In vitro activity of ceftolozane/tazobactam alone and in combination with amikacin against MDR/XDR Pseudomonas aeruginosa isolates from Greece.

OBJECTIVES: We evaluated the in vitro activity of ceftolozane/tazobactam and comparator agents against MDR non-MBL Pseudomonas aeruginosa isolates collected from nine Greek hospitals and we assessed the potential synergistic interaction between ceftolozane/tazobactam and amikacin. METHODS: A total of 160 non-MBL P. aeruginosa isolates collected in 2016 were tested for susceptibility to ceftolozane/tazobactam and seven comparator agents including ceftazidime/avibactam. Time-kill assays were performed for synergy testing using ceftolozane/tazobactam 60 or 7.5 mg/L, corresponding to the peak and trough concentrations of a 1.5 g q8h dose, respectively, in combination with 69 mg/L amikacin, corresponding to the free peak plasma concentration. Synergy was defined as a ≥2 log10 cfu/mL reduction compared with the most active agent. RESULTS: Overall, ceftolozane/tazobactam inhibited 64.4% of the P. aeruginosa strains at ≤4 mg/L. Colistin was the most active agent (MIC50/90, 0.5/2 mg/L; 96.3% susceptible) followed by ceftazidime/avibactam (MIC50/90, 4/16 mg/L; 80.6% susceptible). GES-type enzymes were predominantly responsible for ceftolozane/tazobactam resistance; 81.6% of the non-producers were susceptible. MICs for the P. aeruginosa isolates selected for synergy testing were 2-32 mg/L ceftolozane/tazobactam and 2-128 mg/L amikacin. The combination of ceftolozane/tazobactam with amikacin was synergistic against 85.0% of all the isolates tested and against 75.0% of the GES producers. No antagonistic interactions were observed. CONCLUSIONS: Ceftolozane/tazobactam demonstrated good in vitro activity against MDR/XDR P. aeruginosa clinical isolates, including strains with co-resistance to other antipseudomonal drugs. In combination with amikacin, a synergistic interaction at 24 h was observed against 85.0% of P. aeruginosa strains tested, including isolates with ceftolozane/tazobactam MICs of 32 mg/L or GES producers.

Genital tract infection and associated factors affect the reproductive outcome in fertile females and females undergoing in vitro fertilization.

Assisted reproductive techniques including in vitro fertilization (IVF) are being used increasingly worldwide and screening for genital tract infections (GTIs) is recommended prior to treatment as their presence may affect the success rate of IVF. The current study aimed to assess the possible associations between GTI-associated factors and reproductive outcome in a group of reproductive age fertile females and infertile females receiving IVF. A total of 111 infertile women enrolled in an IVF programme (Group A) and 104 fertile women (mothers of at least one child; Group B) underwent microbiological screening of vaginal and cervical samples. All samples were cultured using different protocols for aerobic pathogens, bacterial vaginosis (BV), Ureaplasma urealyticum, Mycoplasma hominis, Chlamydia trachomatis and human papilloma virus (HPV). Although each group were comparable in age, more infertile women were >30 years (P=0.0064), had a higher education level (P=0.0001) and were smokers (P=0.007). Only BV (P=0.0013) was more prevalent in Group A. Of the 111 infertile females who were scheduled for IVF, 32 females had a successful pregnancy (Group C) and 79 females exhibited IVF failure (Group D). Tubal factor (P=0.012), estradiol-2 (E2) levels <2,500 pg/ml (P=0.0009) and Mycoplasma infection (P=0.003) were identified to be the strongest predictors of IVF failure. The current study determined certain GTI-associated factors that may contribute to infertility in Greek females of reproductive age as well as other risk factors associated with failure in patients undergoing IVF. Further studies are required to confirm this conclusion.