Activity of Ceftolozane/Tazobactam Against Gram-Negative Rods of the Family Enterobacteriaceae and Pseudomonas Spp. Isolated from Onco-Hematological Patients Hospitalized in a Clinical Hospital in Poland.

BACKGROUND The most common etiological agents of infections in onco-hematological patients are Gram-negative rods resistant to many antimicrobials, including carbapenems. Recently, ceftolozane combined with tazobactam became a novel therapeutic option. The aim of the present study was to analyze the susceptibility to ceftolozane/tazobactam of the clinical strains of these bacteria. MATERIAL AND METHODS Material comprised rectal swabs, urine, and bronchoalveolar lavage fluid obtained from onco-hematological patients hospitalized in a clinical hospital (1050 beds) in Poland. Identification of the isolated bacteria was done by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) using the MALDI Biotyper (Bruker). Ceftolozane/tazobactam susceptibility of the isolates was assessed using antimicrobial gradient strips (E-test, BioMérieux). Antimicrobial susceptibility testing and interpretation of the results was done according to the current recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). RESULTS In total, 281 rectal swabs and 116 urine samples were tested for the presence of Gram-negative rods producing ESBL, and 531 rectal swabs and 8 bronchoalveolar lavage fluid samples were tested for the presence of Gram-negative rods resistant to carbapenems. In the analyzed period, 69 non-repetitive strains of bacteria were isolated that were in the spectrum of activity of ceftolozane/tazobactam. Among 44 clinical strains of ESBL(+) Enterobacteriaceae rods, 76% were susceptible to ceftolozane/tazobactam. All 9 strains of non-carbapenemase-producing P. aeruginosa resistant or with decreased susceptibility to carbapenems were susceptible to ceftolozane/tazobactam. CONCLUSIONS Ceftolozane/tazobactam may be an option in the therapy of infections caused by ESBL(+) strains of Enterobacteriaceae as well as non-carbapenemase-producing carbapenem-resistant strains of P. aeruginosa.

Fournier's Gangrene: Clinical Presentation of 13 Cases.

BACKGROUND Fournier's gangrene (FG) is a fulminant form of infective, polymicrobial, necrotizing fasciitis of the perineal, genital, and perianal regions. It commonly affects men, but women and children may also develop this type of tissue necrosis. MATERIAL AND METHODS This study is a retrospective analysis of the management of 13 cases of Fournier's gangrene, diagnosed from among about 45 000 patients (men, women, and children) treated in the Department of General, Oncological, and Functional Urology (Medical University of Warsaw) from 1995 to 2013. All patients with Fournier's gangrene underwent adequate surgical debridement of the necrotic tissues. Additional procedures (suprapubic cystostomy and orchiectomy) were necessary in 10 out of 13 (77.0%) patients. Seven out of 13 (53.8%) patients required subsequent reconstructive surgery of the scrotum. RESULTS All 13 patients were males, with a median age of 59.6 years (range: 42-68 years). The average hospital stay was 31.9 days (range: 16-46 days). None of our patients died due to Fournier's gangrene. Bacteriological cultures of samples from the wounds showed polymicrobial flora, including the following genera of aerobes and anaerobes: Escherichia, Proteus, Klebsiella, Moraxella, Gemella, Enterococcus, Streptococcus, Staphylococcus, Bacteroides, Pseudoflavonifractor, Parabacteroides, Porphyromonas, Prevotella, Peptoniphilus, Peptostreptococcus, Actinomyces, Collinsella, and Lactobacillus. CONCLUSIONS Favorable outcome of FG treatment with low morbidity and no mortality can be achieved with rapid diagnosis, urgent surgical debridement of all necrotic tissues, and broad-spectrum empirical antimicrobial therapy, usually with combined antibiotics, against aerobic and anaerobic bacteria. Prevention of uroseptic shock by treating localized infection is compulsory.

Biofilm production by clinical strains of Acinetobacter baumannii isolated from patients hospitalized in two tertiary care hospitals.

Microbial biofilms are considered as virulence factors. During the present study, 34 clinical strains of Acinetobacter baumannii, isolated from patients hospitalized in two tertiary care hospitals, were examined for biofilm formation. These strains showed high variability in biofilm formation. Furthermore, no relation could be found between the ability of biofilm production and molecular type, carbapenem resistance, site of isolation of the clinical strains of A. baumannii and disease severity. Interestingly, in two cases an increase in biofilm formation could be detected in A. baumannii isolates cultured from the same patient upon prolonged hospitalization.

Multidrug-resistant bacteria isolated from patients hospitalised in Intensive Care Units.

Surveys of the prevalence and susceptibility patterns of bacterial isolates are important in determining optimum empirical therapy for infections in critically ill patients. The aim of this study was to determine possible differences in the patterns of bacterial resistance in two Intensive Care Units (ICUs) depending on the patient profile. There was a high percentage of non-fermenting Gram-negative rods (NFGNR) among the bacterial isolates from both wards. NFGNR comprised 43.8% of all isolates from ICU-B and 38.9% from ICU-A. Extended-spectrum beta-lactamase production was detected in 40.0% of Gram-negative rods cultured from ICU-A compared with 26.7% from ICU-B; whilst imipenem-resistant strains of Acinetobacter baumannii constituted 17.1% of isolates from ICU-A and 9.6% from ICU-B. Emergence of A. baumannii strains resistant to imipenem was recorded, particularly among blood isolates. In both wards, multidrug-resistant (MDR) strains of Gram-negative bacilli were more prevalent among blood isolates than among strains cultured from other specimens. Longer stay in ICU-A promoted selection of MDR Gram-negative rods.

Detection of Clostridium difficile and its toxin A (TcdA) in stool specimens from hospitalised patients.

The study has been carried out to determine the frequency of C. difficile recovery in stool cultures and the rate of C. difficile toxin A detection in faecal specimens of patients with nosocomial diarrhoea. Clinical specimens comprised 4414 stool samples collected from 1998 to 2002 from adult patients hospitalised in different wards of a university-affiliated hospital (1200 beds) and suspected of C. difficile-associated disease (CDAD). There have been 1308 (29.6%) specimens positive for C. difficile culture (15.1% in 1998, 29.5% in 1999, 33.8% in 2000, 31.2% in 2001 and 32.0% in 2002). The highest number of C. difficile strains was cultured from stool samples of patients hospitalised in the haematology/oncology ward (51.1% of all isolates), neurology (8.3%), nephrology (8.0%), gastrointestinal surgery (7.0%) and neurosurgery (6.2%) wards. The testing for C. difficile toxin A yielded 847 (19.2%) positive samples and 3567 (80.8%) toxin A-negative results. The percentage of C. difficile toxin A-positive samples was 29.4% in 1998, 17.5% in 1999, 23.2% in 2000, 17.1% in 2001 and 15.0% in 2002. In the analysed period we observed an increase in the number of stool specimens tested for C. difficile and an increase in the number of C. difficile culture-positive samples. A decrease in the number of C. difficile toxin A-positive samples was noted in the last 2 years of the study. This phenomenon may be due to an improved antibiotic policy of the hospital.