Isolation and antimicrobial susceptibility pattern of Staphylococcus aureus in patients with surgical site infection at Debre Markos Referral Hospital,Amhara Region,Ethiopia

Background

Staphylococcus aureus, especially Methicillin Resistant Staphylococcus Aureus (MRSA) is a major health problem recognized as the most important nosocomial pathogen, often causing postoperative wound infections. Antibiotic resistance by MRSA has grown to be common, and resistance to almost all antibiotics has been found among these strains. The aim of this study was to determine the prevalence, antimicrobial susceptibility patterns and associated risk factors of S. aureus in patients with surgical site infections in an Ethiopian hospital.

Methods

A cross-sectional study was conducted from December 1, 2011 to March 30, 2012 among patients with surgical site infections at Debre Markos Referral Hospital, Debre Markos, Ethiopia. All wound swabs obtained from patients with surgical site infections during the study period were cultured on mannitol salt agar media which is selective for S. aureus. Isolated strains of S. aureus were tested for antibiotic susceptibility patterns using standard disc diffusion technique, and interpretation of resistance was done based on Clinical and Laboratory Standard Institute criteria. Univariate and multivariable analyses were used to assess the risk factors.

Results

Of the 184 surgical patients who had developed surgical site infection, S. aureus was isolated from 73 (39.7%) cases. Out of the 73 isolates of S. aureus, 36 (49.7%) were MRSA. Among the study participants, prevalence of MRSA was found to be 19.6%. The clinical isolates showed >80% level of resistance to ampicillin, amoxicillin, penicillin G, erythromycin, gentamicin and cotrimoxazole whereas <50% level of resistance was observed against clindamycin, oxacillin, tetracycline and vancomycin. MRSA strains showed resistance ranging from 5.6% (vancomycin) to 100% (cotrimoxazole). Of the following risk factors: sex, age, pus consistency, duration of operation, type of surgery, ward and hospital stay, laparotomy type of surgery was identified as a risk factor for infection by S. aureus.

Conclusion

The prevalence of S. aureus and/or MRSA infection in surgical and gynaecology & obstetrics wards of Debre Markos Referral Hospital was found to be high. The majority of isolates were highly resistant to major antimicrobial agents.     

Impact of an Antimicrobial Stewardship Program on Resistance to Fluoroquinolones of Urinary Enterobacteriaceae Isolated From Nursing Home Residents: A Retrospective Cohort Study

ObjectivesThis study investigated the impact of an antimicrobial stewardship program on fluoroquinolone (FLQ) resistance in urinary Enterobacteriaceae isolated from residents of 3 French nursing homes.DesignA multicentric retrospective before-and-after study was conducted.Setting and ParticipantsAll the first urinary Enterobacteriaceae isolates obtained from nursing home residents were included. Two time frames were analyzed: 2013-2015 and 2016-2017.MethodsThe antimicrobial stewardship program started in 2015 and was based on (1) 1-day training for use of an “antimicrobial stewardship kit for nursing homes;” and (2) daily support and training of the coordinating physician by an antibiotic mobile team (AMT) in 2 of 3 nursing homes.ResultsOverall, 338 urinary isolates were analyzed. Escherichia coli was the most frequent species (212/338, 63%). A significant reduction of resistance to ofloxacin was observed between 2013-2015 and 2016-2017 in general (Δ = −16%, P = .004) and among isolates obtained from patients hospitalized in the county nursing home with AMT support (Δ = −28%, P < .01). A nonstatistically significant reduction in ofloxacin resistance was also observed in the hospital nursing home with AMT support (Δ = −18%, P = .06).Conclusions and ImplicationsOur antimicrobial stewardship program resulted in a decrease in resistance to FLQ among urinary Enterobacteriaceae isolated from nursing home residents. The support of an AMT along with continuous training of the coordinating physician seems to be an important component to ensure efficacy of the intervention.     

