1593. Analysis of Hospital Antimicrobial Susceptibility Test Results for Patterns of Antibiotic Resistance

Abstract Background Antimicrobial susceptibility tests (ASTs) are routinely performed on pathogens isolated from clinical samples. ASTs are used by clinicians to select the most appropriate treatment for antibiotic-resistant microorganisms. In aggregate, ASTs offer insight into the rise and spread of antibiotic resistance across hospitals. Here, we used ASTs to identify patterns of antibiotic resistance across drugs and microorganisms. Methods We conducted a retrospective analysis of 364,813 AST results from the University of Pittsburgh Medical Center from 2015 to 2018. Data regarding infection site, hospital laboratory testing, organism identification, and antibiotic susceptibilities were extracted from the laboratory information system and anonymized prior to use. The pathogens studied included Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Proteus mirabilis, and Enterococcus faecalis. Results We identified 21 antibiotic-pathogen combinations where resistance was found in less than 1% of AST results. Concordant susceptibility results of levofloxacin and ciprofloxacin occurred the most frequently among antibiotic pairs. Additionally, concordant susceptibility results were more common within antibiotics belonging to the same antibiotic class than between classes. P. aeruginosa had the highest rate of overall concordant results with concordance occurring within all -lactam classes. In contrast, K. pneumoniae and P. mirabilis showed the least concordance, suggesting that their resistance profiles are less predictable. Notably, we did not identify any pairs of antibiotics that strongly exhibited discordant susceptibility results regardless of the microorganism. Conclusion Using routinely collected clinical microbiological data, we were able to characterize pathogen-antibiotic combinations where resistance is rarely seen. Additionally, we identified pairs of antibiotics that frequently exhibited concordance susceptibilities both within and between classes. Lastly, we were unable to find evidence of discordant susceptibility results, indicating that more clinical research is needed to determine the efficacy of collateral sensitivity treatment techniques. Disclosures All authors: No reported disclosures.

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Bacterial Causes and their Antimicrobial Susceptibility Testing among Urinary Tract Infection Patients in Tobruk Area, Libya

AL-MUKHTAR JOURNAL OF SCIENCES ◽

10.54172/mjsc.v36i4.587 ◽

2021 ◽

Vol 36 (4) ◽

pp. 253-262

Author(s):

Mohammed T. Mostafa ◽

Khalid S. Mustafa ◽

Brijesh Kumar

Keyword(s):

Urinary Tract ◽

Antimicrobial Susceptibility ◽

Medical Center ◽

Laboratory Diagnosis ◽

Antimicrobial Susceptibility Tests ◽

Amoxicillin Clavulanic Acid ◽

Antibiotic Susceptibility Patterns ◽

Susceptibility Tests ◽

The Right ◽

Tract Infections

Urinary tract infections are very common among people of all ages, but the disease is more prevalent in women, so proper clinical and laboratory diagnosis, and the right treatment are very important to avoid complications and antimicrobial resistance. This study aimed to determine the bacterial causes and antibiotic susceptibility patterns of UTI patients. Recorded results of 6065 urine sample cultures and their antimicrobial susceptibility tests from the Department of Microbiology in Tobruk Medical Center, Tobruk City, were obtained from September 2016 to December 2018. The data was analyzed and discussed in compare with other studies. The study showed that a UTI is more common in females (78.8%) compared with male patients (21.2%). Gram-negative bacteria accounted for the majority of urinary pathogens (90%), where E. coli alone was (58.4%), klebsiellae (17.4%), Proteus (10.7%), while Pseudomonas species was the least common (3.3%) of the total. While the Gram-positive bacteria S. aureus constituted 9.6% of the total. The study was found statistically significant (P=0.000). The most effective antibiotics against all uropathogens were Imipenem and Amikacin, and less effective antibiotics were Ampicillin and Amoxicillin-clavulanic acid. This study concluded that the most common cause of UTI in Tobruk was Escherichia coli and the most effective antibiotics appear to be Imipenem and Amikacin.

