Background: The aim of our study was to analyze the factors associated with the increased risk of urinary tract infection (UTI) with carbapenem-resistant (CR) Klebsiella pneumoniae (Kpn) and the antibiotic resistance spectrum of the strains in patients. As secondary objectives, we elaborated the profile of these patients and the incidence of different types of carbapenemases. Methods: We conducted a retrospective case-control study in which we compared a group of 62 patients with urinary tract infections with CR Kpn with a control group consisting of 136 patients with urinary tract infections with multidrug-resistant (MDR), but carbapenem-sensitive (CS), Kpn, who were hospitalized between 1 January 2022 and 31 March 2024. Results: Compared to patients with urinary tract infections with CS Kpn, patients with urinary tract infections with CR Kpn were preponderant in rural areas (62.9% vs. 47.1%, p = 0.038) and more frequently had an upper urinary tract infection (69.4% vs. 36.8%, p < 0.01). Among the risk factors examined, patients in the study group had a higher presence of urinary catheters inserted for up to one month (50% vs. 34.6%, p = 0.03), rate of hospitalization in the last 180 days (96.8% vs. 69.9%, p < 0.01) and incidence of antibiotic therapy in the last 180 days (100% vs. 64.7%, p < 0.01). They also had a higher rate of carbapenem treatment in the last 180 days (8.1% vs. 0%, p < 0.01). Patients in the study group had a broader spectrum of resistance to all antibiotics tested (p < 0.01), with the exception of sulfamethoxazole–trimethoprim, where the resistance rate was similar in both groups (80.6% vs. 67.6%, p = 0.059). In the multivariate analysis, transfer from other hospitals (OR = 3.51, 95% and CI: 1.430–8.629) and treatment with carbapenems in the last 180 days (OR = 11.779 and 95% CI: 1.274–108.952) were factors associated with an increased risk of disease compared to the control group. The presence of carbapenemases was observed in all patients with CR Kpn, in the order of frequency New Delhi metallo-ß-lactamase (NDM) (52.2%), Klebsiella pneumoniae carbapenemase (KPC) (32.6%), and carbapenem-hydrolyzing oxacillinase (Oxa-48) (15.2%). Conclusions: The environment of origin and previous treatment with carbapenems appear to be the factors associated with an increased risk of urinary tract infection with CR Kpn compared to patients with urinary tract infections with CS Kpn. CR Kpn exhibits a broad spectrum of antibiotic resistance, among which is resistance to carbapenem antibiotics.

Introduction: Urinary tract infections (UTIs) caused by carbapenem-resistant pathogens are increasingly common and pose serious treatment challenges due to limited antibiotic options and high complication rates. Identifying patients at risk is essential for guiding empirical therapy and improving outcomes. The primary objective of this study was to identify risk factors associated with carbapenem-resistant (CR) UTIs by comparing them with carbapenem-susceptible (CS) UTIs. Secondary objectives included analyzing the types of microorganisms involved in both groups, their antibiotic susceptibility profiles, and the presence of carbapenemase enzymes among CR UTI cases. Method: We conducted a retrospective case-control study involving 127 hospitalized patients with UTIs caused by CR microorganisms and 91 patients with UTIs caused by multidrug-resistant (MDR) strains that retain susceptibility to carbapenems, admitted between 1 October 2023, and 31 March 2025. Results: In univariate analysis, CR UTI patients had significantly higher rates of neoplasia, neurological disorders, urosepsis at admission, septic shock, the presence of urinary catheters at diagnosis, permanent nephrostomy catheters, hospitalizations within the past 180 days, previous antibiotic exposure including carbapenems, and recent urological procedures. Multivariate analysis revealed four independent risk factors for CR UTIs: neoplasia (OR = 2.152; 95% CI: 1.044–4.436; p = 0.038), neurological disorders (OR = 7.427; 95% CI: 2.804–19.674; p < 0.0001), antibiotic use in the previous 180 days (OR = 2.792; 95% CI: 1.487–5.396; p = 0.001), and prior carbapenem treatment OR = 10.313; 95% CI: 1.277–83.248; p = 0.029). Most of the isolated organisms belonged to the Enterobacterales genus, with Klebsiella spp. and Pseudomonas aeruginosa being the most common pathogens in CR UTIs, accounting for over 90% of cases. Among patients tested for carbapenemase production, all but one tested positive for at least one carbapenemase. Conclusions: Neoplasia, neurological disorders, recent antibiotic therapy, and prior carbapenem use were significantly associated with increased risk of developing CR UTIs. Klebsiella spp. and Pseudomonas aeruginosa were the predominant causative organisms, with New Delhi metallo-β-lactamase (NDM) and Klebsiella pneumoniae carbapenemase (KPC) being the most frequently identified resistance mechanisms.

