Surveillance Swabs Research Articles

The Role of Healthcare Worker-Mediated Contact Networks in the Transmission of Vancomycin-Resistant Enterococci.

BackgroundUser- and time-stamped data from hospital electronic health records (EHRs) present opportunities to evaluate how healthcare worker (HCW)-mediated contact networks impact transmission of multidrug-resistant pathogens, such as vancomycin-resistant enterococci (VRE).MethodsThis is a retrospective analysis of incident acquisitions of VRE between July 1, 2016 and June 30, 2018. Clinical and demographic patient data were extracted from the hospital EHR system, including all recorded HCW contacts with patients. Contacts by an HCW with 2 different patients within 1 hour was considered a “connection”. Incident VRE acquisition was determined by positive clinical or surveillance cultures collected ≥72 hours after a negative surveillance culture.ResultsThere were 2952 hospitalizations by 2364 patients who had ≥2 VRE surveillance swabs, 112 (4.7%) patients of which had incident nosocomial acquisitions. Patients had a median of 24 (interquartile range [IQR], 18–33) recorded HCW contacts per day, 9 (IQR, 5–16) of which, or approximately 40%, were connections that occurred <1 hour after another patient contact. Patients that acquired VRE had a higher average number of daily connections to VRE-positive patients (3.1 [standard deviation {SD}, 2.4] versus 2.0 [SD, 2.1]). Controlling for other risk factors, connection to a VRE-positive patient was associated with increased odds of acquiring VRE (odds ratio, 1.64; 95% confidence interval, 1.39–1.92).ConclusionsWe demonstrated that EHR data can be used to quantify the impact of HCW-mediated patient connections on transmission of VRE in the hospital. Defining incident acquisition risk of multidrug-resistant organisms through HCWs connections from EHR data in real-time may aid implementation and evaluation of interventions to contain their spread.

577. The Role of Healthcare Worker-Mediated Contact Networks in the Transmission of Vancomycin-Resistant Enterococci

BackgroundHealthcare workers (HCWs) commonly contact multiple patients daily and serve as an important vector for transmission of pathogens such as vancomycin-resistant enterococci (VRE). Characterizing the HCW-patient network is difficult, which limits understanding of the role of HCWs in the horizontal transmission of pathogens. Electronic health records (EHR) present an opportunity to generate HCW-mediated contact networks and evaluate their impact on transmission.MethodsRetrospective analysis of patients (PT) admitted to a medical intensive care unit and solid-organ transplant unit between July 2016 and June 2017. Clinical and demographic information, including VRE surveillance swab outcomes, were extracted from the hospital EHR system. PT-HCW-PT connections were defined as HCW contacts with a patient within an hour of another patient. Multi-variable logistic regression was used to analyze factors associated with unit-acquired VRE colonization incidence.ResultsA total of 2,336 patients had a recorded interaction with 4,956 unique HCWs. 146 patients were colonized with VRE on unit-admission, and 29 patients had unit-acquired VRE colonization. HCWs had contact with ~2 (range: 1–23) patients a day and ~6 (range: 1–58) contacts with patients per day (Figure 1), though rates varied by HCW-type. Patients were contacted by ~7 different HCWs resulting in ~28 contacts per day, with nurses being the most common (Figure 2). This resulted in approximately 10 PT-HCW-PT connections per day (range: 1–33) to an average of 3 other patients. After adjusting for known VRE acquisition risk factors, HCW connections to other patients with VRE significantly increased the risk of VRE acquisition (odds ratio = 1.32; 95% CI: 1.20–1.44; Table 1).ConclusionUnderstanding how HCWs connect patients can elucidate how pathogens, such as VRE, spread in the hospital. We demonstrated how EHR data can inform how HCWs connect patients to spread HAIs and the impact of those connections on the spread of VRE. Though EHR data have limitations, as certain activities and contacts are not logged into the system, they provide a scalable and generalizable source for understanding how patients are connected and can be utilized to reduce the spread of nosocomial infections. Disclosures All authors: No reported disclosures.

