Ciprofloxacin Resistance Rates Research Articles

Genotypic Diversity and Characterization of Quinolone Resistant Determinants from Enterobacteriaceae in Yaoundé, Cameroon

Background: Enterobacteriaceae causes many types of infections which are often treated with quinolones and fluoroquinolone (Q/FQ). The resistance mechanisms to Q/FQ are usually associated with mutations in the quinolone resistance determining region which alter the conformation of target amino acid residues within the protein and in the qnr genes. This study aimed at determining the antimicrobial resistant profile of a sample of Enterobacteriaceae from Cameroon and the genetic diversity in quinolone-resistant isolates in view of implementing a better management, treatment, control and prevention of the transmission of these resistant strains. Methods: Identification and antimicrobial susceptibility testing was done using VITEK 2. The detection of plamid-mediated quinolone resistance (PMQR) genes was carried out using the conventional PCR method. Sequencing was done using the Applied Biosystem 3500 genetic analyser. DNA fingerprint was obtained using Pulsed-Field Gel electrophoresis. Results: Among 440 Enterobacteriaceae, the most prevalent genera were: Escherichia 178/440 (39.5%); Klebsiella 148/440 (33.6%); Enterobacter 35/440 (8%); Pantoea 28/440 (6.4%); Proteus 14/440 (3.2%) Salmonella 13/440 (3%). Ampicillin resistance showed the highest prevalence with 371/440 (81%) and Imipenem the lowest resistance 9/440 (2.1%). The ciprofloxacin resistance rate was 161/440 (36.6%). The detected plasmid mediated quinolone resistance (PMQR) genes were: qnrA, 2/161 (1.2%); qnrB, 31/161 (19.3%); qnrS, 13/161 (8.1%): Aac (6')Ib-cr, 84/161 (52.2%) and qepA, 3/161 (1.9%). There were several mutations in the parC gene of Klebsiella leading to S80D and S80N substitutions. Two pairs of Klebsiella peumoniae strains were phenotypically and genotypically identical with 100% similarity in the dendrogramme. Conclusion: This study showed that quinolone resistance was high. The PMQR genes contributing to this resistance were diverse. This high PMQR indicates that there has been an unknown circulation of these genes in our community. To avoid the rapid dissemination of these PMQR genes continuous surveillance of antimicrobial resistance should be carried out not only in humans but also in animals to monitor the evolution of these genes.

A meta-analysis of antibiotic resistance rates in Pseudomonas aeruginosa isolated in blood cultures in Turkey between 2007 and 2017.

OBJECTIVE:The prevalence of Pseudomonas aeruginosa has remained stable in recent years, and resistant strains has increased dramatically. In this meta-analysis, we aimed to analyze the P. aeruginosa strains isolated from blood cultures in Turkey during the last 11 years and to reveal their antimicrobial susceptibility.METHODS:Data collected between 2007 and 2017 were divided into two groups as Group-1; 2007–2011 and Group-2; 2012–2017. The differences in antibiotic resistance rates between Group-1 and Group-2 were analyzed. The study data were included according to PRISMA criteria, then meta-analysis was performed.RESULTS:A total of 30 study data from 25 studies were included in the study. The prevalence rate of meropenem (MEM) resistance in P. aeruginosa in Turkey was 25.1% (95% Cl: 20.65–29.83) according to a meta-analysis of 637 isolates. MEM resistance rates in Group-1 and Group-2 were 23.4% (95% Cl: 18.34–28.99) and 29.3% (95% Cl: 21.23–38.23), respectively. The prevalence rate of imipenem (IMP) resistance in P. aeruginosa in Turkey was 26.8% (%95 Cl: 23.40–30.35) according to a meta-analysis of 1421 isolates. IMP resistance rates in Group-1 and Group-2 were 26.2% (95% Cl: 22.41–30.27) and 28.4% (95% Cl: 21.57–35.88), respectively. Ciprofloxacin (CIP) resistance rate was 27.04% (95% Cl: 21.88–32.52) in 1388 isolates. CIP resistance rates in Group-1 and Group-2 were 30.8% (95% Cl: 24.35–37.56) and 18.6% (95% Cl: 10.72–28.11), respectively. The prevalence rate of piperacillin-tazobactam (TZP) resistance in P. aeruginosa in Turkey was 29.2% (95% Cl: 21.058–38.088) according to a meta-analysis of 1030 isolates. TZP resistance rates in Group-1 and Group-2 were 26.1% (95% Cl: 17.76–35.31) and 38.2% (95% Cl: 18.48–60.27), respectively.CONCLUSION:There is a remarkable increase in resistance rates in P. aeruginosa to MEM and TZP in Turkey due to frequent use. Other antibiotics with antipseudomonal effect should be prioritized in the treatment of these infections.

