Ciprofloxacin-resistant Infections Research Articles

Epidemiologic Associations Vary Between Tetracycline and Fluoroquinolone Resistant Campylobacter jejuni Infections.

Campylobacter jejuni is the leading cause of bacterial gastroenteritis and antibiotic resistant C. jejuni are a serious threat to public health. Herein, we sought to evaluate trends in C. jejuni infections, quantify resistance frequencies, and identify epidemiological factors associated with infection. Campylobacter jejuni isolates (n = 214) were collected from patients via an active surveillance system at four metropolitan hospitals in Michigan between 2011 and 2014. The minimum inhibitory concentration for nine antibiotics was determined using microbroth dilution, while demographic and clinical data were used for the univariate and multivariate analyses. Over the 4-year period, a significant increase in the recovery of C. jejuni was observed (p ≤ 0.0001). Differences in infection rates were observed by hospital and several factors were linked to more severe disease. Patients residing in urban areas, for instance, were significantly more likely to be hospitalized than rural residents as were patients over 40 years of age and those self-identifying as non-White, highlighting potential disparities in disease outcomes. Among the 214 C. jejuni isolates, 135 (63.1%) were resistant to at least one antibiotic. Resistance was observed for all nine antibiotics tested yielding 11 distinct resistance phenotypes. Tetracycline resistance predominated (n = 120; 56.1%) followed by resistance to ciprofloxacin (n = 49; 22.9%), which increased from 15.6% in 2011 to 25.0% in 2014. Resistance to two antibiotic classes was observed in 38 (17.8%) isolates, while multidrug resistance, or resistance to three or more classes, was observed in four (1.9%). Notably, patients with ciprofloxacin resistant infections were more likely to report traveling in the past month (Odds Ratio (OR): 3.0; 95% confidence interval (CI): 1.37, 6.68) and international travel (OR: 9.8; 95% CI: 3.69, 26.09). Relative to patients with only tetracycline resistant infections, those with ciprofloxacin resistance were more likely to travel internationally, be hospitalized and have an infection during the fall or summer. Together, these findings show increasing rates of infection and resistance and highlight specific factors that impact both outcomes. Enhancing understanding of factors linked to C. jejuni resistance and more severe infections is critical for disease prevention, particularly since many clinical laboratories have switched to the use of culture-independent tests for the detection of Campylobacter.

Treatment of Ciprofloxacin-resistant Ear Infections.

Ciprofloxacin resistance has been reported in 4.5% of patients with otorrhea and is increasing in prevalence. Due to ototoxicity, only fluoroquinolones are Food and Drug Administration approved for topical therapy in the middle ear. Furthermore, there is an assumption that antibiotic resistance is less relevant to topical therapy due to in vivo concentrations much higher than the minimum inhibitory concentration used to determine resistance. This study investigates ciprofloxacin-resistant infections and seeks to develop a better understanding of treatment options and outcomes. Retrospective review of 141 ciprofloxacin-resistant otologic infections. Tertiary-care hospital. Patients with culture-proven ciprofloxacin-resistant infections from 2008 to 2017. Antibiotic treatment with ciprofloxacin topical drops, ciprofloxacin plus oral antibiotics, and nonciprofloxacin therapy. Bacteriology for ciprofloxacin-resistant infections and treatment effectiveness of various therapies. Methicillin-resistant Staphylococcus aureus (33%), Corynebacterium striatum (19%), and non-Methicillin-resistant Staphylococcus aureus (11%) are the most frequent causes of ciprofloxacin-resistant infections. Topical ciprofloxacin monotherapy was successful in 2.7% of infections compared with a 64.7% success rate with the addition of an oral antibiotic (p < 0.001). Nonciprofloxacin drops are more effective with a 70% cure rate compared with the 2.7% of the ciprofloxacin drops p < 0.001. There was no difference in treatment efficacy when comparing nonciprofloxacin topical therapy (70% cure) to nonciprofloxacin topical therapy plus oral antibiotic (83% cure, p = 0.17). Using ciprofloxacin drops to treat ciprofloxacin-resistant bacteria is ineffective and patients do significantly better with alternative therapy. This finding supports the conclusion that high concentrations achieved in topical applications are not sufficient to overcome antibiotic resistance.