464. Fecal Staphylococcus aureus in the Neonatal Intensive Care Unit

Background Staphylococcus aureus colonization in infants in the neonatal intensive care unit (NICU) often leads to repeated infections and severe disease. Methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) infections are major causes of NICU outbreaks. Current national practice in NICUs utilizes nare swab surveillance for S. aureus. We hypothesize that infants colonized in the stool with S. aureus may go unrecognized particularly when nare swab negative, allowing for a transmission reservoir. While it is unclear why some S. aureus nare carriers are also stool colonized, isolates tend to have clonality. A true prevalence of S. aureus fecal carriage is not well understood and variable.MethodsAvailable stool samples were prospectively collected from 42 of 55 infants admitted in a level IV NICU on a single day, per Cincinnati Children’s institutional review board approval. Nare swab results were obtained from electronic medical records. DNA was isolated from stool and shotgun metagenomic sequencing was performed via Hiseq Illuminex 2500. The presence of S. aureus and MRSA were defined as having >100 sequencing reads and a mecA DNA read fraction ratio >40 per stool sample, respectively.ResultsOf the 42 stool samples sequenced, 33 were S. aureus (15 MSSA, 18 MRSA) positive. All infants with nare positive MSSA (n = 9) were colonized in the stool with a 93% and 100% sensitivity and specificity, respectively. While infants with nare positive MRSA (n = 10) were stool colonized with 100% and 83% sensitivity and specificity, respectively. Three nare positive infants with MRSA had S.a. in the stool but lacked the presence of mecA. When comparing clinical nare swabs to stool metagenomic surveillance, sensitivities were 60% for MSSA and 56% for MRSA.ConclusionInfant colonization of S. aureus in the NICU remains a major problem despite current national surveillance and isolation practices. We found that nare swab surveillance for S. aureus in infants significantly underestimated colonization rates when compared with shotgun metagenomics of stool. These results suggest that nare swabs alone may not have adequate sensitivity and the implementation of stool surveillance should be considered to augment current practices. Future study is necessary to understand how the S. aureus stool reservoir contributes to transmissionDisclosures All authors: No reported disclosures.

The relation between positive screening results and MRSA infections in burn patients

IntroductionMethicillin-resistant Staphylococcus aureus (MRSA) is a key pathogen in burn patients. Several factors put them at increased risk of MRSA infection: partial loss of the skin barrier, the immune-compromising effects of burns, prolonged hospital stays, and invasive procedures. This study aims to find the relation between MRSA screening swab cultures taken within 48 h of admission, weekly surveillance cultures, and MRSA infection secondary to colonization. MethodsThe data of all burns patients admitted to the referral centre for burns from 2012 to 2016 were reviewed. MRSA cultures taken at admission and on weekly surveillance screening, including nasal, perianal, and wound swabs, were reviewed. To determine associations between MRSA colonization and infection rates, both MRSA-positive and MRSA-negative swab cultures were included in the analysis. Several risk factors were considered: age, gender, ethnicity, %TBSA, BAUX index, inhalational injury, ICU admission and days, need for ventilator support and days, length of stay (LOS) in hospital, and complications. Univariate and multiple logistic regression analyses were used to predict correlations between positive swab cultures and risk factors. ResultsData from 396 patients were reviewed. The median age at admission for the burn patients was 46 (IQR: 31–59) years. On admission, 2.5% of patients were MRSA positive, whereas 17.9% were found to be MRSA positive on weekly surveillance screening. At surveillance, 60.6% developed an infection secondary to MRSA colonization. An MRSA infection was not identified for any patient who did not have at least one positive admission or surveillance swab. A statistically significant association was found between any positive swab and MRSA infection (P < 0.001).The median number of complications reported in the MRSA-positive group was 2 (IQR: 1–3) versus 0 (IQR: 0–1) in the MRSA-negative group and the median length of hospital stay in the MRSA-positive group was 34.5 (IQR: 20.25–56.25) days versus 7 (IQR: 3–16) days in the MRSA-negative group (P < 0.001). ConclusionNosocomial MRSA colonization rates are high, and patients incurring infections experience a greater than average LOS in hospital and complications. Over 60% of patients who had a positive swab culture at surveillance developed an infection, whereas, no patient with a negative MRSA swab status developed an infection. Hence, pragmatic prevention strategies have to be implemented.

Studying Changes to Burn Wound Flora Over Time as an Opportunity for Antimicrobial Stewardship

