BACKGROUND: Recovering pathogenic bacteria and yeast from pediatric blood cultures and reliably distinguishing between pathogens and contaminants are likely to be improved by increasing the volume of blood submitted to microbiology laboratories for culturing beyond the low volumes that have historically have been used. The primary aim of this study was to assess whether the pathogen recovery rate would increase after implementation of a weight-based algorithm for determining the intended volume of blood submitted for culturing. Secondary aims were to: 1) evaluate the effects of the algorithm implementation on the blood culture contamination rate; 2) determine whether pathogens might be found more often than contaminants in several as opposed to single bottles when more than one bottle is submitted; and 3) describe the microbiological findings for pathogens and contaminants in blood cultures by applying a clinical validation of true blood culture positivity.
METHODS: A pre-post comparison of positivity and contamination rates after increasing the theoretical blood volume and number of blood culture bottles was performed, on the basis of a clinical validation of blood culture findings as pathogens vs contaminants.
RESULTS: We examined 5327 blood cultures, including 186 with growth (123 true positives and 63 contaminated). The rate of true positive blood cultures significantly increased from 1.6% (42/2553) pre to 2.9% (81/2774, p = .002) post intervention. The rate of contaminated blood cultures did not change significantly during the study period (1.4% [35/2553] pre vs 1.0% [28/2774], p = .222) post intervention), but the proportion of contaminated cultures among all positive cultures decreased from 45% (35/77) pre to 26% (28/109, p = .005) post intervention. A microorganism that grew in a single bottle was considered a contaminant in 35% (8/23) of cases, whereas a microorganism that grew in at least two bottles was considered a contaminant in 2% (1/49, p < .001) of cases. According to common classification criteria relying primarily on the identity of the microorganism, 14% (17/123) of the recovered pathogens would otherwise have been classified as contaminants.
CONCLUSIONS: Implementation of a weight-based algorithm to determine the volume and number of blood cultures in pediatric patients is associated with an increase in the pathogen recovery rate.

BACKGROUND: Contamination rates reported in the literature for patient-ready flexible endoscopes vary from 0.4% to 49%. Unfortunately, the comparison and interpretation of these results is almost impossible since several factors including sampling and culturing methods, target levels for contamination, or definition of indicator micro-organisms vary widely from one study to the other.
OBJECTIVE: To compare the efficacy of six duodenoscope sampling and culturing methods by means of extraction efficacy comparison, while at the same time identifying key parameters that provide optimal microbial recovery.
METHODS: The duodenoscope sample extraction efficacy of each method was assessed using the repetitive recovery method described in ISO 11737-1: 2018.
RESULTS: Mean overall bioburden extraction efficacy varied from 1% for the Australian method to 39% for the French one. The lowest endoscope sample extraction efficacy was associated with the absence of any neutralizer, friction, or tensioactive agent, and when only a small portion of the sampling solution collected was inoculated on to culture media. The efficacy of the sampling and culturing methods also varied according to the nature of micro-organisms present in the endoscope, and the time between sampling and culturing.
CONCLUSIONS: This study supports the need for a harmonized and standardized sampling and culturing method for flexible endoscopes.

Could the microbial contamination rate of oocytes and embryos in conventional IVF cycles be further reduced by modifying the handling procedures of cumulus-oocyte complexes (COC)?
Two modifications were applied to COC handling procedures. First, a mark was made on the outer wall of the 10-cm Petri dish to indicate the site from which the follicular fluid was poured out during the oocyte retrieval process (modified handling 1) since May 2018. Second, a modified way of pipetting during denuding (modified handling 2) has been adopted since June 2019. The microbial contamination rates before and after each modification were compared. The clinic outcomes of patients with a history or at a high risk of microbial contamination were reported after incorporating the two modifications of COC handling.
After the first modification was implemented, the contamination rate was remarkably reduced from 0.37% (9/2436) to 0.18% (2/1089). After adding the second modification, no new contamination occurred in the subsequent 3178 conventional IVF cycles (P = 0.001). Moreover, no contamination was noted in patients with a history of microbial contamination or persistent candidal vaginitis during conventional IVF after modifications of COC handling.
Modifying the handling procedures of COC can minimize the microbial contamination rate in conventional IVF cycles. Contamination risk directly derived from the urogenital tracts might be less likely than what we thought to be with current IVF techniques.

