Evaluation of the Carba NP test for carbapenemase detection in Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp., and its practical use in the routine work of a national reference laboratory for susceptibility testing.

The aim of this study was to evaluate the Carba NP test (and CarbAcineto) for the detection of carbapenemases in Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp., and to assess its usefulness in the routine work of the National Reference Centre for Susceptibility Testing (NRCST) in Poland. The evaluation of the Carba NP/CarbAcineto tests was carried out on a group of 81 Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. isolates producing KPC-, NDM-, VIM-, IMP- or OXA-48, -23, -24/40, -58-type carbapenemases, and on 26 carbapenemase-negative strains cultivated on a broad panel of microbiological media. Subsequently, the performance of the Carba NP/CarbAcineto tests was assessed on 1282 isolates of Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. from Polish hospitals, submitted to the NRCST during a 9-month period in 2014. The Carba NP/CarbAcineto results were compared with other phenotypic tests and/or polymerase chain reaction (PCR). The impact of the media on the results of the Carba NP/CarbAcineto tests was observed, with the Columbia blood agar yielding the highest sensitivity and clarity of the results. Furthermore, the Carba NP/CarbAcineto tests were included in the NRCST routine procedure for carbapenemase identification. The sensitivity and specificity of the Carba NP test were 95.8% and 93.3%, respectively, for Enterobacteriaceae, and 97.5% and 99.0%, respectively, for Pseudomonas spp. The sensitivity of the CarbAcineto test for Acinetobacter spp. was 88.9%. This study confirmed the usefulness of the Carba NP/CarbAcineto tests for the rapid detection of various types of carbapenemases.

Prevalence of Neisseria meningitidis Carriage with Identification of Serogroups and Genogroups in Professional Soldiers.

The article presents the prevalence of Neisseria meningitidis carriage with the identification of sero- and genogroups in professional soldiers serving in the Polish Armed Forces. A total of 1246 soldiers from the 10th Armored Cavalry Brigade in Swietoszów, Poland were examined in the period January-February 2016. Microbiological tests were performed using standard methods (culture, incubation, microscopy, biochemical, and automated identification with VITEK cards). Neisseria meningitidis isolates from carriers were subjected to a slide agglutination test for the identification of serogroups, next bacterial DNA was isolated and genogroups were identified based on the results of PCR. Of the 1246 soldiers tested, 65 were found to be carriers of N. meningitidis. Serogroups of 36 isolates and genogroups of 56 meningococcal isolates were determined. The genogrouping identified the isolates as belonging to group B (n = 34; 52.3 %), E29 (n = 8; 12.3 %), C (n = 6; 9.2 %), Y (n = 6; 9.2 %), and W (n = 2; 3.1 %). The primers which were used did not make it possible to determine the genogroup of nine isolates. In conclusion, the overall carrier rate of N. meningitidis amounted to 5.2 %, with the serogroup B being predominant, which is similar to that reported in the general population in Poland and Central Europe.

Streptococcus suis in invasive human infections in Poland: clonality and determinants of virulence and antimicrobial resistance.

The purpose of this study was to perform an analysis of Streptococcus suis human invasive isolates, collected in Poland by the National Reference Centre for Bacterial Meningitis. Isolates obtained from 21 patients during 2000-2013 were investigated by phenotypic tests, multilocus sequence typing (MLST), analysis of the TR9 locus from the multilocus variable number tandem repeat (VNTR) analysis (MLVA) scheme and pulsed-field gel electrophoresis (PFGE) of SmaI-digested DNA. Determinants of virulence and antimicrobial resistance were detected by polymerase chain reaction (PCR) and analysed by sequencing. All isolates represented sequence type 1 (ST1) and were suggested to be serotype 2. PFGE and analysis of the TR9 locus allowed the discrimination of four and 17 types, respectively. Most of the isolates were haemolysis- and DNase-positive, and around half of them formed biofilm. Genes encoding suilysin, extracellular protein factor, fibronectin-binding protein, muramidase-released protein, surface antigen one, enolase, serum opacity factor and pili were ubiquitous in the studied group, while none of the isolates carried sequences characteristic for the 89K pathogenicity island. All isolates were susceptible to penicillin, cefotaxime, imipenem, moxifloxacin, chloramphenicol, rifampicin, gentamicin, linezolid, vancomycin and daptomycin. Five isolates (24 %) were concomitantly non-susceptible to erythromycin, clindamycin and tetracycline, and harboured the tet(O) and erm(B) genes; for one isolate, lsa(E) and lnu(B) were additionally detected. Streptococcus suis isolated in Poland from human invasive infections belongs to a globally distributed clonal complex of this pathogen, enriched in virulence markers. This is the first report of the lsa(E) and lnu(B) resistance genes in S. suis.

