Effects of pH on the Pathogenicity of Escherichia coli and Klebsiella pneumoniae on the Kidney: In Vitro and In Vivo Studies.

Urine pH reflects the functional integrity of the body and may influence the virulence of uropathogenic Escherichia coli and Klebsiella pneumoniae, the main causes of urinary tract infections (UTIs). This study evaluated the effects of acidic pH on the pathogenicity of uropathogenic E. coli and K. pneumoniae strains, in vitro and in vivo. Four uropathogenic E. coli and four K. pneumoniae strains were used. Biofilm formation, growth competition indices, motility, and adhesion and invasion of human renal cells were analyzed in media with acidic, neutral, and alkaline pH. A murine lower UTI model was used, with urine adjusted to acidic, neutral, or alkaline pH. At acidic pH, E. coli and K. pneumoniae exhibited higher bacterial concentrations in the kidneys and systemic symptoms, including bacteremia. Alkaline urine pH did not affect bacterial concentrations of any strain. In mice with UTIs caused by E. coli Nu14 and K. pneumoniae HUVR42 and acidic urine pH, histopathological studies of the kidneys showed acute inflammation affecting the urothelium and renal parenchyma, which are traits of acute pyelonephritis. These results indicate that acidic pH could increase the pathogenicity of E. coli and K. pneumoniae in murine models of lower UTI, promoting renal infection and acute inflammation.

Increased water intake dilutes protective uromodulin levels in urine and results in increased rates of pyelonephritis in a murine model.

AIM: Urinary tract infections (UTIs) rank among the most prevalent infections in humans, carrying substantial implications for public health. Women experiencing recurrent UTIs are often advised to boost their fluid intake to help eliminate bacteria. In this study, we explored the impact of elevated fluid consumption during UTIs using a mouse model of pyelonephritis. METHODS: UTI was induced in 8-10 w female BALB/cJ-mice by surgically injecting Escherichia coli (O6:K13:H1) into the bladder whereafter mice were randomized to gel food (GF) or regular chow. Immune response and infection severity were determined 24-h post-infection. In vitro bacterial growth (OD600) was determined in urine from mice or from human volunteers. RESULTS: Gel feeding increased urine output (1.40 ± 0.77 µL min-1, p < 0.01) and diluted the urine (668.7 ± 177 mOsmol kg-1, p < 0.0001) compared to controls on regular chow (urine output: 0.34 ± 0.27 µL min-1, osmolality: 1439 ± 473.5 mOsmol kg-1). Mice on GF had a higher risk of pyelonephritis (87.5%) and more severe infections (26.22 ± 9.88 CFU mg-1 tissue) compared to controls (43.75%; 3.87 ± 3.56 CFU mg-1, p < 0.01). Correspondingly, the growth of E. coli was markedly reduced at osmolalities above 1200 mOsmol kg-1 compared to 600 mOsmol kg-1 and GF mice had lower urine levels of uromodulin (13.70 ± 1.89 µg mL-1, p < 0.01) compared to controls (24.65 ± 2.70 µg mL-1). CONCLUSION: Increased water intake and urine flow in mice will markedly increase the risk of pyelonephritis. The increased risk may reflect reduced urine uromodulin combined with optimized growth conditions for E. coli. The study does not immediately support the notion that established UTIs can be eliminated by increased water intake.

Identification and characterization of a novel α-haemolytic streptococci, Streptococcus parapneumoniae sp. nov., which caused bacteremia with pyelonephritis.

OBJECTIVES: We report a case of bacteremia with pyelonephritis in an adult male with an underlying disease caused by α-hemolytic streptococci. α-Hemolytic streptococci were isolated from blood, but it was challenging to identify its species. This study aimed to characterize the causative bacterium SP4011 and to elucidate its species. METHODS: The whole-genome sequence and biochemical characteristics of SP4011 were determined. Based on the genome sequence, phylogenetic analysis was performed with standard strains of each species of α-hemolytic streptococci. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were calculated. RESULTS: SP4011 showed optochin susceptibility and bile solubility, but did not react with pneumococcal omni antiserum. Phylogenetic analysis of the whole-genome sequence showed that SP4011 clustered with S. pneumoniae and S. pseodopneumoniae and was most closely related to S. pseodopneumoniae. Genomic analysis revealed that ANI and dDDH values between SP4011 and S. pseodopneumoniae were 94.0 % and 56.0 %, respectively, and between SP4011 and S. pneumoniae were 93.3 % and 52.2 %, respectively. Biochemical characteristics also showed differences between SP4011 and S. pseodopneumoniae and between SP4011 and S. pneumoniae. These results indicate that SP4011 is a novel species. CONCLUSION: Our findings indicate that SP4011 is a novel species of the genus Streptococcus. SP4011 has biochemical characteristics similar to S. pneumoniae, making it challenging to differentiate and requiring careful clinical diagnosis. This isolate was proposed to be a novel species, Streptococcus parapneumoniae sp. nov. The strain type is SP4011T (= JCM 36068T = KCTC 21228T).