The importance of blood culture has been widely recognized, and there is a need for monitoring to evaluate the accuracy of blood culture that reflects domestic healthcare systems. In this study, we assessed 6-year trends in blood culture quality assurance data. The Japan Infection Prevention and Control Conference for National and Public University Hospitals conducted yearly blood culture surveillance at 52 national public university hospitals from 2015 to 2020. Statistical analysis showed that comparison with the previous year showed significant differences in the number of blood cultures per 1000 patient-days in all years. The number of blood cultures per 1000 admissions was not significantly different in 2017 and 2018, but significant differences were shown in all other years. The multiple blood culture set rate was significantly different between non-pediatric inpatients and outpatients but not between pediatric inpatients and outpatients. The contamination rate did not differ significantly. For all parameters, significant differences were found when comparing 2015 and 2020. Our survey showed that although the sample number improved over time, even the most recent values for 2020 were lower than Cumitech\'s targets. It is difficult to assess whether these sample numbers are appropriate because target values have not been set for the various types of hospitals in Japan. Surveillance is a useful tool for monitoring quality assurance for blood culture. All parameters improved over the 6-year period, but it is necessary to establish a benchmark for evaluating optimization. We will continue to monitor quality assurance and work on setting benchmarks.

Blood cultures should be collected within an hour in the setting of sepsis/septic shock. The contamination rate should be below 3%. Worldwide reports have described an increase in blood contamination rates during the COVID-19 pandemic. We performed a retrospective analysis of the blood cultures collected during a 10-month period (March−December 2020) at NIID “Prof. Dr. Matei Balș”. The results were compared with data from the pre-pandemic period (March−December 2016) and with the existing data in the literature. During the pandemic, there was a significant decrease in the number of blood cultures collected (1274 blood cultures in 2020 vs. 5399 in 2016). The contamination rate was higher in 2020 (11.7%) compared to 2016 (8.2%), p < 0.001. The rate of infectious episodes in which the etiological agent was identified was constant: 11% in 2020 versus 11.9% in 2016, p = 0.479, but there were fewer invasive bacterial/fungal infections: 0.95/1000 patient days in 2020 vs. 2.39/1000 patient days in 2016, p < 0.001. We observed a change in the species distribution. The Gram-negative isolate’s proportion increased from 50.6% to 63.1% and the gram-positive isolate’s proportion decreased from 31.8% to 19%. Collection of a low number of blood cultures and a high contamination rate was identified in our clinic. In order to improve the usefulness of blood cultures as a diagnostic method, at least two sets should be collected in aseptic conditions.

暂无摘要。

UNASSIGNED: The objectives of this study were to determine the prevalence of microbial contamination of multi-user preserved ophthalmic drops (POD) in Ophthalmology Outpatient Clinic (OOC), to compare the rate of contamination between the dropper tip and the residual contents in the bottle, and to identify the contaminating organisms.
UNASSIGNED: This was an observational cross-sectional study using a convenience sampling method conducted in the OOC of Universiti Kebangsaan Malaysia Medical Center, Malaysia. The samples of POD bottles were divided into groups obtained after 14 days (T14) and after 30 days (T30) of use. The contamination rate at the dropper tip and in the residual contents was determined and the contaminating organisms were identified.
UNASSIGNED: A total of 140 of 149 extended-use POD bottles were included. The prevalence of contamination was 30%. There was a statistically significant difference in the rate of contamination between samples T14 and T30 (19% and 11%, respectively; p=0.046). Proparacaine and tropicamide showed higher contamination rates in the T14 samples (p=0.027 and p=0.497, respectively) than in the T30 samples. The site of contamination was higher at the dropper tip than in the residual contents (p>0.05). Coagulase-negative Staphylococcus species were the most frequently identified contaminants (89%).
UNASSIGNED: The dropper tip was more contaminated than the residual contents, and coagulase-negative Staphylococcus species, which are common commensal flora of the ocular conjunctiva and skin, were the most frequently identified organisms.