Effectiveness of immunoprophylaxis in suppressing carriage of Neisseria meningitidis in the military environment.

Neisseria meningitidis, etiological factor of invasive meningococcal disease, is a human commensal that colonizes the nasopharynx. Colonization is usually asymptomatic, but it is a prerequisite for disease. Asymptomatic carriers are the major source of infection. In the present study, a survey of N. meningitidis carriage was conducted between January and March 2013 in a military unit in Poland. Single-time throat culture samples were collected from professional 559 soldiers (302 unvaccinated vs. 257 vaccinated individuals with the quadrivalent conjugate vaccine ACYW-135). Bacterial identification was performed with classic microbiological methods (culture, incubation, identification). Non-culture method (PCR) was used for confirmation of detected strains of N. meningitidis and determination of serogroups. We found 29 carriers in the group of unvaccinated soldiers (9.6 % of examined individuals) whereas among vaccinated soldiers only 3 persons were carriers of N. meningitidis (1.2 %). The most frequently identified serogroups among the carriers serving in the same military facility were serogroup B (28 %), followed by Y (25 %), and C (22 %). In conclusion, the initiation of mass vaccination with the quadrivalent conjugate vaccine ACYW-135 in the military environment seems an effective method of suppressing N. meningitidis carriage.

Recent trends in epidemiology of invasive pneumococcal disease in Poland.

The objectives of this study were to assess the current incidence of invasive pneumococcal disease (IPD) in Poland (2011-2013), where mass vaccination has not been implemented, and to characterize the Streptococcus pneumoniae isolates responsible for invasive infections by determining their serotype distribution and antimicrobial resistance patterns. For all isolates identification, serotyping and antimicrobial minimal inhibitory concentrations determination were performed based on routine techniques. The highest incidence rates were observed among adults older than 85 years old (4.62/100,000) and children under 1 year of age (4.28/100,000). The general case fatality ratio (CFR) was 25.4%, with the highest CFR in the age group ≥85 years old (59.7%). The most common serotypes were 3, 14, 19A, 4, 9V, 19F, 1, and 23 F (61.3% of all isolates). The 10- and 13-valent pneumococcal conjugated vaccines (PCV) covered 46.0 and 71.8% of all IPD cases, 61.4 and 79.5% of cases in children under two years, and 60.4 and 78.6% of cases involving children under five years of age, respectively. The PCV13 and 23-valent polysaccharide vaccine covered 68.7 and 86.0% of cases in adults >65 years old, respectively. Decreased susceptibility was noted for penicillin (24.8%), cefotaxime (10.0%), meropenem (5.0%), rifampicin (0.8%), chloramphenicol (4.3%), erythromycin (29.7%) and clindamycin (25.6%). Multi-drug resistance characterized 21.6% of the pneumococci tested. Despite deficiencies in the Polish surveillance system and strong underestimation of IPD cases, results of the study showed good theoretical coverage of PCV, which should encourage inclusion of anti-pneumococcal conjugate vaccine into the national immunization program.

Heart function in magnetic resonance imaging and the mesenteric artery reactivity in rats receiving lead-contaminated drinking water.

