmtC.

We examined the resistance of 2359 clinical isolates of Enterobacteriaceae to gentamicin, amikacin, netilmicin and neomycin by the disc-diffusion assay. The isolates originated from female-patients and newborn infants in a gynecology-obstetrical hospital in Warsaw, Poland. Isolates from adults predominated. Most of the isolated bacteria were considered non-pathogenic, colonization flora. The majority (above 95%) of the isolates were sensitive to all of the tested aminoglycosides. Forty five (1,90%) isolates were resistant to one or more agents. In this group, E. coli was prevalent (73,33%). As little as 14 isolates had no growth inhibition around the gentamicin disc (10 mcg) (contact-growth). MICs of seven isolates ranged from 256 to 1024 (mcg/ml) of the tested agents. One isolate had MIC 1024 for amikacin and kanamycin. All the contact-growth isolates were examined for genes encoding for TEM, SHV and CTX-M beta-lactamases, and genes armA, rmtB and rmtC for 16S rRNA methylases reported in Europe. All of them produced TEM enzyme while SHV and CTX-M was expressed by one and two isolates respectively. None of the tested 16S rRNA methylases was detected. Our results show the low carriage of the aminoglycoside-resistant Enterobacteriaceae in healthy pregnant-women and most probably their sexual partners. Our findings may argue that production of the 16S rRNA methylases is still limited to patients with a long-term antibiotic-therapy in regular hospitals rather than to non-hospitalized population in Poland.