Resistance profile to antimicrobials agents in methicillin-resistant Staphylococcus aureus isolated from hospitals in South Brazil between 2014-2019.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen causing healthcare-associated infections. Owing to the restricted use of beta-lactams in MRSA infections, non-beta-lactam antimicrobials are required for treatment. However, MRSA can develop resistance mechanisms to non-beta-lactam antimicrobials, which reduces viable treatment options. Here, we evaluated the antimicrobial susceptibility and resistance genes of MRSA isolated from hospitalized patients in South Brazil. METHODS: The antimicrobial susceptibilities of hospital MRSA (217) isolates were determined by disk diffusion or microdilution methods. Additionally, the presence of 14 resistance genes and SCCmec typing was performed by PCR. RESULTS: Among the antimicrobials tested, we observed high erythromycin (74.2%), ciprofloxacin (64.5%), and clindamycin (46.1%) resistance rates and complete susceptibility to linezolid and vancomycin. Seventeen different patterns of MRSA antimicrobial resistance were observed, of which 42.9% represented multidrug resistance. Among erythromycin-resistant MRSA, 53.4%, 45.3%, 37.9%, 13.0%, and 6.8% carried ermA, msrA, msrB, ermC, and ermB genes, respectively. Among clindamycin-resistant MRSA, 83%, 17%, 10%, 4%, and 2% carried ermA, ermC, ermB, linA, and linB genes, respectively. Among gentamicin-resistant MRSA, 96.8%, 83.9%, and 9.7% carried aac(6')/aph(2''), aph(3’)-IIIa, and ant(4’)-Ia genes, respectively. Among tetracycline-resistant MRSA, 6.5% and 93.5% carried tetK and tetM genes, respectively. Lastly, among trimethoprim/sulfamethoxazole-resistant MRSA, 13.3% and 100% carried dfrA and dfrG genes, respectively. The SCCmec type IV isolates were detected more frequently, whereas the SCCmec type III isolates exhibited higher multidrug resistance. CONCLUSIONS: The study data provides information regarding the MRSA resistance profile in South Brazil that is associated with the clinical conditions of patients and can contribute to clinical decision-making.

Antimicrobial resistance patterns of Uropathogens isolated from adult women with acute uncomplicated cystitis

BackgroundTo evaluate the antibiotic resistance patterns of uropathogens isolated from adult women with acute community-acquired (CA) uncomplicated cystitis.ResultsOver a one-year period (May 2015–April 2016), the results of susceptibility testing of outpatient midstream urine samples from 5 different laboratories were prospectively evaluated. The study included only adult women with uncomplicated cystitis. The susceptibility testing in all laboratories was performed using the disk diffusion method with the VITEK-2 Compact system. The isolated uropathogens and their resistance to the tested antibiotics were evaluated. Out of 317 adult women with CA uncomplicated cystitis, 179 had a positive culture. The most commonly isolated organism was Escherichia coli (E. coli) (70.4%), followed by Klebsiella (21.2%). The overall resistance rate was highest for ampicillin (85.6%), followed by cefalotin (56.3%), trimethoprim/sulfamethoxazole (54.7%), pipracillin (51.9%), nitrofurantoin (48.8%) and aztreonam (47.4%). Isolated E. coli strains were commonly resistant to ampicillin (80.5%), trimethoprim/sulfamethoxazole (72.2%) and aztreonam (71.4%), followed by cefalotin (55.9%). The overall ciprofloxacin resistance rate was 17.9%, and the resistent was found only with E. coli (25.4%).ConclusionsOur results may aid in the selection of proper empiric antibiotic therapy for adult women with acute CA uncomplicated cystitis.

1672. Imported Enteric Fever in an Ethnically Diverse Area of London

BackgroundTyphoid is a leading cause of fever in returning travelers, particularly those visiting friends and relatives in the Indian subcontinent. We reviewed a cohort of patients with enteric fever from our hospitals in North West London, which serves a large Indian resident population.MethodsRetrospective analysis of electronic laboratory, microbiology and medical records of all patients with blood cultures positive for Salmonella enterica serotypes typhi (S.typhi) or paratyphi (S.paratyphi) A, B and C from January 1, 2016 to December 31, 2018 at London North West University Healthcare NHS Trust. Organisms were cultured on selective media and identified by API 20E (BioMerieux) or MALDI TOF MS (Bruker).Results37 blood cultures positive for S.typhi were identified from 26 patients and 37 blood cultures positive for S.paratyphi were identified from 23 patients. The median age was 28 years (range 1–79 years). Infection was more common in males (27/49, 55%) compared with females (22/49, 45%) but this was not statistically significant. Most patients (31/49) had traveled to India. Travel history was not identified for 9 patients. Laboratory results at presentation were available for all patients. Lymphopenia (defined as <1.5 × 109/L) was found in 12/23 (52%) patients with S.paratyphi compared with 10/26 (38%) of those with S. typhi. Thrombocytopenia (defined as <150 × 109/L) was found equally in both groups (22% in S. paratyphi, 27% in S. typhi). Raised alanine transferase (ALT) (defined as >35 IU/L) was seen in 14/23 (61%) in S. paratyphi compared with 19/26 (73%) in S. typhi. Median platelet count was similar in both groups (199 × 109/L in S. paratyphi, 202 × 109/L in S. typhi). Absolute eosinopenia was seen in all patients, consistent with other observational studies. For 3 patients, antibiotic sensitivities were not available. Regarding S. paratyphi cases, 16/21 (76%) were resistant to ciprofloxacin compared with 20/25 (80%) in S. typhi. Azithromycin resistance was seen in 5/46 (11%). All isolates were susceptible to third-generation cephalosporins.ConclusionThere is a high rate of ciprofloxacin resistance in this cohort of patients with enteric fever, confirming that the use of third-generation cephalosporins and macrolides in travelers to India is most appropriate for treatment.Disclosures All authors: No reported disclosures.