Staphylococcus aureus native arthritis over 10 years

ObjectivesSeptic arthritis is associated with significant case fatality and morbidity. Staphylococcus aureus is the most common cause of arthritis. We aimed to analyze the microbiological features of S. aureus causing native arthritis and to investigate their influence on the clinical outcome of the infection.Patients and methodsWe conducted a retrospective study including all episodes of S. aureus native arthritis between 2005–2015. Phenotypic (antimicrobial susceptibility, β-hemolysis, agr functionality, biofilm formation) and genotypic characteristics (pulsed-field gel electrophoresis, DNA microarrays) were investigated. The primary endpoint was microbiological failure of treatment, including infection relapse, persistence, or attributable death.ResultsTwenty-nine patients were included (65.5% of men, mean age: 59): seven (24.1%) patients presenting with methicillin-resistant S. aureus (MRSA) native arthritis and 19 with methicillin-susceptible S. aureus (MSSA) native arthritis. Treatment failure occurred in seven (26.9%) patients (4/7 patients [57.1%] among MRSA infections vs. 3/19 [15.8%] among MSSA infections). The persistence rate was similar in MRSA and MSSA infections (1/7 vs. 3/19). However, the case fatality was significantly higher in patients with MRSA infection (3/7 vs. 0/19). The most frequent clonal complex (CC) was CC5 (38.1%). MSSA showed higher genetic variability (nine CCs) versus MRSA (3 CCs).ConclusionsBeyond methicillin resistance, we did not find phenotypic or genotypic factors associated with the poor outcome of S. aureus native arthritis. CC5 was the major CC, showing the higher genetic variability of MSSA versus MRSA.     

Prevalence and Spread of Multidrug Resistant Escherichia coli Isolates Among Nursing Home Residents in the Southern Part of the Netherlands

ObjectivesEmpiric antibiotic treatment should be based on recent surveillance data. Therefore, we conducted a surveillance of (multidrug) resistance of Escherichia coli and antibiotic use among Dutch nursing home (NH) residents. Pulsed-field gel electrophoresis and multilocus sequence typing were used to describe the spread of multidrug-resistant strains.DesignObservational study.SettingFive NHs in the southern part of the Netherlands.ParticipantsA total of 337 NH residents from both somatic and psychogeriatric wards.MeasurementsThe prevalence and spread of antibiotic resistance and multidrug resistant E. coli isolates collected from urine samples and antibiotic use among the NH residents were investigated.ResultsA total of 208 E. coli isolates were collected from 308 urine samples. Resistance to amoxicillin-clavulanic acid was 23% and resistance to ciprofloxacin was 16%. Resistance to trimethoprim-sulfamethoxazole was 19%, whereas nitrofurantoin resistance was less than 1%. Multidrug resistance was observed in 28 of the 208 isolates (13%). Several isolates showed a similar pulsed-field gel electrophoresis pulsotype and multilocus sequence typing type. Sequence type (ST) 131 was the most prevalent (48%) and was demonstrated in all NHs and with four different pulsotypes. Consumption of antibiotics for systemic use was 64.4 defined daily dose (DDD)/1000 residents/day. Amoxicillin-clavulanic acid was most frequently prescribed (20.92 DDD/1000 residents/day), followed by the quinolones (14.8 DDD/1000 residents/day).ConclusionWe observed a high prevalence of antibiotic resistance and antibiotic use. In particular, the use of and resistance to fluoroquinolones is concerning. Because of the high prevalence of resistance, many agents are no longer suitable for empiric treatment. E. coli ST131, which has also been demonstrated in this study, poses a potential risk to this vulnerable population. We have clearly demonstrated that the resistance among NH residents is different from elderly living at home and hospitalized patients, and with the emergence of resistant strains, such as ST131, NHs are a potential reservoir for multidrug resistant bacteria.     

Prevalence of plasmid-mediated AmpC β-lactamases among uropathogenic Escherichia coli isolates in southwestern Iran

ObjectivesThis study was undertaken to evaluate AmpC β-lactamase-producing Escherichia coli urine isolates and to characterize the frequency of plasmid-mediated AmpC (pAmpC)-encoding genes.MethodsAntimicrobial susceptibility tests were performed using the disk diffusion technique. AmpC β-lactamase production was assessed with a phenotypic inhibitor-based method. The presence of 6 pAmpC-encoding cluster genes was detected by multiplex polymerase chain reaction (PCR).ResultsThe proportion of antibiotic resistance of E. coli isolates ranged from 7.4% to 90.5%, and more than half (51.6%) of the total isolates were multidrug-resistant (MDR). Among the 95 E. coli isolates, 60 (63.2%) were found to be cefoxitin-resistant, but only 14 (14.7%) isolates were confirmed as AmpC β-lactamase-producers. In the PCR assay, pAmpC-encoding genes were found in 15 (15.8%) isolates, and bla_DHA was the most prevalent type. However, bla_FOX, bla_MOX, and bla_ACC genes were not detected in the isolates.ConclusionOur findings contributed valuable information concerning antibiotic resistance, confirmatory phenotypic testing for AmpC production, and pAmpC β-lactamase gene content in E. coli isolates in southwestern Iran. The level of MDR recorded in AmpC-producing strains of this study was worrying; therefore, implementing strong infection control approaches to reduce the MDR burden is recommended.     

