Antimicrobial resistance development following surgical site infections.

Surgical site infections (SSIs) determine an increase in hospitalization time and antibiotic therapy costs. The aim of this study was to identify the germs involved in SSIs in patients from the Clinical Emergency County Hospital of Craiova (SCJUC) and to assess their resistance to antimicrobials, with comparisons between surgical wards and the intensive care unit (ICU). The biological samples were subjected to classical bacteriological diagnostics. Antibiotic resistance was tested by disc diffusion. We used hierarchical clustering as a method to group the isolates based upon the antibiotic resistance profile. The most prevalent bacterial species isolated were Staphylococcus aureus (S. aureus; 50.72%), followed by Escherichia coli (E. coli; 17.22%) and Pseudomonas aeruginosa; 10.05%). In addition, at lower percentages, we isolated glucose-non-fermenting, Gram-negative bacteria and other Enterobacteriaceae. The antibiotic resistance varied greatly between species; the most resistant were the non-fermenting Gram­negative rods. E. coli exhibited lower resistance to third generation cephalosporins, quinolones and carbapenems. By contrast, Klebsiella was resistant to many cephalosporins and penicillins, and to a certain extent to carbapenems due to carbapenemase production. The non-fermenting bacteria were highly resistant to antibiotics, but were generally sensitive to colistin. S. aureus was resistant to ceftriaxone (100%), penicillin (91.36%), amoxicillin/clavulanate (87.50%), amikacin (80.00%) and was sensitive to levofloxacin, doxycycline, gentamycin, tigecycline and teicoplanin. The Enterobacteriaceae resistance was only slightly higher in the ICU, particularly to carbapenems (imipenem, 31.20% in the ICU vs. 14.30% in the surgical wards; risk ratio = 2.182). As regards Staphylococcus species, but for non-fermenting bacteria, even if the median was almost the same, the antibiotic resistance index values were confined to the upper limit in the ICU. The data gathered from this study may help infection control teams to establish effective guidelines for antibiotic therapies in various surgical procedures, in order to minimize the risk of developing SSIs by the efficient application of the anti-infection armamentarium.

Histochemical and immunohistochemical evidence of tumor heterogeneity in colorectal cancer.

INTRODUCTION: Intratumoral heterogeneity implies the existence of differences between tumor cells, which can best be shown by histochemical and immunohistochemical techniques. The histological study is a mandatory step in any research aimed at characterizing tumor heterogeneity. Immunohistochemistry (IHC) also plays an important role in the differentiation of tumor types, assessing aggressiveness. MATERIALS AND METHODS: Investigated group consisted of 50 patients with colorectal adenocarcinoma, for each were recorded clinicopathological data and harvested samples intraoperatively, which were included in paraffin blocks. We perform Hematoxylin-Eosin staining for histological grade and other indices. IHC study used Avidin-Biotin-Peroxidase (ABC), with the markers: CK7, CK20, MUC1, MUC2, Ki-67, PCNA, p53, KRAS, BCL2, PTEN, EGFR. The resulting data were analyzed by statistical methods. RESULTS: Most of colorectal adenocarcinoma studied had no special histological features and had G2 grade. IHC detected in most cases the CK20+÷CK7- phenotype (78%) and MUC1 (74%) protein expression. The proliferation markers (Ki-67 and PCNA) were present in all tumor mass with a variable index, which shows high intratumoral heterogeneity, but p53 and KRAS were distributed more uniformly, showing low intratumoral heterogeneity. PTEN was expressed nuclearly in 86% of the cases and EGFR in 42%. CONCLUSIONS: The expression profiles of cytokeratins and mucins in the colorectal adenocarcinomas are useful in defining tumor phenotypes with different prognosis and therapy. We found a significant positive correlation between KRAS protein expression and BCL2 and TP53 expression. The study demonstrated the intratumoral and intertumoral heterogeneity, expressed at phenotypic level.