Background: Pyelonephritis during pregnancy represents a significant maternal–fetal risk, particularly in the context of increasing multidrug-resistant (MDR) bacterial infections. This study aimed to characterize the microbiological profiles and antimicrobial resistance patterns of MDR pathogens causing pyelonephritis in pregnancy. Secondary objectives included the evaluation of patient characteristics, associated risk factors, and pregnancy outcomes. Methods: A retrospective comparative study was conducted including 171 pregnant patients hospitalized with acute pyelonephritis between 1 January 2017 and 30 April 2025. Thirty-four patients with MDR bacterial infections were compared with 137 patients with infections caused by pathogens with conserved antibiotic susceptibility (Non-MDR). Results: Patients with MDR pyelonephritis were significantly older than those with Non-MDR infections (mean age 27.76 vs. 25.30 years, p = 0.03). MDR infections were more frequently diagnosed in the third trimester of pregnancy (58.8% vs. 29.9%, p = 0.003) and affected multiparous women more often (44.1% vs. 19.7%, p = 0.006). No statistically significant differences were observed between groups regarding clinical presentation or laboratory parameters (p > 0.05). Prior antibiotic exposure was significantly more common in the MDR group (85.29% vs. 26.61%, p < 0.001), as was a history of urological procedures, including urinary catheterization (29.41% vs. 15.10%, p = 0.009). For multivariate analysis, two factors were predictive for pyelonephritis with MDR pathogens: previous antibiotic treatment—OR 20.37 (95% CI 2.19–189.88) and urological procedures—OR 13.23 (95% CI 2.24-78-22). Escherichia coli was the predominant pathogen in both groups but was isolated more frequently in the Non-MDR cohort (81.75% vs. 58.82%, p = 0.015), followed by Klebsiella pneumoniae, which appeared more frequently in the study group (23.53% vs. 10.22%, p = 0.011). MDR isolates demonstrated significantly higher resistance rates to all tested antibiotics (p < 0.05). Complete resistance to ampicillin was observed in the MDR group (100%), compared with 58.01% in the Non-MDR group, indicating markedly reduced efficacy of this agent. Adverse neonatal outcomes were more frequent in the MDR group, with higher rates of Apgar scores < 7 at admission (23.5% vs. 8.8%, p = 0.01) and increased neonatal intensive care unit admission (20.6% vs. 7.3%, p = 0.02). For multivariate analysis, pyelonephritis with MDR pathogens was predictive for Neonatal Intensive Care Unit (NICU) admission (OR 8.17, 95% CI 2.41–27.67). Conclusions: These findings highlight the need for the periodic revision of empirical antibiotic protocols and risk-adapted therapeutic strategies in pregnant patients in order to reduce maternal and fetal morbidity.

Introduction: Upper urinary tract infections (UUTIs) are among the most common serious infections during pregnancy and may be associated with maternal and fetal complications. The increasing prevalence of multidrug-resistant pathogens has led to the use of broader-spectrum antibiotics, including meropenem. However, data regarding the safety and efficacy of meropenem in pregnant women remain limited. The aim of this study was to evaluate the indications, efficacy, and safety of meropenem treatment in pregnant women with UUTIs and its impact on maternal and fetal outcomes. Methods: We conducted a retrospective study over a 12-year period including pregnant women hospitalized with UUTIs who received meropenem. The control group consisted of pregnant women with UUTIs who were treated with ceftriaxone during the same period. Results: Pregnant women treated with meropenem were more frequently diagnosed in the third trimester of pregnancy (p = 0.01) and were more often multiparous (p = 0.006). Sepsis and septic shock occurred significantly more frequently in the study group (p < 0.01), and multivariate analysis identified them as the main indications for meropenem administration (OR 10.54, 95% CI 3.30–33.70 for sepsis; OR 3.28, 95% CI 1.01–10.62 for septic shock). Patients in the study group had a higher rate of transfer to the obstetrics clinic (p = 0.032), a longer duration of antibiotic therapy (p = 0.031), and a longer hospital stay (p < 0.01). No maternal deaths were reported in either group. The rate of adverse pregnancy outcomes was similar between the two groups, except for the Apgar score, which was lower in the meropenem group (p = 0.007). Escherichia coli and Klebsiella pneumoniae were the most frequently isolated pathogens in both groups. Conclusions: Meropenem therapy in pregnant women with UUTIs was mainly indicated in cases of sepsis and septic shock and was associated with favorable maternal clinical evolution, even in patients with severe infections. The rate of adverse pregnancy outcomes was similar between the two groups, although a lower Apgar score was observed in the meropenem group; the severity of illness in the meropenem group should be considered when interpreting the lower Apgar scores. Further prospective multicenter studies are needed to better evaluate the safety and clinical effectiveness of meropenem during pregnancy.