Prevalence of Antimicrobial Resistance in Escherichia coli Strains Isolated from Fishery Workers

ObjectivesThis study aimed to characterize the prevalence of antibiotic resistance in Escherichia coli isolates from the fecal samples of fishery workers who work in fish farms and often use antibiotics for the feeding fishes.MethodsSeventy-three E. coli strains isolated from the fecal samples of fishery workers and 180 isolates from a control group of restaurant workers were tested for antibiotic resistance by agar disk diffusion with 16 antimicrobial agents.ResultsAbout 30% of isolates from each group showed antimicrobial resistance to ampicillin, and 60% of isolates from fishery workers and 41% from restaurant workers were resistant to tetracycline. The isolates showed higher resistance to cephalothin and cefoxitin than to other cephem antibiotics and to gentamicin than to other aminogycosides. Our data indicated that fecal E. coli isolates from fishery workers showed higher antibiotic resistance than those of non-fishery workers (restaurant workers), especially to cephalothin, tetracycline, and trimethoprim–sulfamethoxazole (p < 0.05). However, rates of multidrug resistance were similar among the fishery workers and restaurant workers.ConclusionFrequent use of antibiotics may cause increased antibiotic resistance in the human microbiome.     

Stratification by demographic and clinical data of the antibiotic susceptibility of Escherichia coli from urinary tract infections of the community

AimTo determine the patterns of antibiotic susceptibility of Escherichia coli strains isolated from adult patients with urinary tract infection (UTI), and to stratify the results by age and type of UTI to verify if there are statistically significant differences that can help physicians to prescribe better empirical antibiotherapy.DesignCross-sectional prospective study.LocationCommunity of Getafe (Madrid). Primary care level.Participants100 E. coli strains, randomly chosen, isolated from the urine (10⁴–10⁵ cfu/ml) of different patients from primary care centers in the Getafe area.Main measurementsThe antibiotic susceptibility of the strains was evaluated and the results were stratified by age and type of UTI. The clinical and demographic data of the patients were analyzed, classifying each episode as complicated UTI or uncomplicated UTI.ResultsStrains isolated from patients with uncomplicated UTI showed significantly greater susceptibility than those of complicated UTI to amoxicillin (65.9% vs. 30.6%, p = 0.001), amoxicillin/clavulanic acid (95.5% vs. 77.6%, p = 0.013) and ciprofloxacin (81.8% vs. 63.3%, p = 0.047). In complicated UTI, susceptibility to ciprofloxacin was significantly greater in the ≤65 years age group compared to the older age group (78.3% vs. 50%, respectively, p = 0.041). In the rest of antibiotics, no statistically significant differences were obtained when comparing by age (≤65 years versus >65 years), both in uncomplicated and complicated UTI.ConclusionsClinical and demographic data of patients with UTI are of great importance in the results of the antibiotic susceptibility in E. coli. Antibiograms stratified by patient characteristics may better facilitate empirical antibiotic selection for UTI in primary care.     

Prevalence of community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) in skin and soft tissue infections among cases from Puducherry, India

Aim

Methicillin resistant Staphylococcus aureus (S. aureus) is a major human pathogen which causes a wide range of hospital and community-acquired infections worldwide. Our objective is to describe the prevalence of MRSA within Puducherry, India.

Methods

A total of 172 patients treated with incision and drainage of soft tissue infections from March 2009 to September 2010 were included in the present study. We examined the antibiotic sensitivity pattern and the distribution of genes among MRSA isolates.

Results

In total, 72 isolates were obtained of which 51 were MRSA and 21 were methicillin sensitive S. aureus (MSSA). All the isolates showed absolute resistance pattern against beta lactam antibiotics (penicillin, ampicillin, amoxicillin) and were found to be sensitive towards macrolide and lincosamide antibiotics. The gene distribution among MRSA isolates showed the presence of femA, mecA, and lukS in 100, 94.4 and 69.4?% of the isolates respectively. The antibiotic sensitivity pattern and molecular characterization showed an increased prevalence of community acquired MRSA (CA-MRSA) in the study population.

Conclusion

The MRSA isolates were found to be sensitive to macrolide and lincosamide antibiotics but MSSA showed resistance pattern to the same. In this regard these antibiotics can be used for the effective treatment of MRSA at the expense of MSSA among the study population.     