Comparison of emergency department to hospital antibiograms: Influence of patient risk factors on susceptibility

ObjectivesTraditional antibiograms use local resistance patterns and susceptibility data to guide empiric antimicrobial therapy selection. However, antibiograms are rarely unit-specific and do not account for patient-specific risk factors. MethodsThis retrospective, single-center descriptive study used culture and susceptibility data from January 1 to December 31, 2016 to develop an Emergency Department (ED)-specific antibiogram and compare the antimicrobial susceptibilities of the most commonly identified organisms to the hospital antibiogram. All ED isolates were further stratified by the following risk factors that may influence antimicrobial susceptibility: age, disposition from ED, previous antimicrobial use and/or hospitalization within 30 days, and presenting location (i.e. healthcare facility residence versus community). ResultsA total of 2158 isolates from the ED were included: Escherichia coli (n = 1244), Klebsiella pneumoniae (n = 232), Proteus mirabilis (n = 131), Pseudomonas aeruginosa (n = 103), Staphylococcus aureus (n = 303), and Enterococcus faecalis (n = 145). There were no statistically significant differences between the ED and hospital antibiogram (n = 5739) with the exception of Escherichia coli. The hospital antibiogram overestimated Escherichia coli resistance rates for cefazolin (20% vs 15.6%, p = 0.049), ceftriaxone (9.6% vs 6.4%, p < 0.033), and ciprofloxacin (23.7% vs 15.4%, p < 0.006). There were significantly more risk factors present in patients admitted versus discharged from the ED (p < 0.001). Healthcare facility residence had the greatest influence on susceptibility, especially Escherichia coli (81.8% vs 34.9%, p < 0.001) and Proteus mirabilis (75.3% vs 33%, p < 0.001) ciprofloxacin susceptibility. ConclusionsThere were no statistically significant differences between the ED and hospital antibiogram with the exception of Escherichia coli. However, development of an ED-specific antibiogram can aid physicians in prescribing appropriate empiric therapy when risk factors are included.

Australian Gonococcal Surveillance Programme Annual Report, 2017

The Australian Gonococcal Surveillance Programme (AGSP) has continuously monitored antimicrobial resistance in clinical isolates of Neisseria gonorrhoeae from all states and territories since 1981. In 2017, there were 7,835 clinical isolates of gonococci from public and private sector sources tested for in vitro antimicrobial susceptibility by standardised methods. Current treatment recommendations for gonorrhoea for the majority of Australia, is a dual therapeutic strategy of ceftriaxone and azithromycin. Decreased susceptibility to ceftriaxone (Minimum Inhibitory Concentration or MIC value 0.06-0.125 mg/L) was found nationally in 1.06% of isolates, which is lower than that reported in the AGSP Annual Report 2016 (1.7%). The highest proportions were reported from Victoria and Western Australia (urban and rural) (2.1% and 1.4% respectively). Resistance to azithromycin (MIC value ≥1.0 mg/L) was found nationally in 9.3% of isolates, which is approximately double the proportion reported in 2016 (5.0%) and more than three times the proportion reported in 2015 (2.6%). The highest proportions were reported from Victoria (13.5%), South Australia (12.8%) and New South Wales (9.3%). High level resistance to azithromycin (MIC value ≥256 mg/L) was reported in 4 strains nationally in 2017, 2 from Victoria, one from New South Wales, and one from Queensland. The proportion of strains resistant to penicillin in non-remote Australia ranged from 10.3% in non-remote Northern Territory to 44.1% in Tasmania. In remote Northern Territory, penicillin resistance rates remain low (2.5%). In remote Western Australia, penicillin resistance rates continue to increase (6.7%) compared to the previous years, however, there were relatively low numbers of strains available for isolate based testing (n=12). To address this and to monitor resistance and inform treatment guidelines, widespread molecular testing for penicillin resistance in Western Australia is in place, and these data are included in the AGSP. The proportion of strains resistant to ciprofloxacin in non-remote Australia ranged from 17.2% in non-remote Northern Territory to 61% in Tasmania. Ciprofloxacin resistance rates remain comparatively low in remote Northern Territory (1.3%) and remote Western Australia (5.0%).

