Vol.63 No.2 March 2015
Antimicrobial therapy for urinary tract infections taking drug-resistant bacteria into consideration: obstetric and gynecologic points of view
Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Japan
Abstract
Urinary tract infections are infectious diseases encountered on a daily basis in most hospital departments, not only in Urology; and, in terms of the treatment strategies for this group of diseases, there is a need to treat urinary tract infection directly in each department, considering carefully its pathology. Recently, increased drug resistance against the causative bacteria of urinary tract infection has been reported, and the increased incidence of extended-spectrum beta-lactamase (ESBL) -producing bacteria has become a particular problem.
In the department of obstetrics and gynecology, urinary tract infections are commonly observed, for example after surgery for cervical cancer. However, owing to improvements in surgical techniques, such as nerve-sparing, early catheter removal, radical hysterectomy, and total self-catheterization, as well as the recent implementation of postoperative antibiotic administration, the incidence of postoperative urinary tract infection has been greatly reduced in recent years. Asymptomatic bacteriuria is characterized by persistent bacterial growth in the urine without any symptoms. In pregnancy, the reported frequencies of asymptomatic bacteriuria range from 2% to 7%, and appear to differ according to the parity, ethnicity, and socio-economic status of the women. In order for bacteriuria to be promptly and effectively treated, frequent screening of urine cultures for bacteriuria is recommended during early pregnancy.
In this study, we analyzed 1,556 cases of women undergoing labor in our hospital, and examined whether the incidence of acute pyelonephritis was related to gestational age, medical history, renal pelvis expansion, urine culture results, antibiotic use, the presence of antibiotic-resistant and ESBL-producing bacteria, and the patient and infant prognoses. We found that, while the reported rate of acute pyelonephritis in pregnant women is 1-2%, only 0.39% (n=6) of the women treated in our hospital developed this condition, likely owing to the fact that treatment was initiated at the time of onset of acute cystitis and asymptomatic bacteriuria.
Of the 6 patients with acute pyelonephritis, 3 patients presented with known urinary tract infection risk factors. Our results suggest that, during the prenatal care, detection and subsequent treatment of asymptomatic bacteriuria with frequent urine tests results in suppression of acute pyelonephritis onset in patients at risk.
Acute pyelonephritis is caused by bacteria, most commonly Escherichia coli, traveling through the ureters to the kidney. However, in this study, E. coli was also the causative organism in 3 out of the 6 patients. Considering the susceptibility to E. coli, the patients were given ceftriaxone empiric therapy, and recovered without causing pregnancy wastage due to pyelonephritis or as a result from serious complications. Thus, frequent examinations of urinary sediment are desirable in patients at risk. Risk factors for ESBL-producing bacterial urinary tract infection included antibiotic use in the previous 3 months, anemia, urinary tract catheterization, and long-term hospitalization. However, these findings should be interpreted with caution, since, in terms of obstetric cases, preterm labor may also be associated with some of these factors.
In conclusion, for urinary tract infections, and especially for those caused by ESBL-producing bacteria, prompt diagnosis and treatment with the appropriate antibiotics are highly important.
Key word
urinary tract infection, asymptomatic bacteriuria, extended-spectrum β-lactamases (ESBL), drug-resistance
Received
September 12, 2014
Accepted
November 21, 2014
Jpn. J. Chemother. 63 (2): 175-180, 2015