Use of Fever Duration to Guide Management of Urinary Tract Infection.

BACKGROUND: The appropriate duration of antimicrobial therapy for febrile urinary tract infection (fUTI) in children has not been established. This study examined the optimal duration of treatment for fUTI in children. METHODS: We created a protocol that used fever duration to determine the duration of antibiotic administration. Transvenous antibiotics were administered until 3 days after resolution of fever, followed by oral antibiotics for 1 week. Diagnosis of fUTI was based on a fever of 37.5°C or higher and a quantitative culture of catheterized urine yielded a bacteria count of ≥5 × 104. Acute focal bacterial nephritis (AFBN) and pyelonephritis (PN) were diagnosed on the basis of contrast-enhanced computed tomography (eCT) findings. We retrospectively reviewed treatment outcomes. RESULTS: Of the 78 patients treated according to our protocol, data from 58 were analyzed-49 children (30 boys) had PN and nine (three boys) had AFBN. Blood test results showed that patients with AFBN had significantly higher white blood cell counts and C-reactive protein levels than did those with PN; however, urinary findings and causative bacteria did not differ between groups. Time to resolution of fever and duration of intravenous antibiotic administration were significantly longer in patients with AFBN than in those with PN. However, average duration of AFBN treatment was 14.2 days, which was shorter than the previously reported administration period of 3 weeks. No recurrence was observed in AFBN patients. CONCLUSIONS: A protocol that used fever duration to determine the duration of antimicrobial treatment was useful. Invasive examinations, such as eCT, were not required.

Cefepime-taniborbactam and CERTAIN-1: Can we treat carbapenem-resistant infections?

Wagenlehner and colleagues1 demonstrated non-inferiority and superiority with respect to a primary endpoint of composite success (microbiological plus clinical) of cefepime/taniborbactam vs. meropenem in treating complicated urinary tract infections and acute pyelonephritis caused by carbapenem-susceptible gram-negative bacteria in adults. A major area of interest in real-world application of cefepime/taniborbactam is its potential role in treating carbapenem-resistant infections, which deserves further investigation.

Clinicopathologic Spectrum and Outcomes of Infections Diagnosed on Graft Biopsies and Nephrectomy in Live Renal Allograft Recipients: An Institutional Experience.

OBJECTIVES: Modern immunosuppressive regimens have reduced rejection episodes in renal allograft recipients but have increased the risk of opportunistic infections. Infections are considered to be the second leading cause of death after cardiovascular complications in renal allograft recipients. Data on opportunistic infections affecting the allograft itself are scarce. The present study describes the spectrum of renal opportunistic infections and their outcomes diagnosed on renal allograft biopsies and nephrectomy specimens. MATERIALS AND METHODS: Our retrospective observational study was conducted from December 2011 to December 2021. We analyzed infectious episodes diagnosed on renal allograft biopsies or graft nephrectomy specimens. We obtained clinical, epidemiological, and laboratory details for analyses from hospital records. RESULTS: BK virus nephropathy was the most common opportunistic infection affecting the allograft, accounting for 47% of cases, followed by bacterial graft pyelonephritis (25%). Mucormycosis was the most common fungal infection. The diagnosis of infection from day of transplant ranged from 14 days to 39 months. Follow-up periods ranged from 1 to 10 years. Mortality was highest among patients with opportunistic fungal infection (62%), followed by viral infections, and graft failure rate was highest in patients with graft pyelonephritis (50%). Among patients with BK polyomavirus nephropathy, 45% had stable graft function compared with just 33% of patients with bacterial graft pyelonephritis. CONCLUSIONS: BK polyoma virus infection was the most common infection affecting the renal allograft in our study. Although fungal infections caused the highest mortality among our patients, bacterial graft pyelonephritis was responsible for maximum graft failure. Correctly identifying infections on histology is important so that graft and patient life can be prolonged.

Cefepime/Enmetazobactam: First Approval.