A snapshot of antimicrobial resistance in Mexico. Results from 47 centers from 20 states during a six-month period.

AimWe aimed to assess the resistance rates of antimicrobial-resistant, in bacterial pathogens of epidemiological importance in 47 Mexican centers.Material and methodsIn this retrospective study, we included a stratified sample of 47 centers, covering 20 Mexican states. Selected isolates considered as potential causatives of disease collected over a 6-month period were included. Laboratories employed their usual methods to perform microbiological studies. The results were deposited into a database and analyzed with the WHONET 5.6 software.ResultsIn this 6-month study, a total of 22,943 strains were included. Regarding Gram-negatives, carbapenem resistance was detected in ≤ 3% in Escherichia coli, 12.5% in Klebsiella sp. and Enterobacter sp., and up to 40% in Pseudomonas aeruginosa; in the latter, the resistance rate for piperacillin-tazobactam (TZP) was as high as 19.1%. In Acinetobacter sp., resistance rates for cefepime, ciprofloxacin, meropenem, and TZP were higher than 50%. Regarding Gram-positives, methicillin resistance in Staphylococcus aureus (MRSA) was as high as 21.4%, and vancomycin (VAN) resistance reached up to 21% in Enterococcus faecium. Acinetobacter sp. presented the highest multidrug resistance (53%) followed by Klebsiella sp. (22.6%) and E. coli (19.4%).ConclusionThe multidrug resistance of Acinetobacter sp., Klebsiella sp. and E. coli and the carbapenem resistance in specific groups of enterobacteria deserve special attention in Mexico. Vancomycin-resistant enterococci (VRE) and MRSA are common in our hospitals. Our results present valuable information for the implementation of measures to control drug resistance.

Pooled prevalence and trends of antimicrobial resistance in Pseudomonas aeruginosa clinical isolates over the past 10 years in Turkey: A meta-analysis.

This meta-analysis aimed to evaluate the current prevalence and trends over the past 10 years of Pseudomonas aeruginosa (P. aeruginosa) antimicrobial resistance. Two researches independently searched two national (ULAKBİM, Türk Medline) and two international databases (PubMed, Web of Science) to identify studies on P. aeruginosa resistance to antimicrobials from 2007 to 2017. Homogeneity across studies was assessed using Cochrane guidelines, and total variability due to between-study variations was reflected in the I2 index. A random effects model was developed to estimate the antimicrobial resistance rates and their corresponding 95% CI. Pooled antibiotic resistance rates between 2007-2011 and 2012-2016 were compared to calculate the change in antibiotic resistance over time. Electronic searches with MeSH terms and text words identified 1017 papers. After applying exclusion and inclusion criteria, 45 articles were selected. Pooled resistance prevalence of P. aeruginosa to piperacillin-tazobactam, ceftazidime, cefepime, meropenem, imipenem, ciprofloxacin, gentamicin, amikacin, tobramycin and colistin were 33.9%, 38.6%, 35.6%, 30.1%, 28.0%, 30.7%, 28.2%, 17.8%, 15.7% and 2.2%, respectively. The resistance rates of piperacillin, piperacillin-tazobactam, imipenem, meropenem, amikacin and colistin significantly increased in the second 5 years (P<0.05); however, gentamicin, tobramycin and ciprofloxacin resistance rates significantly decreased (P<0.05). Comparing the resistance rates between the isolates of intensive care unit (ICU) patients and non-ICU patients, meropenem and piperacillin-tazobactam resistance in ICU isolates were significantly higher than non-ICU (P<0.05). These results suggest that antibiotic resistance is high in P. aeruginosa and the trends in antimicrobial resistance continue to increase, mainly in carbapenems and penicillins, in Turkey.

Antimicrobial resistance, virulence genes profiling and molecular relatedness of methicillin-resistant Staphylococcus aureus strains isolated from hospitalized patients in Guangdong Province, China.