The aim of this study was to evaluate the effect of lead (Pb)-contaminated drinking water on magnetic resonance imaging (MRI)-estimated cardiac function, vascular reactivity, and serum lipids in rats. For 3 months, male Wistar rats, aged 4-6 weeks, were given drinking water with the addition of lead acetate at a concentration of 100 ppm Pb (10 rats) or water free from Pb (8 control rats). The cardiac MRI was performed at rest and under ß-adrenergic stimulation on a 4.7 T scanner using electrocardiogram-triggered gradient echo (FLASH) cine sequence. After 1-2 weeks of the MRI test, experiments were performed ex vivo. After stabilization of perfusion pressure (PP), norepinephrine at doses from 0.01 to 5.0 µg was dissolved in Krebs solution, injected in a volume of 100 µl, and next infused at a concentration of 0.5 µg/ml into the isolated mesenteric artery. In this manner, preconstricted mesenteric bed was used to determine PP changes induced by acetylcholine, given at doses from 0.05 to 5.0 µg, before and during the infusion of nitric oxide synthase inhibitor (1.0 µg/ml). At the end, dobutamine (5 mg), followed by potassium chloride (10.5 mg), was injected. Lipid levels were determined enzymatically, blood Pb level was measured by the atomic absorption spectrophotometer. This study showed that Pb impairs the left ventricular systolic and diastolic function. Pb-induced changes in response to resistance of vessels to vasoactive agents may be secondary to the reduced left ventricular ejection fraction. The high-density lipoprotein subfraction 2 (HDL2) is involved in the cardiovascular effect of Pb.

Molecular characterization of resistance to rifampicin in clinical isolates of Neisseria meningitidis.

Among 3904 meningococcal isolates collected between October 2002 and June 2007 by the French Meningococcal Reference Centre, eight (0.20%) were resistant to rifampicin (Rif-R; MIC >1 mg/L) and 27 (0.69%) were intermediate-resistant to rifampicin (Rif-I; MICs between 0.38 mg/L and 1 mg/L) according to the E-test method. The MICs determined by agar dilution were lower, eliminating the E-test intermediate category. All Rif-R isolates had mutations in the rpoB gene, resulting in substitutions at or near amino acid position 552, which were absent in non-resistant isolates. These data suggest that a rifampicin clinical breakpoint of 1.0 mg/L should be adopted for Neisseria meningitidis.

Acute iron poisoning in adult female.

We report a case of a 27-year-old female with anemia, treated with high dose oral and parenteral iron therapy (within 20 days, the patient received a total dose of 4 g Fe+2 orally and 700 mg Fe+2 iv and im), and developed clinical manifestations characteristic of acute iron poisoning. Initial gastrointestinal symptoms and hypotension were followed by signs of mitochondrial toxicity: high leucocytosis, shock, multi-organ failure and disseminated intravascular coagulation. We discuss the difficulties in diagnosing acute iron poisoning. The initial low total iron blood capacity and high ferritin level, as well as the typical sequence of symptoms, supported the diagnosis. The patient avoided fatal consequences, probably due to the administration of iron doses over an extended period of time. However, cumulative effects led to the apparent iron toxicity. After 2 weeks of treatment, the patient was discharged from hospital in good condition. Human & Experimental Toxicology (2007) 26, 663-666.

Resistance patterns of selected respiratory tract pathogens in Poland.

This study presents the results of a survey of the in-vitro susceptibility to antimicrobial agents of major pathogens responsible for community-acquired respiratory tract infections in Poland during 2002-2004. The collection of 1184 bacterial isolates comprised 398 Streptococcus pneumoniae, 344 Haemophilus influenzae, 302 Streptococcus pyogenes and 140 Moraxella catarrhalis. Among the pneumococcal isolates, 16.8% were penicillin-non-susceptible (PNSP), of which 80.6% were identified as multidrug-resistant. Overall, 9.0% of H. influenzae isolates were beta-lactamase-positive, although this percentage increased noticeably in the third year of the study. Based on PCR results, 12.8% of H. influenzae isolates were identified as low-level beta-lactamase-negative, ampicillin-resistant (BLNAR), and one isolate as low-level beta-lactamase-positive, amoxycillin-clavulanic acid-resistant (BLPACR). Pulsed-field gel electrophoresis (PFGE) classified 45 H. influenzae isolates with altered penicillin-binding proteins into 15 PFGE types, including two predominant types (with four and six sub-types) containing 15 and ten isolates, respectively. Resistance to tetracycline, erythromycin and clindamycin was found in 20.9%, 8.9% and 4.6% of S. pyogenes isolates, respectively. The production of beta-lactamase characterised 91.4% of M. catarrhalis isolates. In summary, the overall occurrence of PNSP in Poland remains stable, although there was a noticeable increase in the proportion of fully-resistant isolates. A rising trend in the prevalence of beta-lactamase producers and low-level BLNAR isolates was observed among Polish isolates of H. influenzae.

Characterisation of Neisseria meningitidis C:2b:P1.2,5 isolates in Poland.