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Variation in Methicillin-Resistant Staphylococcus aureus Occurrence by Geographic Location and Hospital Characteristics

Infection Control ◽

10.1017/s0195941700065814 ◽

1987 ◽

Vol 8 (4) ◽

pp. 151-157 ◽

Cited By ~ 35

Author(s):

Douglas S. Wakefield ◽

Michael Pfaller ◽

R. Michael Massanari ◽

Glenn T. Hammons

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Susceptibility ◽

Medical Center ◽

Geographic Location ◽

Mean Value ◽

Methicillin Resistant ◽

Hospital Size ◽

Antimicrobial Susceptibility Tests ◽

Susceptibility Tests ◽

Hospital Characteristics

AbstractA survey of 162 Veterans Administration Medical Center (VAMC) laboratories performing antimicrobial susceptibility testing was performed to determine variation in reported rates of methicillin-resistant Staphylococcus aureus (MRSA) isolation by geographic location and hospital characteristics. Of the 162 VAMC laboratories surveyed, 136 (84%) provided usable data. The percentage of S aureus isolates reported as resistant to methicillin ranged from 0% to 52% with a mean value of 10% among the 136 survey respondents. MRSA were isolated in every VA Medical District and 96% of all respondent laboratories reported isolating at least one MRSA isolate during the preceding year. These data are considered an underestimate of the time MRSA rate in the VA system due to the fact that many laboratories failed to follow key methodologic guidelines for optimal detection of MRSA. A positive correlation was found between MRSA isolation rate and several measures of hospital size and activity including total beds, total admissions, and total antimicrobial susceptibility tests performed. Geographic clustering of MRSA isolation was observed with distinct areas of very high and very low percentages of S aureus isolates reported as MRSA. The data suggest that the geographic distribution of MRSA within the VA system should be monitored closely for evidence of spread from areas with high-MRSA rates to areas of mid- or low-MRSA rates. Evidence of increased MRSA isolation within these areas may necessitate increased caution in patient referral and transfer patterns within the VA system.

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Prevalence and antimicrobial susceptibility of genital Mycoplasmas detected by Mycoplasma IST 2 from urogenital samples in Padua, Italy, between January 2014 and December 2015

Microbiologia Medica ◽

10.4081/mm.2017.6503 ◽

2017 ◽

Vol 32 (1) ◽

Cited By ~ 1

Author(s):

Andrea Bartolini ◽

Margherita Scapaticci ◽

Wassim Akkouche ◽

Caterina Boldrin ◽

Lucia Rossi

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Susceptibility ◽

Mycoplasma Hominis ◽

Population Surveillance ◽

Antimicrobial Resistance Profile ◽

High Prevalence ◽

Antimicrobial Susceptibility Tests ◽

Study Population ◽

Susceptibility Tests ◽

Genital Mycoplasmas

Background and aims. The aim of this study is to define the epidemiology and the antimicrobial resistance profile of Ureaplasma spp. and Mycoplasma hominis isolated from urogenital specimens of patients attending the Microbiology and Virology Unit of Padua between January 2014 and December 2015. Materials and methods. The analysis was carried out on a total of 10861 samples. Species identification and antimicrobial susceptibility tests were performed using bioMérieux Mycoplasma IST 2. Results. 2668 samples (24.6%) from 2043 patients were positive: 2466 samples positive for Ureaplasma spp. (1897 patients) and 8 samples positive for M. hominis (8 patients), while in 194 samples (138 patients) was detected a coinfection. As for antimicrobial susceptibility of Ureaplasma spp. we found a resistance (R+I) rate of 90.6% for ciprofloxacin, of 74,1% for ofloxacin, of 52.8% for azithromycin and of 47.0% for erythromycin. Conclusions. Our report shows a high prevalence of Ureaplasma spp. in the study population. Surveillance of antibiotic resistance is critical for an appropriate therapeutic approach, which must always be contextualized with patient’s symptomatology.