PurposeThe main objective of this study was to decipher the prevalence, antimicrobial resistance, major virulence genes and the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolated from different clinical sources in southern China.Materials and methodsThe present study was performed on 187 non-duplicate S. aureus clinical isolates collected from three tertiary hospitals in Guangdong Province, China, 2010–2016. Antimicrobial susceptibility testing was performed by the disk diffusion method and by measuring the minimum inhibitory concentration. Screening for resistance and virulence genes was performed. Clonal relatedness was determined using various molecular typing methods such as multilocus sequence typing, spa and staphylococcal chromosomal cassette mec (SCCmec) typing. Whole genome sequencing was performed for three selected isolates.ResultsOut of 187 isolates, 103 (55%) were identified as MRSA. The highest prevalence rate was found among the skin and soft tissue infection (SSTI) samples (58/103), followed by sputum samples (25/103), blood stream infection samples (15/103) and others (5/103). Antimicrobial susceptibility results revealed high resistance rates for erythromycin (64.1%), clindamycin (48.5%), gentamicin (36.9%) and ciprofloxacin (33.98%). All isolates were susceptible to vancomycin. Resistance genes and mutation detected were as follows: aac(6’)-aph(2”) (24.3%), dfrG (10.7%), rpoB (21.4%), cfr (0%), fexA (1.94%), gyrA (35.92%), gyrB (0.97%), grlA (20.4%), grlB (10.68%), ermA (21.4%), ermB (18.44%), ermC (21.4%) and lnuA (18.44%). Profiling of virulence genes revealed the following: sea (11.7%), seb (21.4%), sec (0.97%), sed (0.97%), hla (86.41%), hlb (17.48%), hlg (10.68%), hld (53.4%), Tsst-1 (3.9%) and pvl (27.2%). Clonal relatedness showed that ST239-SCCmecA III-t37 clone was the most prevalent clone.ConclusionOur study elucidated the prevalence, antibiotic resistance, pathogenicity and molecular characteristics of MRSA isolated from various clinical sources in Guangdong, China. We found that the infectious rate of MRSA was higher among SSTI than other sources. The most predominant genotype was ST239-SCCmecA III-t37 clone, indicating that ST239-t30 clone which was previously predominant had been replaced by a new clone.

High frequency of mutations in gyrA gene associated with quinolones resistance in uropathogenic Escherichia coli isolates from the north of Iran.

Objective(s):Regarding the global burden of uropathogenic Escherichia coli (UPEC) infections, prevention and treatment of such infections play a significant role in healthcare management. The inordinate use of fluoroquinolones led to a worldwide spread of quinolone-resistant strains. Therefore, this study aimed to investigate mutations in codons 83 and 106 of gyrA gene in UPEC isolates in the north of Iran.Materials and Methods:This cross-sectional study performed on a total of 223 UPEC isolates which were recovered within 6 months in 2017. Isolates were identified and confirmed by standard microbiologic tests, and antimicrobial susceptibility testing was carried out by disk diffusion and E-test methods. PCR reaction was performed to amplify gyrA gene, and PCR-RFLP was performed using BsiEI and BstUI restriction enzymes to investigate mutations in gyrA gene.Results:The nalidixic acid, ciprofloxacin, ofloxacin, and norfloxacin resistance rates were 61.9%, 50.2%, 48.25, and 45.3%, respectively. Overall, 55.2% of E. coli isolates had a mutation in gyrA gene in codon 83, and 20.2% in codon 106. Also, 15.2% of isolates had simultaneously mutation. Moreover, a significant association was found between mutations in gyrA gene and quinolone and fluoroquinolones resistance pattern of UPEC isolates.Conclusion:Our results revealed a high level of quinolone resistance associated with the mutations in gyrA among the clinical isolates of UPEC in our region. To the best of our knowledge, this study is the first investigation on the role of gyrA alteration in quinolone resistance among UPEC isolates from the north of Iran.

214. Antimicrobial Usage and Outcomes following Laboratory Suppression of Antimicrobial Susceptibility Results for Pseudomonas aeruginosa in Sputum Cultures

Background Pseudomonas aeruginosa isolates from sputum cultures do not always require treatment, often representing chronic airways colonization. By releasing sputum P. aeruginosa antimicrobial susceptibility results, only after specific phone request by treating doctors, we aimed to reduce the use of ciprofloxacin without compromising clinical outcomes.MethodsFrom February 26, 2015, antimicrobial susceptibility results for P. aeruginosa in sputum were routinely suppressed except for immunosuppressed, Intensive Care Unit, cystic fibrosis, or bronchiectasis patients. A database search of the Wollongong Hospital Microbiology laboratory information system identified 108 patients with susceptibility results suppressed (February 26, 2015–February 25, 2017), compared with 108 patients where antimicrobial susceptibility results were routinely reported (February 26, 2013–February 25, 2015). Data collected included age, sex, residency, admission date and diagnosis, comorbidities, allergy, empirical and definitive antibiotic treatment, date of sputum culture, resistance patterns of P. aeruginosa, ciprofloxacin usage, antimicrobial stewardship interventions, length of stay, inpatient mortality, and readmission within 30 days.ResultsThe prevalence of P. aeruginosa in sputum cultures was 11% (1,252/11,388). Patient characteristics were comparable in the two groups. Ciprofloxacin use was significantly reduced postintervention [26.9% (29/108) vs. 39.8% (43/108); P = 0.043] as well as Guidance MS approvals [9.03% (87/963) vs. 17.72% (188/1,061); P = 0.000001]. Interrupted time series analysis of this intervention was not associated with a significant change in the rates of ciprofloxacin use. Rates of ciprofloxacin resistance were lower postintervention [2.8% (3/108) vs. 16.7% (18/108); P = 0.0006], reaffirmed by SQL database search of the OMNI-Client [9.30% (32/343) vs. 15.00% (60/399); P = 0.0187]. Ciprofloxacin usage against resistance over time There was no difference in length of stay, 30-day readmission, and mortality.ConclusionThis study offers a successful model of collaboration between the microbiology laboratory and antimicrobial stewardship activity. It showed a reduction in the use of ciprofloxacin with possible influence on P. aeruginosa resistance rates, without affecting patient outcomes.Disclosures All authors: No reported disclosures.