Background Empiric antimicrobial selection for burn injury infection is of paramount importance owing to high rates of morbidity and mortality. By studying the time-related burn wound flora of our patient population, we developed an institutional syndrome-specific algorithm for the appropriate selection of empiric antimicrobial agents. Methods During the study period of January 1, 2016, through December 31, 2016, all patients with greater than or equal to 5% total body surface area burn injuries were included for analysis. Culture data from surveillance swabs and operative tissue specimens were reviewed, as it related to time after initial burn injury. Antimicrobial prescription was evaluated when used for a suspected burn injury infection. Results Isolation of gram-positive organisms predominated the 31 tissue cultures taken during days 1 to 4 postburn injury. A total of 18 (58%) grew a gram-positive organism, and only 2 (6%) grew a gram-negative rod. After 5 days, we saw a distinct change in microbial growth of the 23 tissue cultures taken, as 11 (48%) grew a gram-positive organism, 12 (52%) grew a gram-negative rod, and 9 (39%) grew Candida species. Even though Pseudomonas species was not isolated until at least 5 days postburn injury, the majority (71%) of antimicrobial prescriptions during the first 4 days after burn injury included an antipseudomonal agent. Conclusions These findings of time-related burn wound flora changes along with inappropriate antibiotic prescription led to the development of our institutional syndrome-specific algorithm for the appropriate selection of empiric antimicrobial agents.

Clinical Value of Screening Peritoneal Dialysis Patients for Bacterial Colonization or Contamination.

The adoption of the International Society for Peritoneal Dialysis guideline of using mupirocin ointment has been limited by fear of developing mupirocin-resistant organisms. We performed a surveillance program of a large peritoneal dialysis (PD) unit. We performed 1,175 surveillance swabs from anterior nares, PD catheter exit site, groin, and axilla, from 240 patients. The mean interval between swabs was 3.3 months. Colonization by Staphylococcus aureus (S. aureus) or Pseudomonas species was 9.5% and 10.9%, respectively. Despite adopting a universal policy of applying mupirocin to PD catheter exit sites in 2001, no instances of mupirocin-resistant S. aureus were identified. Moreover, patients who grew S. aureus from surveillance swabs did not experience higher peritonitis rates than those with "no growth." This was in contrast to patients who grew Pseudomonas or enteric organisms. There were no differences in patient demographics for those who grew S. aureus, Pseudomonas, or enteric organisms (compared with "no-growth" patients). Our results suggest that the application of mupirocin ointment appeared to minimize peritonitis of patients colonized with S. aureus. The use of mupirocin in this patient cohort has not led to mupirocin resistance. The increased peritonitis rate of patients who grew Pseudomonas or enteric organisms is of interest. We propose that greater attention to hygiene and catheter care in these patients is warranted. The increasing use of paid healthcare workers attending patients daily to help perform PD (assisted PD) gives an opportunity for us to address these wider issues.

1259. The Local Hospital Milieu and Healthcare-Associated VRE Acquisition

BackgroundThe relationship between the local hospital environment and VRE acquisition is not fully understood. The objective of this study was to identify risk factors for healthcare-associated VRE acquisition related to the local hospital milieu.MethodsThis retrospective cohort study included patients admitted to six ICUs at an academic medical center from January 1, 2012 to December 31, 2016 with negative rectal VRE cultures on admission. VRE acquisition was defined as a positive subsequent surveillance swab performed at any time after the initial negative surveillance swab during the index hospitalization. VRE colonization pressure was defined to encapsulate the circulating VRE burden during the at-risk patient’s ICU stay (patient-days of VRE exposure based on concurrently colonized patients on the unit, divided by time at risk). VRE importation pressure was defined to encapsulate the VRE burden at the time of ICU admission (patient-days of VRE exposure on the unit during the preceding 30 days, divided by total patient-days). Multivariable Cox proportional hazards modeling was used, with patients followed until VRE acquisition, death, or for up to 30 days.ResultsThere were 161 patients who acquired VRE among 8,485 patients with negative VRE cultures upon admission, including 1,131 patients who had repeat VRE cultures during the index hospitalization. On univariate analysis, patients with VRE acquisition were more likely to have received vancomycin, have had a neighboring patient who received vancomycin, have high VRE importation pressure, or have high VRE colonization pressure. On multivariable analysis, among these factors only high VRE colonization pressure was an independent predictor of VRE acquisition (aHR 1.79, 95% CI 1.19–2.70).ConclusionVRE colonization pressure was the most important risk factor for healthcare-associated VRE acquisition in this ICU population, regardless of VRE importation pressure or local use of vancomycin. Interventions seeking to reduce healthcare-associated VRE acquisition may wish to focus on ways to minimize transmission of VRE between patients with known VRE and the local hospital environment.Disclosures All authors: No reported disclosures.

