scholarly journals Characterization of Methicillin-ResistantStaphylococcus aureusIsolates from Patients with Persistent or Recurrent Bacteremia

2014 ◽  
Vol 25 (2) ◽  
pp. 83-86 ◽  
Author(s):  
Henry Wong ◽  
Christine Watt ◽  
Sameer Elsayed ◽  
Michael John ◽  
Glen Johnson ◽  
...  

BACKGROUND: Methicillin-resistantStaphylococcus aureus(MRSA) bloodstream infections (BSI) are associated with considerable morbidity and mortality, especially with persistent (PB) or recurrent bacteremia (RB).OBJECTIVE: To determine the frequency of PB and RB in patients with MRSA BSI, and to characterize the isolates from these patients.METHODS: Surveillance for MRSA BSI was performed for one year in 13 Canadian hospitals. PB was defined as a positive blood culture that persisted for ≥7 days; RB was defined as the recurrence of a positive blood culture ≥14 days following a negative culture. Isolates were typed using pulsed-field gel electrophoresis (PFGE). Vancomycin susceptibility was determined using Etest.RESULTS: A total of 183 patients with MRSA BSI were identified; 14 (7.7%) had PB and five (2.7%) had RB. Ten (5.5%) patients were known to have infective endocarditis, and five of these patients had PB or RB. Initial and subsequent MRSA isolates from patients with PB and RB had the same PFGE type. There were no significant differences in the distribution of PFGE types in patients with PB or RB (37% CMRSA-2/USA100; 37% CMRSA-10/USA300) compared with that in other patients (56% CMRSA-2/USA100; 32% CMRSA-10/USA300). All isolates were susceptible to vancomycin, but patients with PB or RB were more likely to have initial isolates with vancomycin minimum inhibitory concentration = 2.0 μg/mL (26% versus 10%; P=0.06).CONCLUSIONS: Persistent or recurrent MRSA bacteremia occurred in 10.4% of patients with MRSA BSIs. Initial isolates from patients with persistent or recurrent MRSA BSIs were more likely to exhibit reduced susceptibility to vancomcyin, but were not associated with any genotype.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sandra Chamat-Hedemand ◽  
Niels Eske Bruun ◽  
Lauge Østergaard ◽  
Magnus Arpi ◽  
Emil Fosbøl ◽  
...  

Abstract Background Infective endocarditis (IE) is diagnosed in 7–8% of streptococcal bloodstream infections (BSIs), yet it is unclear when to perform transthoracic (TTE) and transoesophageal echocardiography (TOE) according to different streptococcal species. The aim of this sub-study was to propose a flowchart for the use of echocardiography in streptococcal BSIs. Methods In a population-based setup, we investigated all patients admitted with streptococcal BSIs and crosslinked data with nationwide registries to identify comorbidities and concomitant hospitalization with IE. Streptococcal species were divided in four groups based on the crude risk of being diagnosed with IE (low-risk < 3%, moderate-risk 3–10%, high-risk 10–30% and very high-risk > 30%). Based on number of positive blood culture (BC) bottles and IE risk factors (prosthetic valve, previous IE, native valve disease, and cardiac device), we further stratified cases according to probability of concomitant IE diagnosis to create a flowchart suggesting TTE plus TOE (IE > 10%), TTE (IE 3–10%), or “wait & see” (IE < 3%). Results We included 6393 cases with streptococcal BSIs (mean age 68.1 years [SD 16.2], 52.8% men). BSIs with low-risk streptococci (S. pneumoniae, S. pyogenes, S. intermedius) are not initially recommended echocardiography, unless they have ≥3 positive BC bottles and an IE risk factor. Moderate-risk streptococci (S. agalactiae, S. anginosus, S. constellatus, S. dysgalactiae, S. salivarius, S. thermophilus) are guided to “wait & see” strategy if they neither have a risk factor nor ≥3 positive BC bottles, while a TTE is recommended if they have either ≥3 positive BC bottles or a risk factor. Further, a TTE and TOE are recommended if they present with both. High-risk streptococci (S. mitis/oralis, S. parasanguinis, G. adiacens) are directed to a TTE if they neither have a risk factor nor ≥3 positive BC bottles, but to TTE and TOE if they have either ≥3 positive BC bottles or a risk factor. Very high-risk streptococci (S. gordonii, S. gallolyticus, S. mutans, S. sanguinis) are guided directly to TTE and TOE due to a high baseline IE prevalence. Conclusion In addition to the clinical picture, this flowchart based on streptococcal species, number of positive blood culture bottles, and risk factors, can help guide the use of echocardiography in streptococcal bloodstream infections. Since echocardiography results are not available the findings should be confirmed prospectively with the use of systematic echocardiography.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S47-S47
Author(s):  
Bryant M Froberg ◽  
Nicholas Torney