Cefepime/enmetazobactam (EXBLIFEP®), an intravenous (IV) antibacterial fixed-dose combination of a 4th generation cephalosporin and an extended-spectrum ß-lactamase (ESBL) inhibitor, is being developed by Allecra Therapeutics and ADVANZ PHARMA for the treatment of infections caused by multi-drug-resistant (MDR) Gram-negative bacteria. In February 2024, cefepime/enmetazobactam was approved in the USA for use in adults with complicated urinary tract infections (cUTI) including pyelonephritis, caused by susceptible strains of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Enterobacter cloacae complex. In March 2024, cefepime/enmetazobactam was approved in the EU for use in adults for the treatment of cUTI, including pyelonephritis, and hospital-acquired pneumonia, including ventilator associated pneumonia, and the treatment of patients with bacteraemia occurring in association with or suspected to be associated with any of these infections. This article summarizes the milestones in the development of cefepime/enmetazobactam leading to this first approval for the treatment of adults with infections caused by MDR Gram-negative bacteria.

Regulation of renal aquaporin water channels in acute pyelonephritis.

Acute pyelonephritis (APN) is most frequently caused by uropathogenic Escherichia coli (UPEC), which ascends from the bladder to the kidneys during a urinary tract infection. Patients with APN have been reported to have reduced renal concentration capacity under challenged conditions, polyuria, and increased aquaporin-2 (AQP2) excretion in the urine. We have recently shown increased AQP2 accumulation in the plasma membrane in cell cultures exposed to E. coli lysates and in the apical plasma membrane of inner medullary collecting ducts in a 5-day APN mouse model. This study aimed to investigate if AQP2 expression in host cells increases UPEC infection efficiency and to identify specific bacterial components that mediate AQP2 plasma membrane insertion. As the transepithelial water permeability in the collecting duct is codetermined by AQP3 and AQP4, we also investigated whether AQP3 and AQP4 localization is altered in the APN mouse model. We show that AQP2 expression does not increase UPEC infection efficiency and that AQP2 was targeted to the plasma membrane in AQP2-expressing cells in response to the two pathogen-associated molecular patterns (PAMPs), lipopolysaccharide and peptidoglycan. In contrast to AQP2, the subcellular localizations of AQP1, AQP3, and AQP4 were unaffected both in lysate-incubated cell cultures and in the APN mouse model. Our finding demonstrated that cellular exposure to lipopolysaccharide and peptidoglycan can trigger the insertion of AQP2 in the plasma membrane revealing a new regulatory pathway for AQP2 plasma membrane translocation, which may potentially be exploited in intervention strategies.NEW & NOTEWORTHY Acute pyelonephritis (APN) is associated with reduced renal concentration capacity and increased aquaporin-2 (AQP2) excretion. Uropathogenic Escherichia coli (UPEC) mediates changes in the subcellular localization of AQP2 and we show that in vitro, these changes could be elicited by two pathogen-associated molecular patterns (PAMPs), namely, lipopolysaccharide and peptidoglycan. UPEC infection was unaltered by AQP2 expression and the other renal AQPs (AQP1, AQP3, and AQP4) were unaltered in APN.

Empirical antimicrobial prescribing for pyelonephritis in patients discharged from 15 US Emergency Departments: an opportunity for improvement.

BACKGROUND: Urinary tract infections (UTIs) are commonly treated in the emergency department (ED), and unfortunately, resistance to first-line agents is increasing. OBJECTIVES: To characterize treatment of pyelonephritis in a nationally representative sample of ED patients and to identify patient- and treatment-specific factors associated with receiving initial inactive antibiotics. METHODS: We conducted a multicentre, observational cohort study utilizing the Emergency Medicine PHARMacotherapy Research NETwork (EMPHARM-NET), comprising 15 geographically diverse US EDs. All patients ≥18 years of age with a diagnosis of pyelonephritis between 2018 and 2020 were included. The primary endpoint was the proportion of patients who received initial inactive empirical antibiotic therapy and to identify predictive factors of inactive antibiotic therapy. RESULTS: Of the 3714 patients evaluated, 223 had culture-positive pyelonephritis. Median patient age was 50.1 years and patients were mostly female (78.3%). Overall, 40.4% of patients received an IV antibiotic, most commonly ceftriaxone (86.7%). The most frequently prescribed antibiotics were cefalexin (31.8%), ciprofloxacin (14.3%), cefdinir (13.5%) and trimethoprim/sulfamethoxazole (12.6%). Overall, 10.3% of patients received initial inactive therapy. After adjustment in a multivariable analysis, long-acting IV antibiotic was predictive of inactive therapy (OR 0.23, 95% CI 0.07-0.83). CONCLUSIONS: In our prospective, multicentre observational study, we found that only 40.4% of patients with pyelonephritis received empirical IV antibiotics in the ED, contributing to inactive therapy. Receipt of long-acting IV antibiotics was independently associated with a decreased rate of initial inactive therapy. This reinforces guideline recommendations to administer long-acting IV antibiotics empirically in the ED upon suspicion of pyelonephritis.