Distribution of virulence genes and their association with antimicrobial resistance among uropathogenic Escherichia coli isolates from Iranian patients

BackgroundUrinary tract infections (UTIs) are one of the most frequent diseases encountered by humans worldwide. The presence of multidrug-resistant (MDR) uropathogenic Escherichia coli (UPEC) harboring several virulence factors, is a major risk factor for inpatients. We sought to investigate the rate of antibiotic resistance and virulence-associated genes among the UPECs isolated from an Iranian symptomatic population.MethodsA total of 126 isolates from inpatients with UTI from different wards were identified as UPEC using the conventional microbiological tests. After identification of UPECs, all the isolates were subjected to antimicrobial susceptibility test and polymerase chain reaction (PCR) to identify the presence of 9 putative virulence genes and their association with the clinical outcomes or antimicrobial resistance.ResultsThe data showed that the highest and the lowest resistance rates were observed against ampicillin (88.9%), and imipenem (0.8%), respectively. However, the frequency of resistance to ciprofloxacin was found to be 55.6%. High prevalence of MDR (77.8%) and extended-spectrum β-lactamase (ESBL) (54.8%) were substantial. PCR results revealed the frequency of virulence genes ranged from 0 to 99.2%. Among 9 evaluated genes, the frequency of 4 genes (fimH, sfa, iutA, and PAI marker) was > 50% among all the screened isolates. The iutA, pap GII, and hlyA genes were more detected in the urosepsis isolates with significantly different frequencies. The different combinations of virulence genes were characterized as urovirulence patterns. The isolates recovered from pyelonephritis, cystitis, and urosepsis cases revealed 27, 22, and 6 virulence patterns, respectively. A significant difference was determined between ESBL production with pap GII, iutA, and PAI marker genes.ConclusionsOur study highlighted the MDR UPEC with high heterogeneity of urovirulence genes. Considering the high rate of ciprofloxacin resistance, alternative drugs and monitoring of the susceptibility profile for UPECs are recommended.

Using Core-genome Multilocus Sequence Typing to Monitor the Changing Epidemiology of Methicillin-resistant Staphylococcus aureus in a Teaching Hospital.

This study was performed to elucidate the changing epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in a Chinese teaching hospital. We performed whole-genome sequencing and phylogenetic analysis on MRSA isolates recovered at Sir Run Run Shaw Hospital (SRRSH) from 2013 to 2015. MRSA isolates underwent susceptibility testing, resistance determinant screening, virulence assays and clinical data analysis. A total of 292 MRSA infections were identified during the study period. Of these, most belonged to sequence type (ST) 5 (51.4%; 150 of 292) and ST59 (23.3%; 68 of 292). The proportion of ST5 MRSA decreased from 68.3% in 2013 to 32.1% in 2015, and the proportion of ST59 MRSA increased from 8.9% to 41.0%. Core-genome phylogenetic analysis revealed that ST59 MRSA isolates exhibited wider genotypic diversity than ST5 MRSA isolates in both healthcare-onset and community-onset groups. Minimum spanning trees showed that a cluster of ST5 MRSA was circulating at SRRSH, whereas the ST59 MRSA infections were mostly sporadic. ST59 MRSA caused 45.2% of the 93 skin and soft-tissue infection cases and displayed lower levofloxacin (11.8%) and ciprofloxacin (19.1%) resistance rates than the ST239 and ST5 MRSA isolates. ST59 healthcare-onset MRSA displayed enhanced virulence in the skin infection model and hemolysis assays. Notably, these isolates had virulence levels similar to those of classic community-associated MRSA strains. ST59 MRSA strains with high virulence potential have been replacing ST5 MRSA in predominance in SRRSH and causing nosocomial infections. Whole-genome sequencing is a powerful tool to monitor changes in the epidemiology of MRSA in hospitals.

Rise of antibiotic resistance in clinical enterococcal isolates during 2001-2016 in Iran: a review.