Emerging high-level ciprofloxacin resistance and molecular basis of resistance in Salmonella enterica from humans, food and animals

Disease caused by nontyphoidal serotypes of Salmonella enterica is the leading cause of foodborne illness worldwide. Many serotypes have also developed resistance to antimicrobials commonly used for the treatment of salmonellosis. Here we analyze 179 ciprofloxacin-resistant isolates identified among 3680 Salmonella isolated from humans, food, animals, and water collected in Shanghai, China. They were assessed for antimicrobial susceptibility, plasmid-mediated quinolone resistance (PMQR) determinants, and mutations in quinolone resistance determination regions (QRDRs); genetic relatedness was examined using PFGE. Ciprofloxacin resistance in Salmonella increased from 2.3% in 2006 to 5.9% in 2012. Multidrug resistance was common, and most carried mutations in QRDR (97.2%) and PMQR determinants (71.5%). Mutations frequently included changes in gyrA: Ser83Phe (53.6%) and Asp87Asn (35.8%), and in parC: Thr57Ser (53.1%) and Ser80Arg (44.1%). Mutations in parC and parE without changes in gyrA were identified in S. Derby and most S. Thompson. Among PMQR determinants, aac(6′)-Ib-cr (62.0%) and oqxA/oqxB (33.5%/33.0%) were most common, and conferred resistance without target mutations in five S. Typhimurium isolates. PFGE analysis revealed that S. Typhimurium, isolated from pork and aquatic products, and S. Indiana, isolated from chicken, were highly similar to isolates from humans, suggesting these products be the major source of ciprofloxacin-resistant infections. Our findings highlight the important role QRDRs and PMQR play in ciprofloxacin resistance of Salmonella, and reveal the potential sources of the pathogen associated with human infections.

Short‐Term and Medium‐Term Clinical Outcomes of Quinolone‐ResistantCampylobacterInfection

Campylobacter species is a leading cause of bacterial gastroenteritis worldwide. Quinolone resistance has emerged as an increasing problem among persons with Campylobacter infection over the past decade, but the clinical consequences are unclear. A case-comparison study of patients infected with ciprofloxacin-resistant or ciprofloxacin-susceptible Campylobacter species was conducted in Wales during the period 2003-2004. Campylobacter isolates were classified as resistant or susceptible to ciprofloxacin on the basis of standardized disk diffusion methods. Participants were interviewed by telephone at the time of illness, 3 months later, and 6 months later to compare disease severity, duration of illness, and medium-term clinical outcomes. There was no difference between 145 persons with ciprofloxacin-resistant infection and 411 with ciprofloxacin-susceptible infection with regard to the severity or duration of acute illness. Mean duration of diarrhea was similar in patients with ciprofloxacin-resistant versus ciprofloxacin-susceptible infection (8.2 vs. 8.6 days; P = .57) and did not alter significantly after adjustment for potential covariates, including age, underlying disease, foreign travel, use of antidiarrheal medication, and use of antimicrobials in a multiple linear regression model. There was no difference between case patients and comparison patients in the frequency of reported symptoms or in general practitioner consultation rates at either the 3-month or the 6-month follow-up interview. In this study, there was no evidence of more-severe or prolonged illness in participants with quinolone-resistant Campylobacter infection, nor was there evidence of any adverse medium-term consequences. This suggests that the clinical significance of quinolone resistance in Campylobacter infection may have been overestimated.

Risk factors for ciprofloxacin-resistant Campylobacter infection in Wales

To identify risk factors for ciprofloxacin resistance in both travel-related and domestically acquired Campylobacter infection. Case-comparison study of patients with ciprofloxacin-resistant and ciprofloxacin-susceptible Campylobacter infection conducted in Wales during 2003 and 2004. Foreign travel was the major risk factor for ciprofloxacin-resistant infection [adjusted odds ratio (adjOR) 24.0, 95% confidence interval (95% CI) 12.6-45.9]. Among travellers, case patients were five times more likely to drink still bottled water (adjOR 4.7, 95% CI 1.0-21.7), whilst among non-travellers, case patients were three times more likely to drink sparkling bottled water (adjOR 3.3, 95% CI 1.5-7.4). There was no increased risk associated with eating poultry or prior quinolone use. Foreign travel remains the most important risk factor for ciprofloxacin-resistant Campylobacter infection. The possible association of both domestic- and travel-related ciprofloxacin-resistant Campylobacter infection with bottled water needs to be further explored.

