BackgroundMulti-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.MethodsContinuous 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.ResultsThe 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.ConclusionsKnowing 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.

BackgroundLate-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.MethodsThe 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.ResultsFour 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%).ConclusionsIndependent 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.

The aim of this study was to examine morphometric data of Leydig cells of 10 male chinchillas. Testes, cut into 5-Fm thick sections, were stained using the p.a.S. and Massons 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 Fm; shorter cells 10 Fm. Mean diameters: longer cells 5.67 ± 3.44 Fm, shorter cells 4.45 ± 3.44 Fm. The largest surface area 120 Fm , the mean surface area 28.27 ± 11.21 Fm. The largest volume 1200 Fm ! , the mean volume of nucleus 171.8 ± 65.82 Fm !. Mean distances of Leydig cell nuclei from the opposite boundaries of the cells amounted to 1.29 ± 1.41 Fm, 4.24 ± 2.39 Fm, 4.09 ± 2.23 Fm, 6.12 ± 2.33 Fm. Leydig cells. The largest diameters: longer cells 24 Fm, shorter cells 22 Fm. Mean dimensions: longer cells 13.86 ± 2.76 Fm, shorter cells 10.89 ± 2.44 Fm. The largest area of surface 528 Fm , the mean area of surface 155.44 ± 59.78 Fm. 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.

Abstract. 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.

Title of the paper: Analyze of effect selected indices on litter size of minks in relation to colour variety (short communication)The studies were carried out in 2003-2004 on a farm located in West Pomerania, Poland, with an annual production output exceeding 75,000 pelts. The breeding stock comprised 25,000 females and 4,000 males, managed in genetic groups comprising 40 females related to each other and 8 males related to each other, For the experiments, we selected at random 1769 females in 7 colour varieties: Black Cross, Buff Sapphire, Perl, Sapphire, Sprinkler, Scan Black, and Scan Brown. The following reproduction indices were analysed: litter size at birth and at weaning, litter size in relation to number of services and birth date. Moreover, all the indices were estimated in relation to the year of the female's reproduction management. The Buff Sapphire proved to be the most fertile variety, and produced 7.6 born and 7.3 weaned offspring. This result was tested statistically and the differences were highly significant compared to the Sapphire, Sprinkler, and Black Cross, which yielded 6.4-6.5 born and 5.9-6.3 weaned offspring. In the second year of reproduction management, all the varieties but Sapphire exhibited increased number of litters. The date of birth significantly affected litter size; the largest litters were obtained in the 16th week of year.