A comparison of antimicrobial sensitivities of urinary pathogens for the years 1980 and 1990

Increasing resistance to quinolones: A four-year prospective study of urinary tract infection pathogens

A four-year prospective study was carried out to determine the incidence and rate of development of resistance by common urinary tract infection (UTI) pathogens to quinolone antimicrobial agents. Results show that there is high intrinsic resistance to the quinolones among strains of Pseudomonas aeruginosa (43.4%), Escherichia coli (26.3%), and Proteus spp. (17.1%). Over four years, rising rates of resistance were observed in P. aeruginosa (14.6% increase), Staphylococcus aureus (9.8%), and E. coli (9.7%). The highest potency was exhibited by ciprofloxacin (91.2%), levofloxacin (89.2%), and moxifloxacin (85.1%), while there were high rates of resistance to nalidixic acid (51.7%) and pefloxacin (29.0%). Coliforms, particularly E. coli (>45%), remain the most prevalent causative agents of UTI while females within the age range of 20-50 years were most vulnerable to UTI.

Antibiotic sensitivity of bacteria associated with community-acquired urinary tract infection in Britain

Twelve laboratories in different parts of Britain each supplied approximately 80 consecutive urinary bacterial isolates from community patients. All strains were identified by a central laboratory, where sensitivity to a variety of orally administered antimicrobials was determined by microtitre broth dilution. 65.1% of isolates were Escherichia coli, 23.4% 'coliforms' other than E. coli, 4.6% Proteus and Morganella spp., 1.8% Pseudomonas spp., 2.4% enterococci, 0.7% group B streptococci, 1.5% coagulase-negative staphylococci and 0.5% Staphylococcus aureus. Using previously published breakpoint sensitivity values, 98.9% of all isolates were found to be sensitive to norfloxacin and to ciprofloxacin, 95.7% to co-amoxiclav, 86.8% to nitrofurantoin, 77.4% to cephalexin, 75.6% to trimethoprim, 75.0% to cephradine and 51.7% to amoxycillin. There were some differences in sensitivities between centres, particularly those of the cephalosporins. Using standard breakpoints, submitting laboratories were found to overestimate sensitivity to nitrofurantoin and to underestimate sensitivity to the quinolones and to co-amoxiclav; there was considerable overestimation of sensitivity to cephalosporins.

Extended spectrum beta-lactamase production and fluorquinolone resistance in pathogens associated with community acquired urinary tract infection

We have evaluated the susceptibility of 199 pathogens isolated in pure culture from consecutive urine samples submitted from the community. Rates of susceptibility for all organisms were ampicillin, 48%; amoxycillin/clavulanic acid, 88%; cephalothin, 57%; cefuroxime axetil, 74%; nalidixic acid, 85%; ciprofloxacin, 99%; nitrofurantoin, 78%; and trimethoprim, 67%. Ciprofloxacin resistance and production of extended spectrum beta-lactamase enzymes were detected in Escherichia coli strains isolated from patients in the community.

Prophylaxis for transrectal prostatic biopsies: a randomized controlled study of intravenous co-amoxiclav given as a single dose compared with an intravenous dose followed by oral co-amoxiclav for 24 h

OBJECTIVE

To compare in a randomized prospective study the infective complication rates of a single intravenous dose of co-amoxiclav given alone before transrectal prostatic biopsy with an intravenous dose followed by oral co-amoxiclav for 24 h.

PATIENTS AND METHODS

Eighty-three patients undergoing prostatic biopsy were randomized to receive 1.2 g co-amoxiclav intravenously and then either three further doses of oral co-amoxiclav (Group 1) or no further antibiotics (Group 2). The evaluation included analysis of a mid-stream urine (MSU) sample before and 72 h after biopsy, and the recording of oral temperatures and symptoms in the first 44 patients. Patients with symptomatic urinary tract infections (UTIs), prostatitis, indwelling catheters, diabetes and those receiving steroid therapy were excluded.

RESULTS

Eight patients, four from each treatment arm, were found to have asymptomatic UTIs from their MSU before biopsy. Excluding these patients, four patients (11%) from Group 1 and six from Group 2 (16%) had positive MSUs at 72 h; two patients from Group 2 and one from Group 1 required admission to hospital. Of the patients returning symptom and temperature charts, a further six (14%; three from each group) reported signs and symptoms suggestive of infection despite negative urine cultures.

CONCLUSIONS

There was no statistically significant difference in the rate of positive MSUs between the groups. The incidence of infections was considerably higher than in previously published series where other antibiotics were used, suggesting that co-amoxiclav is not the drug of choice for transrectal prostatic biopsy.

Diagnosis and treatment of uncomplicated urinary tract infection

Acute uncomplicated urinary tract infection is one of the most common problems for which young women seek medical attention and accounts for considerable morbidity and health care costs. Acute cystitis or pyelonephritis in the adult patient should be considered uncomplicated if the patient is not pregnant or elderly, if there has been no recent instrumentation or antimicrobial treatment, and if there are no known functional or anatomic abnormalities of the genitourinary tract. Most of these infections are caused by E. coli, which are susceptible to many oral antimicrobials, although resistance is increasing to some of the commonly used agents. Review of the published data suggests that a 3-day regimen is more effective than a single-dose regimen for all antimicrobials tested. Regimens with trimethoprim-sulfamethoxazole seem to be more effective than those with beta lactams, regardless of the duration. Because of increasing resistance to trimethoprim-sulfamethoxazole, an alternative regimen such as nitrofurantoin (in a 7-day regimen), a fluoroquinolone, or an oral third-generation cephalosporin may be a better empiric choice in some areas. Acute pyelonephritis caused by highly virulent uropathogens in an otherwise healthy woman may be considered an uncomplicated infection. The optimal treatment duration for acute uncomplicated pyelonephritis has not been established, but 10- to 14-day regimens are recommended. We prefer to use antimicrobials that attain high renal tissue levels, such as a fluoroquinolone, trimethoprim-sulfamethoxazole, or an aminoglycoside, for pyelonephritis. Acute uncomplicated cystitis or pyelonephritis in healthy adult men is uncommon but is generally caused by the same spectrum of uropathogens with the same antimicrobial susceptibility profile as that seen in women.

A review of the microbiology of amoxycillin/clavulanic acid over the 15 year period 1978-1993

A review of the published literature over the period 1978-1993 was undertaken to assess any changes in the prevalence of beta-lactamase-producing bacterial pathogens and also any changes in the susceptibility in these pathogens to amoxycillin/clavulanate. The review has involved the examination of over 1500 publications. The review shows that in general there has been an increase in the frequency of beta-lactamase-producing pathogens resistant to ampicillin and amoxycillin but there is no evidence for any significant increase in resistance to amoxycillin/clavulanate over the period of the review.