Cefepime-Taniborbactam in Complicated Urinary Tract Infection.

BACKGROUND: Carbapenem-resistant Enterobacterales species and multidrug-resistant Pseudomonas aeruginosa are global health threats. Cefepime-taniborbactam is an investigational ß-lactam and ß-lactamase inhibitor combination with activity against Enterobacterales species and P. aeruginosa expressing serine and metallo-ß-lactamases. METHODS: In this phase 3, double-blind, randomized trial, we assigned hospitalized adults with complicated urinary tract infection (UTI), including acute pyelonephritis, in a 2:1 ratio to receive intravenous cefepime-taniborbactam (2.5 g) or meropenem (1 g) every 8 hours for 7 days; this duration could be extended up to 14 days in case of bacteremia. The primary outcome was both microbiologic and clinical success (composite success) on trial days 19 to 23 in the microbiologic intention-to-treat (microITT) population (patients who had a qualifying gram-negative pathogen against which both study drugs were active). A prespecified superiority analysis of the primary outcome was performed after confirmation of noninferiority. RESULTS: Of the 661 patients who underwent randomization, 436 (66.0%) were included in the microITT population. The mean age of the patients was 56.2 years, and 38.1% were 65 years of age or older. In the microITT population, 57.8% of the patients had complicated UTI, 42.2% had acute pyelonephritis, and 13.1% had bacteremia. Composite success occurred in 207 of 293 patients (70.6%) in the cefepime-taniborbactam group and in 83 of 143 patients (58.0%) in the meropenem group. Cefepime-taniborbactam was superior to meropenem regarding the primary outcome (treatment difference, 12.6 percentage points; 95% confidence interval, 3.1 to 22.2; P = 0.009). Differences in treatment response were sustained at late follow-up (trial days 28 to 35), when cefepime-taniborbactam had higher composite success and clinical success. Adverse events occurred in 35.5% and 29.0% of patients in the cefepime-taniborbactam group and the meropenem group, respectively, with headache, diarrhea, constipation, hypertension, and nausea the most frequently reported; the frequency of serious adverse events was similar in the two groups. CONCLUSIONS: Cefepime-taniborbactam was superior to meropenem for the treatment of complicated UTI that included acute pyelonephritis, with a safety profile similar to that of meropenem. (Funded by Venatorx Pharmaceuticals and others; CERTAIN-1 ClinicalTrials.gov number, NCT03840148.).

Androgen exposure impairs neutrophil maturation and function within the infected kidney.

Urinary tract infections (UTIs) in men are uncommon yet carry an increased risk for severe pyelonephritis and other complications. In models of Escherichia coli UTI, C3H/HeN mice develop high-titer pyelonephritis (most with renal abscesses) in a testosterone-dependent manner, but the mechanisms underlying this phenotype are unknown. Here, using female mouse models, we show that androgen exposure impairs neutrophil maturation in the upper and lower urinary tract, compounded by a reduction of neutrophil function within the infected kidney, enabling persistent high-titer infection and promoting abscess formation. Following intravesical inoculation with uropathogenic E. coli (UPEC), kidneys of androgen-exposed C3H mice showed delayed local pro-inflammatory cytokine responses while robustly recruiting neutrophils. These were enriched for an end-organ-specific population of aged but immature neutrophils (CD49d+, CD101-). Compared to their mature counterparts, these aged immature kidney neutrophils exhibited reduced function in vitro, including impaired degranulation and diminished phagocytic activity, while splenic, bone marrow, and bladder neutrophils did not display these alterations. Furthermore, aged immature neutrophils manifested little phagocytic activity within intratubular UPEC communities in vivo. Experiments with B6 conditional androgen receptor (AR)-deficient mice indicated rescue of the maturation defect when AR was deleted in myeloid cells. We conclude that the recognized enhancement of UTI severity by androgens is attributable, at least in part, to local impairment of neutrophil maturation in the urinary tract (largely via cell-intrinsic AR signaling) and a kidney-specific reduction in neutrophil antimicrobial capacity.IMPORTANCEAlthough urinary tract infections (UTIs) predominantly occur in women, male UTIs carry an increased risk of morbidity and mortality. Pyelonephritis in androgen-exposed mice features robust neutrophil recruitment and abscess formation, while bacterial load remains consistently high. Here, we demonstrate that during UTI, neutrophils infiltrating the urinary tract of androgen-exposed mice exhibit reduced maturation, and those that have infiltrated the kidney have reduced phagocytic and degranulation functions, limiting their ability to effectively control infection. This work helps to elucidate mechanisms by which androgens enhance UTI susceptibility and severity, illuminating why male patients may be predisposed to severe outcomes of pyelonephritis.