IntroductionThe clinical significance of enterococci is mostly related to its antibiotic resistance which contributes to colonization and infection, in particular amongst the hospitalized patients. The present review has examined the literature to provide a comprehensive data on enterococci antibiotic resistance during the last 20 years in Iran.MethodsSearch engines such as Google Scholar and PubMed were used to identify all Persian and English-language articles investigating enterococci in Iran from 1996 to 2017. The search terms were “enterococci”, “enterococcal”, “enterococcus”, “Iran”, “bacterial resistance”, “antibiotic resistance” and “resistance”.ResultsDecrease in the resistance trend against ampicillin, gentamycin and ciprofloxacin was observed over a period of 15 years (2001 to 2016) in Iran. During a 10 years period from 2001 to 2015, the rate of resistance among Enterococcus faecalis species was less than Enterococcus faecium. The resistancerate, however, was considerably increased for both species during this period. The mean resistance rates for vancomycin, gentamicin, ciprofloxacin, erythromycin, nitrofurantoin, chloramphenicol, trimethoprim-sulfametoxazol, imipenem and teicoplanin were higher among complicated cases (patients with underlying debilitating disorders) compared to general cases (hospitalized or outpatients with no specific underlying disorder).ConclusionsE. faecalis and E. faecium showed a rise in the mean resistance against all the antibiotics during a 10-year period from 2010 to 2015. With the exception of penicillin and ampicillin, resistance to all antibiotics was higher amongst complicated cases compared to general patients.

Results of a Multicenter Population Pharmacokinetic Study of Ciprofloxacin in Children with Complicated Urinary Tract Infection

Resistance rates for ciprofloxacin, which is labeled for treating complicated urinary tract infections in children, are rapidly rising. As there is limited knowledge on developmental pharmacology of ciprofloxacin, the primary aim of this study was to develop a population pharmacokinetic model for ciprofloxacin in children treated for complicated urinary tract infections. Children to whom ciprofloxacin was prescribed, intravenous (10 to 15 mg/kg body weight every 12 h) or per os (15 to 20 mg/kg every 12 h), were enrolled. One hundred eight serum and 119 urine samples were obtained during 10 intravenous and 13 oral courses of ciprofloxacin in 22 patients (age range, 0.31 to 15.51 years). A one-compartment model best described our data. Fat-free mass and glomerular filtration rate (estimated by a formula using cystatin C and creatinine), standardized for body surface area, were significant covariates for ciprofloxacin clearance. In our population, ciprofloxacin clearance is 0.16 to 0.43 liter/h/kg of body weight, volume of distribution 0.06 to 2.88 liters/kg, and bioavailability 59.6%. All of our patients had a clinical cure of their infection. Based on target attainment simulations across doses, all children reached the pharmacodynamic target for Enterobacteriaceae, but on average only 53% did for Pseudomonas aeruginosa and 3% for Staphylococcus aureus, at the 15-mg/kg oral dose. For treating urinary tract infections caused by Pseudomonas aeruginosa, oral doses should be at least 20 mg/kg. Furthermore, in our population, fat-free mass and kidney function should be considered, as they prove to be significant covariates for ciprofloxacin clearance and, hence, exposure. (This study has been registered at ClinicalTrials.gov under identifier NCT02598362.).

Human Campylobacteriosis in Italy: Emergence of Multi-Drug Resistance to Ciprofloxacin, Tetracycline, and Erythromycin.

Campylobacter spp. is one of the main cause of bacterial gastroenteritis in the world. The increase of antibiotic resistance in this species is a threat to public health. A Campylobacter spp. surveillance study was performed in Italy in the 2013–2016 period by the Enter-Net Italia network. The most prevalent Campylobacter species identified causing gastroenteritis was Campylobacter jejuni (73.4%) and 45% of all the annual cases of campylobacteriosis were reported in the summer period. High rates of ciprofloxacin and tetracycline resistance in Campylobacter spp. have been observed. An increasing percentage of Campylobacter coli strains simultaneously resistant to ciprofloxacin, tetracycline and erythromycin has been found. Molecular mechanisms of resistance have been investigated and the role of efflux pumps evaluated. Antibiotic resistance in Campylobacter spp. is an increasing serious threat that requires coordinated action to minimize the emergence and spread of antimicrobial resistant strains from animals to humans throughout the food chain.

Distribution of virulence-associated genes and antimicrobial susceptibility in clinical Acinetobacter baumannii isolates.

Acinetobacter baumannii is undoubtedly one of the most clinically significant pathogens. The multidrug resistance and virulence potential of A. baumannii are responsible for hospital-acquired nosocomial infections. Unlike numerous investigations on the drug-resistant epidemiology of A. baumanni, virulence molecular epidemiology is less studied. Here, we collected 88 A. baumannii clinical isolates, tested their antimicrobial susceptibility to 10 commonly used antibiotics and analyzed the distribution of 9 selected virulence-associated genes, aims to investigate the primary characteristics of the virulence-associated genes that exist in clinically multidrug resistant (MDR) and non-MDR isolates of A. baumannii. The MIC results showed the resistance rates of ciprofloxacin (68.2%, 60/88), gentamicin (67.0%, 59/88), amikacin (58.0%, 51/88), tobramycin (58.0%, 51/88), doxycycline (67.0%, 59/88), meropenem (54.5%, 48/88) and imipenem (65.9%, 58/88) were all above 50%, except for levofloxacin (34.1%, 30/88), minocycline (1.1%, 1/88) and polymyxin B (0%, 0/88). The Pulsed field gel electrophoresis (PFGE) analysis revealed that the resistance rate of MDR A. baumannii isolates in the Epidemic group was predominant (79.5%, 44/58), but in the Sporadic group was only 6.7% (2/30). Further investigation on the distribution of virulence genes showed the virulence genes bap (95.5%), surA1 (92.0%), BasD (92.0%), paaE (88.6%), pld (87.5%), BauA (62.5%), omp33-36 (59.1%) and pglC (53.4%) were accounted for high proportion, except for traT (0%). Overall, our results revealed that MDR isolates predominated in the Epidemic A. baumannii isolates, and contained a very high proportion of virulence genes, which may lead to high risk, high pathogenicity and high treatment challenge.