Comparison of Antimicrobial Resistance in Escherichia coli Strains Isolated From Healthy Poultry and Swine Farm Workers Using Antibiotics in Korea

ObjectivesThe aim of this study is to compare the antibiotic resistance of Escherichia coli isolates from faecal samples of workers who often use antibiotics.MethodsA total of 163E coli strains isolated from faecal samples of livestock workers (poultry and swine farm workers) and restaurant workers in the same regions as a control group were analyzed by agar disc diffusion to determine their susceptibility patterns to 16 antimicrobial agents.ResultsMost of the tested isolates showed high antimicrobial resistance to ampicillin and tetracycline. The isolates showed higher resistance to cephalothin than other antibiotics among the cephems. Among the aminoglycosides, the resistance to gentamicin and tobramycin occurred at higher frequencies compared with resistance to amikacin and netilmicin. Our data indicated that faecal E coli isolates of livestock workers showed higher antibiotic resistances than nonlivestock workers (restaurant workers), especially cephalothin, gentamicin, and tobramycin (p < 0.05). Moreover, the rates of the livestock workers in the association of multidrug resistance were also higher than the rates of the restaurant workers.ConclusionThis study implies that usage of antibiotics may contribute to the prevalence of antibiotic resistance in commensal E coli strains of humans.     

Activité de 9 β-lactamines sur 280 souches d'Haemophilus influenzae résistantes à l'ampicilline par bêtalactamase et mécanisme non enzymatique

Clinical study – The in vitro activity (MIC) of 9 β-lactam agents was determined against 280 clinical isolates of H. influenzae exhibiting various mechanisms of resistance to ampicillin.Results – When β-lactamase was produced (the most frequent mechanism of antibiotic-resistance in H. influenzae) the MICs of amoxicillin were increased and, for the majority of these strains, the activity of the other β-lactam antibiotics was unchanged except for a few β-lactamase producing strains exhibiting less susceptibility to co-amoxiclav and cephalosporins. The study on 85 ampicillin resistant non-β-lactamase-producing H. influenzae strains of strains (ARNBL) showed an increase in the MICs of all β-lactam-agents. This increase was weak and variable according to β-lactam-agents and to the strains: the modal MIC value was increased 2 times for cefixime, cefotaxime, imipenem and 4 times for amoxicillin, co-amoxiclav, cefaclor, cefuroxime, cefpodoxime, and ceftriaxone. The clinical consequences are unknown; these strains are still rare and the resistance level is low. Understanding the intricacy of resistance mechanisms should lead to the development of reliable tests for the detection of such strains.     

Emergence of methicillin-resistant,vancomycin-intermediate Staphylococcus aureus among patients associated with group A Streptococcal pharyngitis infection in southern India

Beyond Staphylococcus aureus being an etiological agent for several serious clinical complications, the foot prints of S. aureus in pharyngitis infection has also been recently recognized. With due response to the fact, a prospective study was conducted between 2009 and 2010 to describe the molecular epidemiology of S. aureus in throat swabs of pharyngitis patients. A total of 63 methicillin-resistant S. aureus (MRSA) and 102 methicillin-susceptible S. aureus (MSSA) isolates were recovered from 265 throat swabs, representing a community-acquired outpatient population from Tamil Nadu, India. Molecular characterization of MRSA was done by two conventional multiplex PCR assays including Panton-Valentine leukocidin (PVL), mecA and nuc genes, and staphylococcal cassette chromosome mec (SCCmec) typing. Among 165 S. aureus isolates, methicillin resistance was observed in 38.2% (n = 63), in which 69.8% (n = 44/63) of the MRSA along with 55.9% (n = 57/102) of MSSA harbored PVL toxin genes. SCCmec typing showed 50.8% of isolates as SCCmec V (n = 32), 44.4% as SCCmec III (n = 28), and 1.6% as SCCmec types I, II and IVa (n = 1). Multilocus sequence typing performed for 26 selected MRSA isolates resulted in 12 different sequence types (ST), including a novel ST2129/SCCmec III, PVL-positive. Ten MRSA isolates were categorized as ST772 (38.5%)/SCCmec V, PVL-positive, and three isolates as ST368 (11.5%)/SCCmec III, PVL-negative. Though the prominent clones of ST772/SCCmec V were multidrug-susceptible worldwide, they were highly multidrug-resistant in the current study, including four clones intermediate to vancomycin. Totally, 10 (15.9%) out of 63 MRSA isolates were documented as vancomycin-intermediate S. aureus (VISA). Collectively, the present study for the first time portrayed the high prevalence of active MRSA pharyngitis infection and also emphasizes an alarming need for discrimination of pharyngeal-asymptomatic carriers of S. aureus from those with an active S. aureus pharyngitis infection.     