Clinical and microbiological characteristics of female patients with acute pyelonephritis who experienced urinary tract infections within the previous year.

BACKGROUND: This study aimed to examine the clinical and microbiological characteristics of female patients with recurrent acute pyelonephritis (APN). METHODS: A retrospective cohort study was conducted at a tertiary care hospital in South Korea from July 2019 to December 2021. All female patients aged ≥ 19 years who were diagnosed with community-acquired APN on admission were enrolled. The recurrent group included patients with APN who experienced urinary tract infections within the previous year. The clinical characteristics, types of causative organisms, major antibiotic resistance, and molecular characteristics of Escherichia coli strains were compared between the recurrent and non-recurrent groups. RESULTS: A total of 285 patients with APN were analyzed, including 41 (14.4%) in the recurrent group. Compared to the non-recurrent group, the recurrent group had a higher Charlson Comorbidity Index (1.8 ± 2.1 vs. 1.1 ± 1.5; P = 0.01) and a higher proportion of bladder abnormalities, such as neurogenic bladder (12.2% vs. 2.0%; P = 0.001) and urinary catheterization (12.2% vs. 1.6%; P < 0.001). Escherichia coli was the most common causative organism in both groups. The proportion of Klebsiella pneumoniae (17.1% vs. 4.7%; P = 0.007) and Pseudomonas aeruginosa (5.7% vs. 0.5%; P = 0.014) as a causative organism was higher in the recurrent group. Regarding the microbiological characteristics of Escherichia coli, there were no significant differences in the proportion of antibiotic resistance, phylogenetic groups, resistance genes, and virulence factors between the two groups. Multivariable analysis showed that neurogenic bladder and a history of admission or antibiotic use during 1 year prior to inclusion were significantly associated with recurrent APN. CONCLUSIONS: The proportion of causative organisms except Escherichia coli was higher in the recurrent group than in the non-recurrent group. Neurogenic bladder and a history of admission or antibiotic use during 1 year prior to inclusion were risk factors for recurrent APN.

[EFFECT OF ETHNICITY ON BACTERIAL RESISTANCE AND OBSTETRICAL OUTCOMES AMONG PREGNANT WOMEN ADMITTED TO MATERNAL-FETAL MEDICINE UNIT WITH THE DIAGNOSIS OF PYELONEPHRITIS DURING 2017-2020].

INTRODUCTION: Antibiotic resistance is a worldwide concern. No study has ever examined the correlation between ethnicity and antibiotic resistance. We examined those parameters among hospitalized pregnant patients diagnosed with pyelonephritis. AIMS: Should ethnic origin play a role in optimizing antibiotic therapy? To better comprehend, we have chosen a cohort of hospitalized pregnant patients with a pyelonephritis diagnosis. METHODS: A total of 105 cases of patients hospitalized in the Shamir Medical Center between the years 2017-2020 were analysed. Feto-maternal outcomes and antibiotic resistance in relation to ethnicity were plotted statistically using chi-square tests (Arab, 40%; North Africa, 13%; Europe-Ashkenaz,10%; Ethiopia/Iran/Kavkaz/Iraq/other, 3%; Turkey/Uzbekistan/Yemen 2%). RESULTS: Ethnic groups included Arab (40%), others referred as "None-Arab". The antibiotic resistance panel revealed differences comparing the two largest groups (Arab% VS non-Arab%), whereas there was no correlation between any ethnic group and obstetrics parameter. Arab women were more resistant to ciprofloxacin (33% vs 7%, P= 0.026) and less sensitive to imipenem (60% vs 90.9%, P= 0.03); less sensitive to ceftriaxone and cefuroxime. CONCLUSIONS: There was a correlation between ethnic origin of pregnant patients diagnosed with pyelonephritis and antibiotic resistance. We hope ethnicity, might, in some cases, assist physicians choosing the optimal therapy.

Poor performance status is a risk factor for higher detection of Gram positive coccus in stone-related pyelonephritis.

INTRODUCTION: We aimed to investigate the detection rate of causative organisms in stone-related pyelonephritis and to compare their distribution according to patient backgrounds. METHODS: We retrospectively identified patients with stone-related pyelonephritis. Clinical data were collected between November 2012 and August 2020 at Wakayama Medical University Hospital, including on patient backgrounds and causative organisms. Patients were categorized by Eastern Cooperative Oncology Group performance status (PS) as the good PS group (0, 1) and the poor PS group (2-4). Bacteria were divided into Gram-positive cocci (GPC) or non-GPC groups and logistic regression analysis was used to examine factors that predict detection of GPC. RESULTS: Seventy-nine patients had stone-related pyelonephritis, 54 (68.4 %) in the good PS group and 25 (31.6 %) in the poor PS group. In the good PS group, Escherichia coli (67 %) was followed by Klebsiella species (9 %), while in the poor PS group, Escherichia coli (20 %) was followed by Enterococci and Staphylococci (12 %). GPC detection rate was significantly higher in the poor PS group than in the good PS group (40.0 % vs 14.8 %, p = 0.016), and multivariate logistic regression analysis showed that poor PS was an independent factor predicting detection of GPC (OR = 6.54, p = 0.02). CONCLUSIONS: The distribution of the causative organisms in stone pyelonephritis was similar to that in common complicated urinary tract infections. Poor PS may be an independent predictor of GPC detection in patients with stone pyelonephritis.