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DETECTION OF AMINOGLYCOSIDE AND QUINOLONE RESISTANCE GENES AND EVALUATION OF POLYMYXIN B SUSCEPTIBILITY PROFILE IN ACINETOBACTER BAUMANNII CLINICAL ISOLATES IN TEHRAN, IRAN DURING 2015-2016

Mediterranean Journal of Hematology and Infectious Diseases ◽

10.4084/mjhid.2018.044 ◽

2018 ◽

Vol 10 (1) ◽

pp. e2018044 ◽

Cited By ~ 5

Author(s):

Mohsen Heidary

Keyword(s):

Acinetobacter Baumannii ◽

Resistance Genes ◽

Antimicrobial Susceptibility ◽

Polymyxin B ◽

Quinolone Resistance ◽

Clinical Isolates ◽

Diffusion Method ◽

Clinical Samples ◽

Antimicrobial Susceptibility Tests ◽

Susceptibility Tests

ABSTRACTAcinetobacter baumannii is an important opportunistic pathogen, responsible for approximately 10% of all gram-negative nosocomial infection. The main aims of this study were to detect aminoglycoside and quinolone resistance genes among clinical isolates of A. baumannii and determine the antimicrobial susceptibility profiles. Current study was performed from February 2015 to April 2016, at two teaching hospitals. One-hundred A. baumannii isolates were collected from different clinical samples. Antimicrobial susceptibility tests were done by disk diffusion method according to CLSI guidelines. Detection of the qnrA, anrB, qnrS, aac(3)-IIa, and aac(6′)-Ib genes was done by PCR assay. The results of antibiotic susceptibility tests indicated that polymyxin B was the most effective drug against isolates of A. baumannii and the isolates were most resistant to cefepime (97%), ceftriaxone (95%), and amikacin (82%). The aac(3)-IIa, aac(6′)-Ib, and qnrA genes were found in 45%, 50%, and 50% of isolates, respectively. However, qnrB and qnrS genes could not be detected in any A. baumannii isolate.This study showed that there is a high level of resistance genes among clinical isolates of A. baumannii circulating in hospitals in Iran. This high prevalence rate highlights the necessity for establishing rapid diagnostic assays, more antimicrobial susceptibility tests, continuous antibiotic resistance monitoring.Keywords: Acinetobacter baumannii, Aminoglycoside, Quinolone, Iran

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Evaluation of Antimicrobial Resistance inStaphylococcus aureusIsolates by Years

Interdisciplinary Perspectives on Infectious Diseases ◽

10.1155/2016/9171395 ◽

2016 ◽

Vol 2016 ◽

pp. 1-4 ◽

Cited By ~ 4

Author(s):

Cennet Rağbetli ◽

Mehmet Parlak ◽

Yasemin Bayram ◽

Huseyin Guducuoglu ◽

Nesrin Ceylan

Keyword(s):

Antibiotic Resistance ◽

Antibiotic Susceptibility ◽

Methicillin Resistance ◽

Medical Center ◽

Automated System ◽

Clinical Samples ◽

Becton Dickinson ◽

Antibiotic Susceptibility Test ◽

Susceptibility Tests ◽

Resistance Rates

Objective. Recently, community and hospital-acquired infections withStaphylococcus aureushave increased and raised antibiotic resistant isolates. In this study, we aimed to evaluate the antibiotic resistance profile ofS. aureusisolates over several years in various clinical specimens from our hospital.Materials and Methods.S. aureusstrains from 2009 to 2014 were isolated from various clinical samples at Yuzuncu Yil University, Dursun Odabas Medical Center, Microbiology Laboratory, and their antibiotic susceptibility test results were retrospectively investigated. The isolates were identified by conventional methods, and antibiotic susceptibility tests were performed by the Phoenix (Becton Dickinson, USA) automated system method according to Clinical and Laboratory Standards Institute (CLSI) standards.Results. A total of 1,116S. aureusisolates were produced and methicillin-resistantS. aureus(MRSA) to 21% of allS. aureusisolates between 2009 and 2014. According to the results of susceptibility tests of all isolates ofS. aureus, they have been identified as sensitive to vancomycin, daptomycin, linezolid, and levofloxacin. While the resistance rates to nitrofurantoin, quinupristin-dalfopristin, and trimethoprim-sulfamethoxazole were determined as 0.3%, 2.4%, and 6%, respectively, resistance rates to penicillin, erythromycin, rifampicin, gentamicin, and clindamycin were determined as 100%, 18%, 14%, 14%, and 11%, respectively. The highest percentage of methicillin resistance was determined as 30% in 2009, and the resistance was determined to have decreased in subsequent years (20%, 16%, 13%, 19%, and 21%) (p<0.001).Conclusion. Currently, retrospective evaluations of causes of nosocomial infection should be done periodically. We think that any alteration of resistance over the years has to be identified, and all centers must determine their own resistance profiles, in order to guide empirical therapies. Reducing the rate of antibiotic resistance will contribute to reducing the cost of treatment.