Prolonged diarrhea due to ciprofloxacin-resistant campylobacter infection.

Campylobacter causes >1 million infections annually in the United States. Fluoroquinolones (e.g., ciprofloxacin) are used to treat Campylobacter infections in adults. Although human infections with ciprofloxacin-resistant Campylobacter have become increasingly common, the human health consequences of such infections are not well described. A case-control study of persons with sporadic Campylobacter infection was conducted within 7 FoodNet sites during 1998-1999. The E-test system (AB Biodisk) was used to test for antimicrobial susceptibility to ciprofloxacin; ciprofloxacin resistance was defined as a ciprofloxacin minimum inhibitory concentration of > or =4 microg/mL. We conducted a case-comparison study of interviewed persons who had an isolate tested. Of 858 isolates tested, 94 (11%) were ciprofloxacin resistant. Among 290 persons with Campylobacter infection who did not take antidiarrheal medications, persons with ciprofloxacin-resistant infection had a longer mean duration of diarrhea than did persons with ciprofloxacin-susceptible infection (9 vs. 7 days [P=.04]). This difference was even more pronounced among the 63 persons who did not take antidiarrheal medications or antimicrobial agents (12 vs. 6 days [P=.04]). In a multivariable analysis-of-variance model, the persons with ciprofloxacin-resistant infection had a longer mean duration of diarrhea than did the persons with ciprofloxacin-susceptible infection (P=.01); this effect was independent of foreign travel. The association between ciprofloxacin resistance and prolonged diarrhea is consistent across a variety of analytical approaches. Persons with ciprofloxacin-resistant Campylobacter infection have a longer duration of diarrhea than do persons with ciprofloxacin-susceptible Campylobacter infection. Additional efforts are needed to preserve the efficacy of fluoroquinolones.

Ciprofloxacin resistance in Campylobacter jejuni: case-case analysis as a tool for elucidating risks at home and abroad.

To determine factors independently associated with the acquisition of a ciprofloxacin-resistant Campylobacter jejuni infection. Self-completion questionnaires were used to collect clinical, demographic and exposure data from cases of campylobacter infection reported to a sentinel surveillance scheme in England and Wales. Isolates from those cases were referred to the Public Health Laboratory Service Campylobacter Reference Unit for speciation, subtyping and antimicrobial resistance testing. Cases infected with a ciprofloxacin-resistant C. jejuni were compared with cases infected with a sensitive strain using case-case analysis. Single risk variable analysis and logistic regression analysis were employed. The analysis was restricted by travel status to control for the confounding effect of foreign travel. Over half (55%) of the campylobacter infections acquired abroad were resistant to ciprofloxacin, compared with 10% of UK-acquired strains [relative risk 5.23; 95% confidence interval (CI) 4.58-5.96]. For travel-associated cases, ciprofloxacin-resistant infections were independently associated with travel to Spain [odds ratio (OR) 6.87; 95% CI 3.52-13.38], Portugal (OR 22.40; 95% CI 4.36-114.99) or Cyprus (OR 11.74; 95% CI 1.28-108.02), and the consumption of chicken (OR 4.95; 95% CI 2.12-11.56) or bottled water (OR 3.70; 95% CI 1.69-8.10). Indigenous cases infected with a ciprofloxacin-resistant strain were more likely to report the consumption of pre-cooked cold meats (OR 2.13; 95% CI 1.44-3.13). The risk of acquiring a ciprofloxacin-resistant campylobacter infection was strongly associated with foreign travel. Restricting the analyses by travel status revealed different sets of risk exposures for acquiring a resistant C. jejuni strain, suggesting that different intervention strategies will be required.