[Development of purulent-destructive forms of acute pyelonephritis in patients with a history of new coronavirus infection Covid-19].

INTRODUCTION: Since 2019, more than 600 million cases of the new coronavirus infection Covid-19 have been reported worldwide. According to various studies, the development of a systemic inflammatory response and "cytokine storm" play an important role in the pathogenesis of kidney damage, which leads to impaired microcirculation, increased thrombus formation and the development of ischemic areas in the parenchyma. AIM: To study the frequency and possible causes of purulent forms of pyelonephritis in patients who have had a new coronavirus infection Covid-19. MATERIALS AND METHODS: The prospective and retrospective study included the results of 403 patients with acute non-obstructive pyelonephritis in the pre-Covid period and those with a history of a new coronavirus infection. RESULTS: In patients with acute non-obstructive pyelonephritis without past urological history who had a new coronavirus infection, an increase in purulent-destructive forms from 5.0 to 17.0% was noted. One of the reasons is increased antibiotic resistance and the emergence of pan-resistant uropathogens due to irrational use of antibacterial drugs. CONCLUSION: The use of reserve antibacterial drugs in patients with acute pyelonephritis as empirical therapy and anticoagulants in order to improve microcirculation and prevent thrombosis is pathogenetically justified.

Pyelonephritis in pregnancy: clinical and laboratorial aspects and perinatal results / Pielonefrite na gestação: aspectos clínicos e laboratoriais e resultados perinatais

Abstract Objective To identify the prevalence of pyelonephritis during pregnancy and to analyze the clinical and laboratorial aspects, perinatal results and complications. Methods A transversal study of 203 pregnant women who had pyelonephritis during pregnancy and whose labor took place between 2010 and 2016 at a hospital in the state of Santa Catarina, Brazil. The analysis was based on medical records as well as on the hospital's database. Clinical and laboratory conditions, antibiotics, bacterial resistance, perinatal outcomes and complications were all taken into account. The data was compared using the Mann-Whitney test and the Chi-square test. Results A prevalence of 1.97% with pyelonephritis was evidenced, with most patients having it during the second trimester of gestation. The bacteriamost commonly found in the urine cultures was Escherichia coli, in 76.6% of cases, followed by Klebsiella pneumoniae (8.7%). Ceftriaxone had the lowest bacterial resistance (only 3.5% of the cases). On the other hand, ampicillin and cephalothin presented higher bacterial resistance, 52% and 36.2%, respectively. The risk of very premature delivery was more than 50% higher in patients with pyelonephritis. Conclusion Ampicillin and first-generation cephalosporins are associated with a higher bacterial resistance while ceftriaxone proved to have a high efficacy for the treatment of pyelonephritis due to low bacterial resistance. Patients with pyelonephritis showed a higher risk for very premature delivery (< 32 weeks). In this casuistry, there were no others significant differences in the overall perinatal outcomes when compared with the routine service series.

Resumo Objetivo Identificar a prevalência da pielonefrite durante a gestação, analisar seus aspectos clínicos e laboratoriais, resultados perinatais e complicações. Métodos Estudo transversal que incluiu 203 gestantes com pielonefrite durante a gestação e cujos partos aconteceram entre 2010 e 2016 em um hospital no estado de Santa Catarina, no Brasil. A análise foi feita através de informações coletadas de prontuários e da base de dados do hospital. Foram levados em consideração aspectos received Resultados Foi evidenciada uma prevalência de 1,97%, sendo que a maioria das pacientes se encontrava no segundo trimestre de gestação. A bactériamais encontrada nas uroculturas foi a Escherichia coli, em 76,6% dos casos, seguido pela Klebsiella pneumoniae (8,7%). A ceftriaxona, usada como primeira escolha, demonstrou ser o antibiótico commenor resistência bacteriana (apenas 3,5% dos casos). A ampicilina e a cefalotina apresentaram maiores resistências bacterianas, 52% e 36,2%, respectivamente. O risco de parto prematuro extremo (<32 semanas) foimais que 50% maior em pacientes com pielonefrite. Conclusão A ampicilina e cefalosporinas de primeira geração estão associadas à maior resistência bacteriana enquanto a ceftriaxona provou ter uma alta eficácia para o tratamento da pielonefrite devido à baixa resistência bacteriana. Pacientes com pielonefrite têm maior risco para parto prematuro extremo (< 32 semanas). Nesta casuística, não houveram outras diferenças significativas nos resultados perinatais gerais quando comparados com a série de serviços de rotina.