Design and validation of a universal influenza virus enrichment probe set and its utility in deep sequence analysis of primary cloacal swab surveillance samples of wild birds

Influenza virus infections in humans and animals are major public health concerns. In the current study, a set of universal influenza enrichment probes was developed to increase the sensitivity of sequence-based virus detection and characterization for all influenza viruses. This universal influenza enrichment probe set contains 46,953 120nt RNA biotin-labeled probes designed based on all available influenza viral sequences and it can be used to enrich for influenza sequences without prior knowledge of type or subtype. Marked enrichment was demonstrated in influenza A/H1N1, influenza B, and H1-to-H16 hemagglutinin plasmids spiked into human DNA and in cultured influenza A/H2N1 virus. Furthermore, enrichment effects and mixed influenza A virus infections were revealed in wild bird cloacal swab samples. Therefore, this universal influenza virus enrichment probe system can capture and enrich influenza viral sequences selectively and effectively in different samples, especially ones with degraded RNA or containing low amount of influenza RNA.

The local hospital milieu and healthcare-associated vancomycin-resistant enterococcus acquisition

Vancomycin-resistant enterococcus (VRE) causes 4% of all healthcare-associated infections in the USA. The process by which the local hospital milieu contributes to VRE acquisition is not fully understood. To determine the importance of specific factors within the local hospital environment for healthcare-associated VRE acquisition. This retrospective cohort study included patients admitted to six intensive care units at an academic medical centre from January 2012 to December 2016 with negative rectal VRE cultures on admission. VRE acquisition was defined as a positive surveillance swab performed at any time after the initial negative swab during the index hospitalization. The exposures of interest were VRE colonization pressure, VRE importation pressure, and use of vancomycin. Multivariable Cox proportional hazards modelling was performed, with patients followed until VRE acquisition, death, or for up to 30 days. Of 8485 patients who were initially VRE negative, 161 patients acquired VRE. On univariate analysis, patients with VRE acquisition were more likely to have received vancomycin, to have had a neighbouring patient who received vancomycin, to have high VRE importation pressure, or to have high VRE colonization pressure. On multivariable analysis, only high VRE colonization pressure was an independent predictor of VRE acquisition (adjusted hazard ratio: 1.79; 95% confidence interval: 1.19-2.70). VRE colonization pressure was the most important risk factor for healthcare-associated VRE acquisition, regardless of VRE importation pressure. Interventions seeking to reduce VRE acquisition should focus on minimizing transmission between patients with known VRE and the local hospital environment.

Pathogen colonization of the gastrointestinal microbiome at intensive care unit admission and risk for subsequent death or infection.

Loss of colonization resistance within the gastrointestinal microbiome facilitates the expansion of pathogens and has been associated with death and infection in select populations. We tested whether gut microbiome features at the time of intensive care unit (ICU) admission predict death or infection. This was a prospective cohort study of medical ICU adults. Rectal surveillance swabs were performed at admission, selectively cultured for vancomycin-resistant Enterococcus (VRE), and assessed using 16S rRNA gene sequencing. Patients were followed for 30days for death or culture-proven bacterial infection. Of 301 patients, 123 (41%) developed culture-proven infections and 76 (25%) died. Fecal biodiversity (Shannon index) did not differ based on death or infection (p = 0.49). The presence of specific pathogens at ICU admission was associated with subsequent infection with the same organism for Escherichia coli, Pseudomonas spp., Klebsiella spp., and Clostridium difficile, and VRE at admission was associated with subsequent Enterococcus infection. In a multivariable model adjusting for severity of illness, VRE colonization and Enterococcus domination (≥ 30% 16S reads) were both associated with death or all-cause infection (aHR 1.46, 95% CI 1.06-2.00 and aHR 1.47, 95% CI 1.00-2.19, respectively); among patients without VRE colonization, Enterococcus domination was associated with excess risk of death or infection (aHR 2.13, 95% CI 1.06-4.29). Enterococcus status at ICU admission was associated with risk for death or all-cause infection, and rectal carriage of common ICU pathogens predicted specific infections. The gastrointestinal microbiome may have a role in risk stratification and early diagnosis of ICU infections.

The Role of Negative Methicillin-Resistant Staphylococcus aureus Nasal Surveillance Swabs in Predicting the Need for Empiric Vancomycin Therapy in Intensive Care Unit Patients.