국내 병원획득 폐렴 원인균의 경험적 항균제에 대한 내성 현황

Background : Although the prevalence of antibiotic resistance may vary according to region, there is no guidance developed in Korea on the use of empirical antibiotics for the treatment of hospitalacquired pneumonia (HAP). The purpose of this study was to investigate the patterns of empiric antibiotic therapy and resistance of the isolated pathogens to the empirical antibiotics in the management of HAP in Korea. Methods : A retrospective analysis was conducted using the electronic medical records of the HAP patients January 2014-December 2015 in Korea. The patterns of prescribing empirical antibiotics and resistance of the isolated pathogens to the empirical antibiotics were examined. Results : A total of 170 patients was analyzed. Piperacillin/tazobactam was the key agent in the empirical antibiotics. The most common pathogen was Staphylococcus aureus (27.9%) followed by Acinetobacter baumannii (21.6%), Klebsiella pneumoniae (11.1%), Pseudomonas aeruginosa (6.3%), Stenotrophomonas maltophilia (5.8%), Enterobacter aerogenes (5.3%), and Escherichia coli (5.3%). The resistance rates of S. aureus to ciprofloxacin was 76%. E. coli had high level of resistance rate to ciprofloxacin (80%) and low resistance rate to imipenem (10%). K. pneumoniae and P. aeruginosa showed very high level of sensitivity to imipenem (100%) and cefepime (91.7%), respectively. To piperacillin/tazobactam, E. coli, E. erogenes, K. pneumoniae, and P. aeruginosa showed high level of sensitivity (52.4-100%). A. baumannii exhibited high-level resistance rates (63.4-85.4%) to the empirical antibiotics, including cefepime, ceftazidime, ciprofloxacin, imipenem, and piperacillin/tazobactam. Conclusion : The empirical antibiotic therapy was appropriate for the initial treatment of HAP owing to the adequate antibiotic coverage. Piperacillin/tazobactam was used in most patients and the most common pathogens including Pseudomonas aeruginosa had high level of sensitivity to the drug. The high level of resistance of A. baumannii to the empirical antibiotics is one of the major challenges in treating HAP.

Antimicrobial resistance of Neisseria gonorrhoeae in Germany: low levels of cephalosporin resistance, but high azithromycin resistance

BackgroundThe widespread antimicrobial resistance of Neisseria gonorrhoeae is a serious problem for the treatment and control of gonorrhoea. Many of the previously effective therapeutic agents are no longer viable. Because N. gonorrhoeae infections are not reportable in Germany, only limited data on disease epidemiology and antimicrobial susceptibility patterns are available. The Gonococcal Resistance Network (GORENET) is a surveillance project to monitor trends in the antimicrobial susceptibility of N. gonorrhoeae in Germany in order to guide treatment algorithms and target future prevention strategies.MethodsBetween April 2014 and December 2015, data on patient-related information were collected from laboratories nationwide, and susceptibility testing was performed on 537 N. gonorrhoeae isolates forwarded from the network laboratories to the Conciliar Laboratory for gonococci. Susceptibility results for cefixime, ceftriaxone, azithromycin, ciprofloxacin and penicillin were defined according to EUCAST 4.0 standards. Percentages, medians and interquartile ranges (IQR) were calculated.ResultsAltogether, 90% of isolates were from men. The median age was 32 (IQR 25–44) years for men and 25 (IQR 22–40) years for women (p-value < 0.001). The most frequently tested materials among men were urethral (96.1%) and rectal swabs (1.7%), and among women, it was mainly endocervical and vaginal swabs (84.3%). None of the isolates were resistant to ceftriaxone. Furthermore, 1.9% (in 2014) and 1.4% (in 2015) of the isolates were resistant to cefixime, 11.9% and 9.8% showed resistance against azithromycin, 72.0% and 58.3% were resistant to ciprofloxacin, and 29.1% and 18.8% were resistant to penicillin.ConclusionsResistance to ceftriaxone was not detected, and the percentage of isolates with resistance to cefixime was low, whereas azithromycin resistance showed high levels during the observation period. The rates of ciprofloxacin resistance and penicillin resistance were very high across Germany. Continued surveillance of antimicrobial drug susceptibilities for N. gonorrhoeae remains highly important to ensure efficient disease management.