Pharmacodynamic profiling of commonly prescribed antimicrobial drugs against Escherichia coli isolates from urinary tract

Since antimicrobial resistance among uropathogens against current first line agents has affected the management of severe urinary tract infection, we determined the likelihood that antibiotic regimens achieve bactericidal pharmacodynamic exposures using Monte Carlo simulation for five antimicrobials (ciprofloxacin, ceftriaxone, piperacillin/tazobactam, ertapenem, and meropenem) commonly prescribed as initial empirical treatment of inpatients with severe community acquired urinary tract infections. Minimum inhibitory concentration determination by Etest was performed for 205 Brazilian community urinary tract infection Escherichia coli strains from 2008 to 2012 and 74 E. coli bloodstream strains recovered from a surveillance study. Pharmacodynamic exposure was modeled via a 5000 subject Monte Carlo simulation. All isolates were susceptible to ertapenem and meropenem. Piperacillin/tazobactam, ceftriaxone and ciprofloxacin showed 100%, 97.5% and 83.3% susceptibility among outpatient isolates and 98.6%, 75.7% and 64.3% among inpatient isolates, respectively. Against outpatient isolates, all drugs except ciprofloxacin (82.7% in aggressive and 77.6% in conservative scenarios) achieved high cumulative fraction of response: car-bapenems and piperacillin/tazobactam cumulative fraction of responses were close to 100%, and ceftriaxone cumulative fraction of response was 97.5%. Similar results were observed against inpatients isolates for carbapenems (100%) and piperacillin/tazobactam (98.4%), whereas ceftriaxone achieved only 76.9% bactericidal cumulative fraction of response and ciprofloxacin 61.9% (aggressive scenario) and 56.7% (conservative scenario) respectively. Based on this model, standard doses of beta-lactams were predicted to deliver sufficient pharmacodynamic exposure for outpatients. However, ceftriaxone should be avoided for inpatients and ciprofloxacin empirical prescription should be avoided in both inpatients and outpatients with complicated urinary tract infection.

Resultados de dois esquemas de tratamento da pielonefrite durante a gravidez e correlação com o desfecho da gestação / Results of two treatment regimens for pyelonephritis during pregnancy and correlation with pregnancy outcome

OBJETIVO: Determinar o perfil epidemiológico das gestantes internadas por infecção do trato urinário, bem como verificar os agentes mais prevalentes e a resposta à antibioticoterapia. MÉTODOS: Estudo retrospectivo, que incluiu 106 gestantes internadas para tratamento de infecção do trato urinário no período entre janeiro de 2007 a dezembro de 2010. A avaliação constituiu-se de análise de prontuários dessas gestantes, observando-se informações sobre a internação e a gestação, bem como seu desfecho. Foi realizada a análise estatística por meio do programa Statistical Package for the Social Science, versão 15.0. Foram utilizados, para análise dos dados, o teste bilateral exato de Fisher e o teste t de Student, bem como métodos de estatística descritiva. RESULTADOS: Uroculturas positivas foram encontradas em 60,5% das gestantes internadas por infecção do trato urinário. O agente infeccioso mais frequente foi Escherichia coli e não houve diferença quanto à resistência, à recorrência ou a complicações entre os agentes etiológicos mais frequentes. Gestantes com infecção do trato urinário prévia tiveram maior risco de recorrência (OR=10,8; p<0,05). Os antibióticos mais frequentemente utilizados na internação foram ampicilina e cefazolina. Troca de esquema terapêutico por resistência bacteriana ocorreu em 11,9% das pacientes que usaram cefazolina e em 20% das que usaram ampicilina (OR=5,5; p<0,05). O índice de complicações gestacionais foi igual nos dois tratamentos. Não houve diferença entre as médias do número de dias de internação para os dois tratamentos. CONCLUSÃO: A ampicilina esteve associada a maior índice de resistência bacteriana que a cefazolina, necessitando de maior número de trocas do esquema terapêutico, sem resultar em diferença nos desfechos clínicos e tempo de internação.

