Late-onset bloodstream infections of Very-Low-Birth-Weight infants: data from the Polish Neonatology Surveillance Network in 2009-2011.

BACKGROUND: Late-Onset Bloodstream Infections (LO-BSI) continue to be one of the most important complications associated with hospitalization of infants born with very low birth weight (VLBW). The aims of this study were to assess the epidemiology of LO-BSI together with the risk factors and the distribution of causative pathogens at six Polish neonatal intensive care units that participated in the Polish Neonatology Surveillance Network from January 1, 2009 to December 31, 2011. METHODS: The surveillance covered 1,695 infants whose birth weights were <1501 grams (VLBW) in whom LO-BSI was diagnosed >72 hours after delivery. Case LO-BSI patients were defined according to NeoKISS. RESULTS: Four hundred twenty seven episodes of LO-BSI were diagnosed with a frequency of 25.3% and an incidence density of 6.7/1000 patient-days (pds). Results of our multivariate analysis demonstrated that surgical procedures and lower gestational age were significantly associated with the risk of LO-BSI. Intravascular catheters were used in infants with LO-BSI significantly more frequently and/or for longer duration: Central venous cathters (CVC) (OR 1.29) and Peripheral venous catheters (PVC) (OR 2.8), as well as, the total duration of total parenteral nutrition (13 vs. 29 days; OR 1.81). Occurrence of LO-BSI was significantly associated with increased the length of mechanical ventilation (MV) (OR 2.65) or the continuous positive airway pressure (CPAP) (OR 2.51), as well as, the duration of antibiotic use (OR 2.98). The occurrence of more than one infection was observed frequently (OR 9.2) with VLBW with LO-BSI. Microorganisms isolated in infants with LO-BSI were dominated by Gram-positive cocci, and predominantly by coagulase-negative staphylococci (62.5%). CONCLUSIONS: Independent risk factor for LO-BSI in VLBV infants are: low gestational age and requirement for surgery. The incidence rates of LO-BSI especially CVC-BSI were higher in the Polish NICUs surveillance than those of other national networks, similar to the central- and peripheral utilization ratio.

Prevalence of antibiotic resistance in multi-drug resistant coagulase-negative staphylococci isolated from invasive infection in very low birth weight neonates in two Polish NICUs.

BACKGROUND: Multi-drug resistant coagulaso-negative staphylococci (CNS) have become an increasing problem in nosocomial infections connected with the presence of medical devices. The paper aimed to analyze the prevalence of antibiotic resistance in CNS isolated from invasive infection in very low birth weight (VLBW) neonates. METHODS: Continuous prospective target surveillance of infections was conducted in 2009 at two Polish NICUs that participated in the Polish Neonatology Surveillance Network (PNSN). The study covered 386 neonates with VLBW (≤1500 g), among which 262 cases of invasive infection were detected with predominance of CNS (123; 47%). Altogether, 100 CNS strains were analyzed. The resistance phenotypes were determined according to EUCAST. Resistance genes: mecA, ermA, ermB, ermC, msrA, aac(6')/aph(2''), ant(4')-Ia and aph(3')-IIIa were detected using multiplex PCR. RESULTS: The most common species was S. epidermidis (63%), then S. haemolyticus (28%) and other CNS (9%). Among S. epidermidis, 98% of isolates were resistant to methicillin, 90% to erythromycin, 39% to clindamycin, 95% to gentamicin, 60% to amikacin, 36% to ofloxacin, 2% to tigecycline, 3% to linezolid and 13% to teicoplanin. Among S. haemolyticus isolates, 100% were resistant to methicillin, erythromycin and gentamicin, 18% to clindamycin, 50% to amikacin, 86% to ofloxacin, 14% to tigecycline and 4% to teicoplanin. No resistance to linezolid was detected for S. haemolyticus isolates. Moreover, all isolates of S. epidermidis and S. haemolyticus were susceptible to vancomycin. The mecA gene was detected in 98% of S. epidermidis isolates and all of S. haemolyticus ones. Among macrolide resistance isolates, the ermC was most common in S. epidermidis (60%) while msrA was prevalent in S. haemolyticus (93%). The ermC gene was indicated in all isolates with cMLSB, whereas mrsA was found in isolates with MSB phenotype. Of the aminoglycoside resistance genes, aac(6')/aph(2'') were present alone in 83% of S. epidermidis, whereas aac(6')/aph(2'') with aph(3')-IIIa were predominant in 84% of S. haemolyticus. CONCLUSIONS: Knowing the epidemiology and antibiotic resistance of CNS isolated from invasive infection in VLBW neonates is a key step in developing targeted prevention strategies and reducing antibiotic consumption.