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Diagnosis and Treatment of Human Salmonellosis in Addis Ababa City, Ethiopia

BioMed Research International ◽

10.1155/2018/6406405 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7

Author(s):

Legesse Garedew ◽

Semaria Solomon ◽

Yoseph Worku ◽

Hilina Worku ◽

Debela Gemeda ◽

...

Keyword(s):

Antimicrobial Susceptibility ◽

Addis Ababa ◽

Clinical Signs ◽

Diagnosis And Treatment ◽

Widal Test ◽

Predictive Values ◽

Blood Samples ◽

Antimicrobial Susceptibility Tests ◽

Stool Samples ◽

Susceptibility Tests

Background. Diagnosis using reliable tools and treatment followingin vitroantimicrobial susceptibility tests are critical to proper addressing of antibiotic-resistantSalmonellainfection.Methodology. A cross-sectional study was conducted to assess the practice of diagnosis and treatment of salmonellosis in Addis Ababa. Tube Widal test (for blood samples only), culture, biochemical and carbohydrate fermentation, serotyping, and antimicrobial susceptibility tests were employed for both blood and stool samples.Results. Of all the diseases listed in the diagnosis, nontyphoidal (n=72, 13.71%) and typhoidal (n=47, 8.95%) salmonellosis were the second and third common diseases. Among the 288 blood samples, almost half were positive for O, H, or both antigens. However, only 1 (0.68%) of the positive blood samples yieldedSalmonellaisolate during culture. The study demonstrated low specificity (0.68%) and positive predictive value (48.78%) of Widal test. Conversely, the test showed 100% sensitivity and negative predictive values.Salmonellaisolates were identified from 7 (7.07%) of 99 stool samples. Two-thirds of salmonellosis suspected patients received antibiotic treatment. However, only half of the confirmed salmonellosis patients were treated with appropriate antibiotics. All of the isolates were susceptible to ciprofloxacin and ceftriaxone but resistant to ampicillin.Conclusions. Majority of the patients who participated in this study were wrongly diagnosed using symptoms, clinical signs, and tube Widal test. Consequently, most of the patients received inappropriate treatment.

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Quality control limits for antimicrobial susceptibility tests of cefpirome

Clinical Microbiology and Infection ◽

10.1111/j.1469-0691.1999.tb00715.x ◽

1999 ◽

Vol 5 (12) ◽

pp. 771-773

Author(s):

Steven D. Brown ◽

Arthur L. Barry

Keyword(s):

Quality Control ◽

Antimicrobial Susceptibility ◽

Antimicrobial Susceptibility Tests ◽

Susceptibility Tests ◽

Control Limits

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Yersinia enterocolitica isolates from humans in California, 1968-1975

Journal of Clinical Microbiology ◽

10.1128/jcm.4.2.137-144.1976 ◽

1976 ◽

Vol 4 (2) ◽

pp. 137-144

Author(s):

M L Bissett

Keyword(s):

Yersinia Enterocolitica ◽

Antimicrobial Susceptibility ◽

Breast Abscess ◽

Biochemical Tests ◽

California Department ◽

Biochemical Characteristics ◽

Serotype O ◽

Department Of Health ◽

Antimicrobial Susceptibility Tests ◽

Susceptibility Tests

This paper reports on the serological and biochemical characteristics of 24 human isolates of Yersinia enterocolitica submitted to the California Department of Health from 1968 through 1975. Nine different serotypes were represented. The majority of strains were serotype O:8 (six strains) and serotype O:5 (five strains). Sources of the isolates included feces (12 cases), blood (3), sputum or throat (3), bile or bowel drainage (2), wounds (2), breast abscess (1), and skin abscess (1). Clinical histories indicated a number of different syndromes. Underlying medical conditions existed in 13 cases. Results of selected biochemical tests and antimicrobial susceptibility tests on the strains indicated grouping compatible with the O serotypes of the organisms.

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