PURPOSE: To determine the epidemiological profile of women admitted for urinary tract infection as well as to verify the most prevalent agents and response to antibiotic therapy. METHODS: A retrospective study of 106 pregnant women admitted to a university hospital for urinary tract infection treatment during the period between January 2007 to December 2010. The evaluation was based on analysis of the medical records of these pregnant women, with the observation of hospitalization and pregnancy data, as well as its outcome. Statistical analysis was performed using Statistical Package for the Social Science, version 15.0. The bilateral Fisher exact test and Student's t test were used for data analysis, as well as descriptive statistical methods. RESULTS: Positive urine cultures were observed in 60.5% of pregnant women admitted due to urinary tract infection. The most frequent infectious agent was Escherichia coli and no difference in resistance, recurrence or complications was observed between the most frequent etiologic agents. Pregnant women with previous UTI had a higher recurrence risk (OR=10.8; p<0.05). The antibiotics most commonly used during hospitalization were ampicillin and cefazolin. Change of therapeutic agent due to bacterial resistance occurred in 11.9% of patients who took cefazolin and in 20% of patients who took ampicillin (OR=5.5; p<0.05). The rate of gestational complications was the same for both treatments. There was no difference in mean number of days of hospitalization between the treatments. CONCLUSION: In the studied population ampicillin showed a higher rate of bacterial resistance than cefazolin, requiring a larger number of treatment regimen exchanges, without resulting in differences in clinical outcome or time of hospitalization.

Pielonefritis aguda en el embarazo y susceptibilidad antimicrobiana de uropatógenos: comparación de dos décadas / Acute pyelonephritis in pregnancy and antimicrobial susceptibility of uropathogens: comparison of two decades

ANTECEDENTES: La infección de tracto urinario (ITU) es la patología infecciosa bacteriana más frecuente del embarazo. Los esfuerzos por lograr una detección precoz y tratamiento adecuado se basan en la toma sistemática de urocultivo al inicio del embarazo, estudiando los agentes causales y la sensibilidad de éstos a los antibióticos recomendados durante la gestación. OBJETIVO: Describir los cuadros clínicos y microbio-lógicos de los casos de ITU registrados en embarazadas atendidas en nuestra institución durante el año 2007 y compararlos con los reportes de 1988 y 2001. MÉTODOS: Se revisaron las historias clínicas de 112 embarazadas que cursaron ITU durante 2007, determinando la frecuencia de pielonefritis aguda (PNA), agente infeccioso y susceptibilidad a los antimicrobianos. Se compararon estos datos con los registrados en 2001 y 1988 mediante el cálculo de Odds Ratios. RESULTADOS: La proporción de PNA mostró una tendencia decreciente entre 1988, 2001 y 2007 (p<0,001). Escherichia coli fue el agente infeccioso más frecuente, sin embargo, su frecuencia disminuyó entre 2001 y 2007 (OR 0,32; IC95% 0,17-0,58). Se observó un aumento de ITU por Streptococcus agalactiae (SGB) (OR 3,98; 1,85-8,67) durante igual período. La sensibilidad antimicrobiana a ampicilina, gentamicina, nitrofurantoina y cotrimoxazol no presentó diferencias significativas entre 2001-2007. CONCLUSIÓN: Se documentó un cambio en el perfil clínico y microbiológico de las ITU en embarazadas, reduciéndose la proporción de PNA e ITU por Escherichia coli.

BACKGROUND: Urinary tract infection (UTI) is the most frequent bacterial infectious pathology during pregnancy. Efforts to accomplish an early detection and treatment are based on universal urine culture during pregnancy, study of etiologic agents and their susceptibility to antimicrobials prescripted during pregnancy. OBJECTIVE: To describe the clinical and microbiological characteristics of cases of UTI in pregnant women attended in our institution during 2007 and compare them with the reports of 1988 and 2001. METHODS: Clinical records of 112 pregnant women who presented UTI were reviewed, establishing the frequency of acute pyelonephritis (APN), infectious agent and antimicrobial susceptibility. Data were compared statistically with the records of 2001 and 1988 by calculating odds ratios. RESULTS: The proportion of APN showed a decreasing trend between 1988, 2001 and 2007 (p<0.001). Escherichia coli was the most frequent infectious agent, although its frequency reduced between 2001 and 2007 (OR 0.32; IC95% 0.17-0.58). On the other hand, the frequency of UTI caused by Streptococcus agalactiae (GBS) increased during the same period of time (OR 3.98; 1.85-8.67). Antimicrobial susceptibility to ampicillin, gentamicin, nitrofurantoin y cotrimoxazole did not present significant differences between 2001-2007. CONCLUSION: A change in the clinical and microbiological characteristics of UTI in pregnant women was documented. The proportion of APN and UTI caused by Escherichia coli were reduced.