Abstract Background As many as 1 in 3 patients with bloodstream infections at community hospitals receive inappropriate empiric antimicrobial therapy. Studies have shown that the coupling of real-time intervention with rapid pathogen identification improves patient outcomes and decreases health-system costs at large, tertiary academic centers. The aim of this study was to assess if similar outcomes could be obtained with the implementation of real-time pharmacist intervention to rapid pathogen identification at two smaller, rural community hospitals. Methods This was a pre-post implementation study that occurred from September of 2019 to March 2020. This study included patients ≥18 years of age admitted with one positive blood culture. Patients were excluded if they were pregnant, had a polymicrobial blood culture, known culture prior to admission, hospice consulted prior to admission, expired prior to positive blood culture, or transferred to another hospital within 24 hours of a positive blood culture. Endpoints of patients prior to intervention were compared to patients post-implementation. The primary endpoint was time to optimal antimicrobial therapy. Secondary endpoints included time to effective antimicrobial therapy, in-hospital mortality, length of hospital stay, and overall cost of hospitalization. Results Of 212 patients screened, 88 patients were included with 44 patients in each group. Both groups were similar in terms of comorbidities, infection source, and causative microbial. No significant difference was seen in the mean time to optimal antimicrobial therapy (27.3±35.5 hr vs 19.4± 30 hr, p=0.265). Patients in the post-implementation group had a significantly higher mean hospitalization cost ($24,638.87± $11,080.91 vs $32,722.07±$13,076.73, p=0.013). There was no significant difference in time to effective antimicrobial therapy, in-hospital mortality, or length of hospital stay. Conclusion There were no between-group differences in the primary outcome of time to optimal therapy, with a higher mean hospitalization cost after implementation. These results suggest further antimicrobial stewardship interventions are needed, along with larger studies conducted in the community hospital settings. Disclosures All Authors: No reported disclosures


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S157-S157
Author(s):  
Sujeet Govindan ◽  
Luke Strnad

Abstract Background At our institution, we learned the frequency of blood cultures was sometimes being changed from “Once” to “Daily” without a defined number of days. We hypothesized this led to unnecessary blood cultures being performed. Methods Over a 3 month period from 12/6/2019-3/6/2020, we retrospectively evaluated the charts of patients who had a blood culture frequency changed to “Daily”. We evaluated if there was an initial positive blood culture within 48 hours of the “Daily” order being placed and the number of positive, negative, or “contaminant” sets of cultures drawn with the order. Contaminant blood cultures were defined as a contaminant species, present only once in the repeat cultures, and not present in initial positive cultures. Results 95 unique orders were placed with 406 sets of cultures drawn from 89 adults. ~20% of the time (17 orders) the order was placed without an initial positive blood culture. This led to 62 sets of cultures being drawn, only 1 of which came back positive. 78/95 orders had an initial positive blood culture. The most common initial organisms were Staphylococcus aureus (SA) (38), Candida sp (10), Enterobacterales sp (10), and coagulase negative staphylococci (7). 43/78 (55%) orders with an initial positive set had positive repeat cultures. SA (26) and Candida sp (8) were most common to have positive repeats. Central line associated bloodstream infections (CLABSI) were found in 5 of the orders and contaminant species were found in 4 of the orders. 54% of the patients who had a “Daily” order placed did not have positive repeat cultures. The majority of the cultures were drawn from Surgical (40 orders) and Medical (35 orders) services. Assuming that SA and Candida sp require 48 hours of negative blood cultures to document clearance and other species require 24 hours, it was estimated that 51% of the cultures drawn using the "Daily" frequency were unnecessary. Cost savings over a year of removing the "Daily" frequency would be ~&14,000. Data from "Daily" blood culture orders drawn at Oregon Health & Science University from 12/6/2019-3/6/2020 Conclusion Unnecessary blood cultures are drawn when the frequency of blood cultures is changed to "Daily". Repeat blood cultures had the greatest utility in bloodstream infections due to SA or Candida sp, and with CLABSI where the line is still in place. These results led to a stewardship intervention to change blood culture ordering at our institution. Disclosures All Authors: No reported disclosures


2011 ◽  
Vol 57 (6) ◽  
pp. 476-484 ◽  
Author(s):  
Xiao Xue Ma ◽  
Dan Dan Sun ◽  
Jian Hu ◽  
En Hua Wang ◽  
En Jie Luo