Résistance des souches d’Escherichia coli isolées de prélèvements d’origine urinaire vis-à-vis de l’association amoxicilline–acide clavulanique et divers antibiotiques

Objective

The aim of this study was to determine the antimicrobial activity of amoxicillin–clavulanic acid against Escherichia coli urinary strains, especially those resistant to amoxicillin, and to analyze the results according to the susceptibility testing methods.

Method

This prospective study was made from April to May 2008, on 301 E. coli strains isolated from urine samples. The susceptibility to antibiotics was studied by agar disk diffusion according to French Society of Microbiology Antibiogram Committee recommendations. MIC were determined with the E-test.

Results

According to the antibiogram, 59.8% of strains were resistant to amoxicillin, 33.2% to amoxicillin–clavulanic acid, 1.7% to cefotaxim, 8.3% to nalidixic acid, 6.6% to ofloxacin, 4.7% to ciprofloxacin, 4.7% to gentamicin and 38.1% to cotrimoxazole. After determining the MIC of E. coli strains resistant to amoxicillin and susceptible to amoxicillin–clavulanic acid, 37.5% (n = 30) remained susceptible, 61.25% (n = 55) were of intermediate susceptibility and only one strain (1.25%) was resistant.Among E. coli strains resistant to amoxicillin and intermediately susceptible to amoxicillin–clavulanic acid, 83.3% (n = 55) remained intermediately susceptible, 13.7% (n = 9) became susceptible and two strains (3%) were resistant.

Conclusion

The susceptibility testing methods, especially for amoxicillin–clavulanic acid, must be standardized to avoid the discrepancies noted between standard antibiograms and an accurate determination of MIC.     

Sensibilité aux antibiotiques des souches de Staphylocoques aureus isolées dans deux hôpitaux universitaires à Rabat,Maroc

Objectives

The aim of this study was to assess the in vitro activity of several antimicrobial agents against Staphylococcus aureus (S. aureus).

Method

This 2 year study was made in two Moroccan teaching hospitals. Four hundred and sixty-one non-repetitive clinical S. aureus strains were isolated and collected from various samples collected in several units between March 2006 and March 2008.The susceptibility of strains was determined by the agar disk diffusion method.

Results

The rate of methicillin resistance was 19.3% for S. aureus isolates. 53.93% of S. aureus strains were resistant to gentamycin, and all strains were susceptible to glycopeptides.

Conclusion

The rate of MRSA was high. Resistance to methicillin is often associated with resistance to gentamycin and fluoroquinolones. Vancomycin and teicoplanin were still effective on S. aureus in the two university hospitals.     

Growth inhibition of Escherichia coli and methicillin-resistant Staphylococcus aureus by targeting cellular methionine aminopeptidase

Methionine aminopeptidase (MetAP) catalyzes the N-terminal methionine excision from the majority of newly synthesized proteins, which is an essential cotranslational process required for cell survival. As such, MetAP has become an appealing target for the development of antimicrobial therapeutics with novel mechanisms of action. By screening a library of small organic molecules, we previously discovered a class of compounds that selectively inhibit the Fe(II)-form of MetAP. Herein, we demonstrate that some of these compounds and their newly synthesized derivatives halt the growth of Escherichia coli and Staphylococcus aureus cells with significant potency. The most potent compound inhibited methicillin-resistant S. aureus (MRSA) growth with an IC₅₀ value of 1 μM and MIC of 0.7 μg/ml. Two cell-based assays were used to verify that MetAP is the intracellular target in E. coli cells. These findings can serve as foundation for the development of novel therapeutics against an ever increasing threat by drug resistant staphylococcal infections.     

Methicillin-resistant Staphylococcus aureus among a network of French private-sector community-based-medical laboratories

Objective

The aim of this study was to estimate the frequency of methicillin-resistant Staphylococcus aureus (MRSA) strains in the French community and the proportion of Panton-Valentine (PVL)-MRSA.

Design

A cross-sectional study was made during a 3-month period in 2003 through a network of private-sector, community-based medical laboratories selected throughout France: the Labville network. Each MRSA isolate was included and characterized by French National Reference Center for Staphylococci. The total number of S. aureus isolates was also collected.