BACKGROUND: Various disinfectants, such as povidone iodine (PVI)1, alcohol preparations, and chlorhexidine gluconate ethanol (CHG-ALC), are used for disinfection prior to blood sampling for culture.
METHODS: This retrospective cohort study compared the usefulness and effectiveness of CHG-ALC and PVI in pediatric venipuncture. We applied 0.5% w/v CHG-ALC or 10% PVI as an antiseptic for phlebotomies on pediatric outpatients and inpatients with suspected bacterial infection between November 2017 and April 2019. We conducted logistic regression analysis to define the differences associated with the choice of disinfectant, collection site, and the staff member collecting the blood sample (explanatory variables) and the presence of contamination (objective variable). Based on these results, we performed propensity score matching.
RESULTS: The total number of specimens was 1460. The propensity score matching indicated that CHG-ALC reduced the incidence of blood culture contamination more effectively than PVI (0.4%, 2/479 cultures versus 2.5%, 12/479 cultures; relative risk, 0.163 [95% confidence interval, 0.036 to 0.733]; P = 0.012). There were no differences in the contamination rates between cultures of blood drawn from a vascular catheter and those of blood obtained percutaneously. Higher contamination rates were found when junior residents performed the venipuncture.
CONCLUSIONS: Compared with PVI, CHG-ALC dries rapidly with no pigmentation and has a long-lasting antiseptic effect. Overall, CHG-ALC skin preparations were more efficacious than the PVI preparations for blood sampling in children.

BACKGROUND: Tuberculosis (TB) is a major public health problem worldwide. Contamination rate and poor recovery of Mycobacterium tuberculosis complex (MTBC) in MGIT960 culture may affect the early diagnosis of TB. Evidence is needed to determine the factors associated with contamination rates and MTBC recovery in MGIT960. Hence, we undertook this study to compare the factors influencing MTBC culture positivity and contamination rates in MGIT960 in patients with Pulmonary tuberculosis (PTB).
METHODS: A total of 849 sputum samples from newly diagnosed smear-positive TB cases enrolled into the Regional Prospective Observational Research for Tuberculosis India cohort between May 2014 to March 2017 were analyzed. Samples were inoculated into MGIT960 and positive cultures were examined for the presence of MTBC by immunochromatographic test for detection of MPT64 antigen.
RESULTS: Of the 849 cases, 811 (95.5%) were culture positive for MTBC, 23 (2.7%) were culture negative and 15 (1.8%) were contaminated. Salivary sputum showed significantly less culture yield compared to mucopurulent/blood stained samples (p = 0.021). Sputum from individuals <20 or ≥60 years showed lower culture yield of 93.9%, compared to those aged 20-59years (98.2%) (p = 0.002). Based on smear grading, culture isolation of MTBC by MGIT960 was 86.1%, 93.6% and 99.5% for negative, scanty and positive (1+/2+/3+) samples, respectively (p ≤ 0.0001). Sputum from HIV negative patients showed higher culture yield, compared to HIV positive patients (p ≤ 0.0001). Chest X-Ray revealed that patient with cavity showed higher culture isolation of MTBC compared to patients without cavity (p = 0.035). Contamination rates were higher in smear negatives (6.0%), compared to scanty (2.1%) and smear positives (1.1%) (p = 0.007). However, delay in transport of the specimen to the laboratory was the only independent factor significantly associated with increase in culture contamination.
CONCLUSIONS: Our results highlight that extremes of age, smear negativity, HIV infection, sputum quality and cavitation significantly influence the culture yield of MTBC, whereas transport duration and smear grading affected the contamination rates in MGIT960. Hence, addressing these factors may improve the diagnostic performance of MGIT960.

OBJECTIVE: To evaluate the microorganism detection and contamination rate of donor eyes.
METHODS: Retrospective study.
METHODS: In this retrospective study, we reviewed all donor cornea data collected from Kyoto Prefectural University of Medicine (KPUM) Eye Bank, Kyoto, Japan from April 2015 to June 2018, including microbiologic data obtained from conjunctival swabs and preservation medium and findings of postoperative infection from the medical records.
RESULTS: During the study period, 77 eyes from 44 deceased individuals (mean age at time of death: 75 ± 17.3 years [range, 30-102 years]) were donated to the KPUM Eye Bank after being harvested using standard safety precautions and disinfection procedures. In 49 of the 77 eyes (63.6%), the conjunctival-swab culture revealed microorganisms, with the 3 most commonly detected being methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-sensitive S aureus (MSSA), and methicillin-resistant S aureus (MRSA). The data revealed positive microorganism detection in only 4 (5.2%) of the 77 donor-cornea storage-medium cultures. Positive microorganism detection was found in all the age groups, with no statistical difference between the groups (P > .05). In the eyes enucleated ≥ 2.5 h postmortem, a higher positive microorganism detection occurred (P = .03). During the postoperative follow-up period, there was no record of corneal infection.
CONCLUSIONS: The preenucleation conjunctival-swab-culture findings revealed that the rate of positive microorganism detection was similar for advanced-age and younger-age donors and that a shorter elapsed time from donor death to postmortem enucleation resulted in less donor-microorganism contamination.