In the present study, we report on the reduced susceptibility to teicoplanin among clinical isolates of Staphylococcus haemolyticus in a hematology ward of a teaching hospital. The molecular characterization of 17 S. haemolyticus strains was performed using mec gene complex classification, pulsed-field gel electrophoresis analysis, and minimum inhibitory concentration examination. Pulsotype A strains carrying a class C2 mec gene complex were the most prevalent strains, at 64.7%. In vivo selection of stepwise increase in resistance to vancomycin and teicoplanin was observed in three S. haemolyticus strains serially isolated from a case patient. The results of the present study suggest the regional spread of certain S. haemolyticus clones with diminished susceptibility to glycopeptides, emphasizing the need for continuous monitoring of minimum inhibitory concentration levels of vancomycin and teicoplanin in S. haemolyticus strains, and the importance of infection control practices to prevent its transmission.


Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Jun-Feng Zhang ◽  
Ke Shang ◽  
Jong-Yeol Park ◽  
Yea-Jin Lee ◽  
Yu-Ri Choi ◽  
...  

Antimicrobial resistance and pulsed-field gel electrophoresis (PFGE) genotypes of collected S. enterica ser. Gallinarum isolates were investigated to examine the epidemiological relationship between field outbreak isolates of S. enterica ser. Gallinarum. Thirty S. enterica ser. Gallinarum isolates collected from poultry farms with FT outbreaks from 2013 to 2018 in South Korea were analyzed. All isolates were resistant to at least 3 of the 18 antimicrobials tested and exhibited an MDR phenotype. All isolates showed resistance to streptomycin, sulfisoxazole, and colistin. One isolate was resistant to 9 antimicrobials. The antimicrobial resistance profile, streptomycin-sulfisoxazole-colistin-nalidixic acid-ciprofloxacin-gentamicin (18/30, 60.0%), was the most prevalent. PFGE types were classified into 10 groups with a 100% correlation cutoff in dendrograms for 30 field isolates. The dominant PFGE types were 1 (8/30, 26.7%), 4 (7/30, 23.3%), and 9 (5/30, 16.7%). Interestingly some isolates collected from the same and different companies had the same PFGE type. We reported a high MDR rate in S. enterica ser. Gallinarum isolates. The present study highlights the occurrence of horizontal spread and cyclic contamination of MDR S. enterica ser. Gallinarum within the same company. Furthermore, we showed cross-contamination between different companies. The characterization of these isolates would be helpful in the development of prevention and control strategies for MDR S. enterica ser. Gallinarum infection in South Korea.


2013 ◽  
Vol 76 (2) ◽  
pp. 248-255 ◽  
Author(s):  
MEGUMI HASEGAWA ◽  
ERIKO IWABUCHI ◽  
SHIORI YAMAMOTO ◽  
HIDETAKE ESAKI ◽  
KAZUHIKO KOBAYASHI ◽  
...  

This study was conducted to determine the prevalence and characteristics of Listeria monocytogenes in bovine colostrum in Japan. We collected bovine colostrum samples from 210 dams from 21 dairy farms in Hokkaido prefecture (Japan) between March and June 2009. L. monocytogenes was detected in samples from 6 (28.6%) of the 21 farms. Of the 210 samples, 16 (7.6%) were positive for L. monocytogenes. We recovered 80 L. monocytogenes isolates; 44 (55%) isolates were classified as serotype 1/2b and 36 (45%) were classified as serotype 4b. The isolates were susceptible to penicillin, ampicillin, amoxicillin, gentamicin, kanamycin, streptomycin, erythromycin, vancomycin, tetracycline, chloramphenicol, ciprofloxacin, and trimethoprimsulfamethoxazole. Pulsed-field gel electrophoresis (PFGE) characterization of the 80 isolates revealed six PFGE types. Two PFGE types corresponded to human listeriosis cases. Most L. monocytogenes isolates possessed virulence-associated genes (actA, hly, iap, inlA, inlC, mpl, plcA, plcB, opuCA, prfA, and clpC). One PFGE type isolate possessed an epidemic clone II marker. Our findings suggest that isolates from bovine colostrum have the potential to cause human and animal listeriosis. This is the first study on the prevalence and characteristics of L. monocytogenes isolated from bovine colostrum obtained from dairy farms. Our results have important implications for improving public health and elucidating the epidemiology of L. monocytogenes in bovine colostrum.