Results

Among the 283 patients infected or colonized by MRSA, 166 (59%) were considered as healthcare-associated, 14 (5%) as nursing-associated and 39 (14%) as community-acquired. The proportion of methicillin resistance among S. aureus was 14%. Taking into account the sampling design, the incidence of MRSA cases in French outpatients was estimated to be 0.50 [CI95%: 0.41–0.60] per 10,000 inhabitants. The molecular analysis confirmed that 80.6% belong to the Lyon clone, the most prevalent hospital MRSA clone spreading in France and 10.6% to a closely related clone. An emerging MRSA clone containing the tst1 gene was detected in six patients and the PVL-positive ST80 clone only in one, 22-year-old, patient.

Conclusion

Most of MRSA cases diagnosed in the community in France, in 2003, were elderly with specific risk factors and harbored hospital strains. The prevalence of PVL-MRSA remained low.     

Urinary tract infections in hospital pediatrics: Many previous antibiotherapy and antibiotics resistance,including fluoroquinolones

Objective

We studied antibiotic resistance in pediatric UTIs and we evaluated the impact of antibiotic exposure in the previous 12 months, very little French data being available for this population.

Methods

We conducted a multicenter prospective study including children consulting for, or admitted in 2 hospitals. Prior antibiotic exposure was documented from their health record.

Results

One hundred and ten patients (73 girls), 11 days to 12 years of age, were included in 10 months. Ninety-six percent presented with pyelonephritis, associated to uropathy for 25%. Escherichia coli was predominant (78%), followed by Proteus spp. and Enterococcus spp. The antibiotic resistance rate of E. coli was high and close to that reported for adults with complicated UTIs: amoxicillin 60%, amoxicillin-clavulanate 35%, cefotaxim 5%, trimethoprim-sulfametoxazole 26%, nalidixic acid 9%, ciprofloxacin 7%, gentamycin 1%, nitrofurantoin and fosfomycin 0%. The antibiotic exposure in the previous 12 months involved 62 children (56%) most frequently with β-lactams (89%) for a respiratory tract infection (56%). A clear relationship between exposure and resistance was observed for amoxicillin (71% vs. 46%), first generation (65% vs. 46%) and third generation (9% vs. 3%) cephalosporins, or trimethoprim-sulfamethoxazole (36% vs. 15%). However, antibiotic exposure could not account alone for the results, as suggested by the 7% of ciprofloxacin resistance, observed without any identified previous treatment.

Conclusion

Bacterial species and antibiotic resistance level in children are similar to those reported for adults. Antibiotic exposure in the previous 12 months increases the risk of resistance but other factors are involved (previous antibiotic therapies and fecal-oral or mother-to-child transmission).     

Epidemiology of Antibiotic Use for Urinary Tract Infection in Nursing Home Residents

ObjectivesDescribe antibiotic use for urinary tract infection (UTI) among a large cohort of US nursing home residents.DesignAnalysis of data from a multistate, 1-day point prevalence survey of antimicrobial use performed between April and October 2017.Setting and participantsResidents of 161 nursing homes in 10 US states of the Emerging Infections Program (EIP).MethodsEIP staff reviewed nursing home medical records to collect data on systemic antimicrobial drugs received by residents, including therapeutic site, rationale for use, and planned duration. For drugs with the therapeutic site documented as urinary tract, pooled mean and nursing home–specific prevalence rates were calculated per 100 nursing home residents, and proportion of drugs by selected characteristics were reported. Data were analyzed in SAS, version 9.4.ResultsAmong 15,276 residents, 407 received 424 antibiotics for UTI. The pooled mean prevalence rate of antibiotic use for UTI was 2.66 per 100 residents; nursing home–specific rates ranged from 0 to 13.6. One-quarter of antibiotics were prescribed for UTI prophylaxis, with a median planned duration of 111 days compared with 7 days when prescribed for UTI treatment (P < .001). Fluoroquinolones were the most common (18%) drug class used.Conclusions and ImplicationsOne in 38 residents was receiving an antibiotic for UTI on a given day, and nursing home–specific prevalence rates varied by more than 10-fold. UTI prophylaxis was common with a long planned duration, despite limited evidence to support this practice among older persons in nursing homes. The planned duration was ≥7 days for half of antibiotics prescribed for treatment of a UTI. Fluoroquinolones were the most commonly used antibiotics, despite their association with significant adverse events, particularly in a frail and older adult population. These findings help to identify priority practices for nursing home antibiotic stewardship.