Morphometric studies of Leydig cells in chinchillas (Chinchilla lanigera) during high and low fertility seasons.

The aim of this study was to examine morphometric data of Leydig cells of 10 male chinchillas. Testes, cut into 5-microm thick sections, were stained using the p.a.S. and Masson's methods. Some 3800 Leydig cells have been evaluated. Their dimensions, as well as the diameters of their nuclei and the distances of the nuclei from the boundaries of the cells, have been measured. The areas of the surface and volumes of the nuclei of Leydig cells have been calculated, as well as the areas of the surface of the Leydig cells themselves. The following data have been obtained. The Nuclei of Leydig Cells. The largest diameters: longer cells - 12 microm; shorter cells - 10 microm. Mean diameters: longer cells - 5.67 +/- 3.44 microm, shorter cells - 4.45 +/- 3.44 microm. The largest surface area - 120 microm2, the mean surface area - 28.27 +/- 11.21 microm2. The largest volume - 1200 microm3, the mean volume of nucleus - 171.8 +/- 65.82 microm3. Mean distances of Leydig cell nuclei from the opposite boundaries of the cells amounted to 1.29 +/- 1.41 microm, 4.24 +/- 2.39 microm, 4.09 +/- 2.23 microm, 6.12 +/- 2.33 microm. Leydig cells. The largest diameters: longer cells - 24 microm, shorter cells - 22 microm. Mean dimensions: longer cells - 13.86 +/- 2.76 microm, shorter cells - 10.89 +/- 2.44 microm. The largest area of surface - 528 microm2, the mean area of surface - 155.44 +/- 59.78 microm2. Morphometric analysis confirmed cytologic observations that the shape of the nuclei of Leydig cells is somewhat ellipsoidal. The nuclei are located off-centre and are not situated in the greatest agglomeration of cytoplasm. The shape of Leydig cells is irregular. The obtained results may provide insight on the infertility of chinchilla males, as well as in research on the annual cyclic fertility of these animals. They may be put to use in practice for the purpose of improving breeding of this species.

Pregnancy detection in putatively unmated mink (Mustela vison) by serum progesterone level.

The aim of this study was to determine whether blood plasma progesterone is a reliable indicator of pregnancy in mink at an early stage of gestation. We also attempted to establish the threshold value of progesterone as a pregnancy indicator. The analysis was carried out at a production farm on 42 standard female mink aged 1 year, which were grouped both according to the observed success of mating ("mated" and "unmated") and the level of blood serum progesterone measured afterwards ("pregnant" and "nonpregnant"). It was next verified whether a particular female had been assigned to the proper group in the first place. An analysis of accuracy of mating success assessment within the group of unmated females revealed that more than one-third of decisions were wrong, since some females that had been considered unmated ultimately whelped. This suggests that mating supervision by farm workers lacks reliability. A progesterone test for verification of such management decisions should limit the risk of err,or. We suggest that progesterone tests could be carried out using the threshold values 1.9 ng/ml and 20 ng/ml in blood sampled on 25 March and 8 April, respectively, although some level of uncertainty should be taken into account.

[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.

Plasma concentration of calcium, magnesium and phosphorus in chinchilla with and without tooth overgrowth.

The aim of the study was to identify the causes underlying overgrowth of incisors in chinchillas through an analysis of selected plasma electrolyte concentrations, with particular consideration of minerals involved in the formation of osseous tissue, i.e., Ca, Mg, and P. The analysis involved 40 female standard chinchillas managed in a commercial farm system, aged 2 to 4 years, divided into two groups of 20 individuals each: D--chinchillas with incisor overgrowth and C--controls with normal dentition. Concentrations of Ca, Mg, and P were measured in blood plasma. The analysis was carried out using ICP OES (inductively coupled plasma optical emission spectrometry) by means of the Optima 2000 DV instrument (Perkin Elmer). The resulting data were analysed statistically using one-way ANOVA with Duncan's range test. The results show that abnormal metabolism of dental tissue minerals, especially Ca and P, cannot be excluded as the cause of tooth overgrowth in chinchilla.

Season controlled reproduction of undomesticated animals.

The following article is a summary of research on the influence of season on the reproductive processes in undomesticated animals. The results presented below show: a/ an annual hormonal profile of domestic pig and wild boar crossbreed and the antioxidant blood system in the different seasons, b/ the possibility of gonadptropic hormone stimulation in chinchillas which are in diestrus or infertile, c/ the possibility of using bison's semen (collected post mortem from the epididymis) for cryoconservation.