2020 ◽  
Vol 75 (4) ◽  
pp. 968-978 ◽  
Author(s):  
Emma Jonasson ◽  
Erika Matuschek ◽  
Gunnar Kahlmeter

Abstract Objectives With increasing antimicrobial resistance, rapid antimicrobial susceptibility testing (RAST) becomes important, especially in patients with bloodstream infections. EUCAST decided to develop a standardized rapid method, based on EUCAST disc diffusion, to offer susceptibility reports within 4–8 h of a positive blood culture (BC). Methods BC bottles were spiked with clinical isolates (n = 332) of the seven most relevant sepsis pathogens with a variety of resistance mechanisms. RAST was performed directly from the bottle and zones read after 4, 6 and 8 h. Several variables were investigated, including the effect of using different BC bottles and of a 0–18 h delay between a positive signal and the performance of RAST. Results For five species, most inhibition zones could be read after 4 h. The proportion of results that could be interpreted increased from 75% at 4 h to 84% after 8 h. Categorical agreement against the reference method was good, with error rates of false susceptibility of 0.2%, 0.2% and 0.2% at 4, 6 and 8 h and false resistance of 1.2%, 0.2% and 0.1% at 4, 6 and 8 h, respectively. Conclusions With the EUCAST RAST method, reliable AST results can be delivered within 4–8 h of positivity of BC bottles for seven important bloodstream infection pathogens. To reduce the occurrence of errors and to absorb the variability caused by using a non-standardized inoculum, material from different manufacturers and workflow-related delays, we have introduced an area in which interpretation is not permitted, the Area of Technical Uncertainty.


2018 ◽  
Vol 57 (2) ◽  
Author(s):  
Te-Din Huang ◽  
Ekaterina Melnik ◽  
Pierre Bogaerts ◽  
Stephanie Evrard ◽  
Youri Glupczynski

ABSTRACT Rapid identification and susceptibility testing results are of importance for the early appropriate therapy of bloodstream infections. The ePlex (GenMark Diagnostics) blood culture identification (BCID) panels are fully automated PCR-based assays designed to identify Gram-positive and Gram-negative bacteria, fungi, and bacterial resistance genes within 1.5 h from positive blood culture. Consecutive non-duplicate positive blood culture episodes were tested by the ePlex system prospectively. The choice of panel(s) (Gram-positive, Gram-negative, and/or fungal pathogens) was defined by Gram-stained microscopy of blood culture-positive bottles (BacT/Alert; bioMérieux). Results with the ePlex panels were compared to the identification results obtained by standard culture-based workflow. In total, 216 positive blood culture episodes were evaluable, yielding 263 identification results. The sensitivity/positive predictive value for detection by the ePlex panels of targeted cultured isolates were 97% and 99% for the Gram-positive panel and 99% and 96% for the Gram-negative panel, resulting in overall agreement rates of 96% and 94% for the Gram-positive and Gram-negative panel, respectively. All 26 samples with targeted resistance results were correctly detected by the ePlex panels. The ePlex panels provided highly accurate results and proved to be an excellent diagnostic tool for the rapid identification of pathogens causing bloodstream infections. The short time to results may be of added value for optimizing the clinical management of patients with sepsis.


2014 ◽  
Vol 139 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Eric Salazar ◽  
Mukul Divatia ◽  
Patricia L. Cernoch ◽  
Randall J. Olsen ◽  
S. Wesley Long ◽  
...  

Context Timely processing of blood cultures with positive results, including Gram staining and notification of clinicians, is a critical function of the clinical microbiology laboratory. Analysis of processing time in our laboratory revealed opportunities to enhance workflow efficiency. We found that the average time from positive blood culture result to removal of the bottle for processing (positive-to-removal [PR] time) was inadequate for our rapid pathogen identification program. Objective To determine whether increased vigilance about PR time and prioritization of laboratory resources would decrease PR time and total processing time. Design We performed a retrospective analysis of blood culture PR time 7 months before and 7 months after an in-service meeting during which the importance of PR time was emphasized, and corrective measures were implemented. Results Before the in-service meeting, the average PR time for 5057 samples was 38 minutes, with an aggregate time of 192 251 minutes. Unexpectedly, we discovered that only 51.8% (2617 of 5057) of the positive blood cultures were removed in less than 10 minutes. After the in-service meeting, for 5293 samples, the average PR time improved to 8 minutes, the aggregate time improved to 44 630 minutes, and 84.5% (4470 of 5293) of the positive blood cultures were removed in less than 10 minutes. These improvements reduced the time to telephone notification of the Gram stain results to a caregiver by 46.7% (from 105 minutes to 56 minutes). Conclusions Increased awareness of barriers to rapid pathogen identification and interventions for improving performance time significantly enhanced care of patients with bloodstream infections.


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