This study aimed to characterise Neisseria meningitidis C:2b:P1.2,5 isolates from Poland, which have now become predominant among serogroup C isolates in this country. Overall, 44 isolates (25 invasive and 19 from contact carriers) were typed by whole-cell ELISA and pulsed-field gel electrophoresis. Additionally, the invasive isolates were analysed by multilocus sequence typing, which revealed that they all belonged to the ST-8 complex/cluster A4. The emergence of this clone in other countries has resulted in mass immunisation campaigns and has been associated with a higher level of decreased susceptibility to penicillin; however the present study detected only one isolate that was penicillin-non-susceptible.

The impact of subchronic cadmium poisoning on the vascular effect of nitric oxide in rats.

The aim of this study was to evaluate the impact of poisoning with cadmium in hypertensive doses (50 or 200 ppm in drinking water for three months) on the basal and stimulated release NO effect in the isolated and perfused rat mesenteric bed. Mesenteric artery preparation preconstricted by norepinephrine (0.5 microg/mL) was used to determine changes in its vascular resistance induced by e-NOS synthase blocker, N-omega-nitro-L-arginine (L-NOARG) injected in increasing doses from 1.0 to 200.0 microg or acetylcholine (ACh) administered in doses from 0.05 x 10(-10) to 5.0 x 10(-10) mol before and during L-NOARG infusion (1.0 microg/mL). Vascular reactivity was measured as an increase or decrease in perfusion pressure in the constant flow system. Rats poisoned with 50 or 200 ppm of cadmium demonstrated a significant decrease (P <0.05) in vascular response to L-NOARG used in doses of 50 or 100 microg. The dose-response curve obtained for L-NOARG was shifted to the right and ED50 value was greater in the group of rats given cadmium in a dose of 200 ppm than in the controls (70.3 +/- 10.7 versus 25.7 +/- 4.8 microg, P <0.01). These rats reacted with lower expressed vasodilatation to ACh in doses to 0.2 x 10(-10) mol. In all poisoned rats, L-NOARG enhanced the effect of ACh used in doses from 0.05 to 0.5 x 10(-10) mol, whereas in the control group this effect was only achieved at 0.1 x 10(-10) mol. The serum nitric oxide concentration was decreased (P <0.05) in both groups of cadmium-treated rats. These results suggest that cadmium in hypertensive doses modifies the vascular effect of NO in basal conditions and after stimulation by ACh.

Identification of Neisseria meningitidis sequence type 66 in Poland.

Investigation of two cases of invasive meningococcal disease within a single family revealed the presence of isolates of Neisseria meningitidis phenotype C:2b:P1.2,P1.5 belonging to sequence type (ST) 66. The ST66 clone is a single-locus variant of the widely distributed ST8 complex, which has been observed previously in Spain, Belgium, Australia and New Zealand. This hypervariable meningococcal lineage has been responsible for local epidemics worldwide. This is the first report of ST66 meningococcal isolates of this phenotype from Poland.

Lead-cadmium interaction effect on the responsiveness of rat mesenteric vessels to norepinephrine and angiotensin II.

The comparison of the reactivity to norepinephrine (NE) and angiotensin II (A II) of isolated mesenteric blood vessels obtained from rats simultaneously poisoned with lead and cadmium to those responses of rats treated singly with lead or cadmium was performed. Male Buffalo rats aged 6-8 weeks were administered intragastrically with lead (35 mg Pb/kg body wt.) and/or cadmium (5 mg Cd/body wt.), once a week for a period of 7 weeks. Control rats were given equimolar amounts of sodium acetate and/or sodium chloride. Changes in mesenteric vascular resistance due to NE and A II injections were measured ex vivo as an increase in perfusion pressure in vessels prepared by McGregor's method. The dose-response curve for NE (0.01-5.0 microg) determined for vessels of rats poisoned simultaneously with lead and cadmium was shifted to the left in comparison to controls (not poisoned rats), similarly to these determined for rats poisoned with lead or cadmium. ED(50) NE pointed out in the control group (0.83+/-0.5 microg) was significantly greater than in metal treated groups (0.44+/-0.09; 0.45+/-0.26 and 0.5+/-0.11 microg in lead, cadmium, lead and cadmium-treated rats, respectively). This study indicated a tachyphylaxis in responses of isolated mesenteric vessels to A II injected in increasing doses, and the weaker, in comparison to controls, response of vessels of rats poisoned with lead and/or cadmium to A II at a dose of 0.4 microg. The decreasing response to A II could result from changes in calcium ions transport through L-type channels in vascular smooth muscle cells, because verapamil (2.0 microM) inhibited the A II-induced vasoconstriction more weakly in rats poisoned with metals than in controls. Inhibitor of prostaglandins synthesis, ketoprofen (200 microg/ml per min.) attenuated the pressor effect of NE in blood vessels obtained from all rats, but this effect was less potent in arteries of cadmium poisoned rats. Ketoprofen also inhibited the vasoconstrictory action of A II in all groups, but this effect was lower in vessels of rats poisoned simultaneously with lead and cadmium. We suggest that the release of vasoactive prostaglandins as a consequence of endothelial angiotensin receptor stimulation changes more under the influence of metals administered to rats simultaneously than under the influence or lead or cadmium administered singly. Treatment with a nitric oxide synthase inhibitor (L-NOARG; 22 microg/ml per min.) potentiated a NE-induced pressor response in all groups. However, the increase in perfusion pressure was greater in rats poisoned with cadmium in comparison to controls. L-NOARG potentiated the A II induced vasoconstriction only in cadmium poisoned rats, also indicating a greater influence of nitric oxide in cadmium treated rat vasculature. Two-way ANOVA showed the existence of lead-cadmium interactions effects on the reactivity of rat isolated mesenteric vessels to NE, A II and papaverine.

[Activity of cefepime compared with other antibiotics against major hospital bacterial pathogens]. / Aktywnosc cefepimu w porównaniu z innymi antybiotykami wobec glównych bakteryjnych patogenów szpitalnych.

The aim of the study was to evaluate susceptibility of 976 bacterial isolates from nosocomial infections to cefepime and 9 other antibiotics used in the treatment of hospitalised patients. Bacterial strains were mainly derived from wound and soft tissue infections, sputum, abscesses and blood. The most prevalent etiologic agents were: Pseudomonas aeruginosa (18.7%), Escherichia coli (13.8%), Staphyloccocus aureus (9.7%, Acinetobacter baumannii (9.12%), Klebsiella pneumoniae (7.38%), Enterobacter cloacae (5.6%). The most susceptible to cefepime were strains of K. pneumoniae (98.62%), E. coli (98.52%) and E. cloacae (98.19%) including those producing extended spectrum beta-lactamases. The degree of susceptibility to cefepime was equal to that of imipenem. A. baumannii was the least susceptible species (67.42%). This study indicate that cefepime may play an important role in therapy of nosocomial infections in particular caused by Enterobacteriace.

[High density lipoprotein cholesterol level in rats poisoned with cadmium]. / Zawartosc cholesterolu w lipoproteinach o duzej gestosci u szczurów zatruwanych kadmem.

The effect of cadmium on lipid metabolism in persons occupationally and environmentally exposed to this metal may lead to the occurrence of cardiovascular diseases. The disturbances of the reverse transport of cholesterol could be responsible for the vascular changes. The aim of this study was to evaluate the impact of cadmium on the cholesterol level in the main fraction and subfractions of high density lipoprotein (HDL). The cholesterol level was measured in serum of rats treated with cadmium in a weekly dose of 5 mg/kg b.w. for seven weeks and in controls. After a seven-week exposure, the decreased HDL2, and the increased HDL3 cholesterol levels were observed in cadmium-poisoned animals as compared to controls. The results of the study suggest that a cadmium-impaired mechanism of the cholesterol transport in blood may induce vascular changes.

[Is there any risk interaction between electromagnetic field generated by mobile phones and artificial pacemakers]. / Czy pole elektromagnetyczne wytwarzane przez telefonie komórkowa powoduje zaklócenia w dzialaniu sztucznych stymulatorów serca?

Electromagnetic noise is rapidly increasing in the environment. Electromagnetic fields (EMF) originating from a variety of different sources have been shown to interfere with the function of implanted cardiac pacemaker. The authors present the effect of EMF generated by wireless telephones on different types of artificial pacemakers. In addition, instructions on safe use of mobile phones addressed to people with implanted artificial pacemaker are provided.