OBJECTIVES The role of methicillin-resistant Staphylococcus aureus (MRSA) nasal surveillance swabs (nasal swabs) in guiding decisions about prescribing vancomycin is unclear. We aimed to determine the likelihood that patients with negative MRSA nasal swabs develop subsequent MRSA infections; to assess avoidable vancomycin days for patients with negative nasal swabs; and to identify risk factors for having a negative nasal swab and developing a MRSA infection during the intensive care unit (ICU) stay. METHODS This retrospective cohort study was conducted in 6 ICUs at a tertiary-care hospital from December 2013 through June 2015. The negative predictive value (NPV), defined as the ability of a negative nasal swab to predict no subsequent MRSA infection, was calculated. Days of vancomycin continued or restarted after 3 days from the collection time of the first negative nasal swab were determined. A matched case-control study identified risk factors for having a negative nasal swab and developing MRSA infection. RESULTS Of 11,441 patients with MRSA-negative nasal swabs, the rate of subsequent MRSA infection was 0.22%. A negative nasal swab had a NPV of 99.4% (95% confidence interval [CI], 99.1%-99.6%). Vancomycin was continued or started after nasal swab results were available in 1,431 patients, translating to 7,364 vancomycin days. No risk factors associated with MRSA infection were identified. CONCLUSIONS In our hospital with a low prevalence of MRSA transmission, a negative MRSA nasal swab was helpful in identifying patients with low risk of MRSA infection in whom empiric vancomycin therapy could be stopped and in whom the subsequent initiation of vancomycin therapy during an ICU admission could be avoided. Infect Control Hosp Epidemiol 2018;39:290-296.

Diagnostic value of superficial cultures for late-onset sepsis

Background: Late-onset sepsis (LOS) is associated with poor outcome and one of the prevalent causes of death in preterm population; hence, there is always a need for early prediction of sepsis. The performance of routine superficial swab culture is one of the strategies for the early prediction and may help in the selection of appropriate empirical antibiotics. Objective: The purpose of the study is to evaluate the diagnostic value of superficial swab cultures for LOS. Methods: We conducted a retrospective cohort study (November 2015-October 2016) in a tertiary neonatal intensive care. Inclusion criteria were preterm infants with gestationalage ?34 weeks with a diagnosis of sepsis (culture-positive and culture-negative clinical sepsis). In our unit, weekly surveillance swab cultures (skin swab, mouth swab, nasopharyngeal aspirate, and umbilical surface swab) are taken from all admitted neonates, and usually, no interventions are carried out based on these culture results. We excluded infants with surgical diagnosis/congenital anomalies and infants with early-onset sepsis. Results: After exclusion, there were 38 preterm infants fulfilling our inclusion criteria; among them, there were 108 LOS episodes. Blood culture was positive in 33 episodes, and Staphylococcus epidermidis (21%) was the most common organism cultured. In our study, superficial swab cultures had a very low diagnostic value, as sensitivity (42.9%), specificity (28.7%), predictive values, and likelihood ratio that all the estimations were low. Conclusions: Superficial swab cultures are associated with low diagnostic value for LOS. Superficial swab culture may be used surveillance of colonizing organism in the neonatal unit and provides antibiotic sensitivity pattern.

Sentinel surveillance data from Eritrean migrants in Italy: The theory of "Healthy Migrants".

Eritrean migrants accounted for the majority of people who drowned in the Mediterranean this year. Recently, data deficit about international migration has been reported. One hundred and thirty-three Eritrean migrants, upon their arrival in Italy, were accommodated at the asylum seekers center of Castelnuovo di Porto, together with 25 sanitary workers, and received microbiological surveillance at the Clinical Pathology and Microbiology Unit of the University Campus Bio-Medico of Rome. Gram-negative bacteria, mostly Klebsiella pneumoniae and Klebsiella oxytoca, were frequently recovered in surveillance swabs. Gram-positive bacteria, represented by Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus dysgalactiae and Staphylococcus aureus, were also isolated in surveillance swabs. In migrants, polymicrobial swabs were recovered at high frequency, and unusual microorganisms, rarely found in our country, were isolated. The polymicrobial colonization and the high prevalence of gram-negative bacteria represent the baseline characteristics of this migrant population from Eritrea. The presence of unusual microorganisms can be potentially pathogenic to asymptomatic carriers at risk of developing clinical disease if immunosuppressed or subjected to invasive procedures. In conclusion, active microbiological surveillance can represent an advantage for the host country in terms of data collection and by tracing unusual or resistant microorganisms by monitoring migrants' health status.

Cross transmission of multi resistant organisms, clinical specimens versus surveillance swabs

Cross transmission of multi resistant organisms, clinical specimens versus surveillance swabs

The Role of Negative Methicillin-Resistant Staphylococcus aureus Nasal Surveillance Swabs in Predicting the Need for Empiric Vancomycin Therapy

BackgroundThe role of MRSA nasal surveillance swabs in guiding decisions about need for subsequent vancomycin therapy is unclear. Our objectives were to (1) determine the likelihood that patients with negative MRSA nasal swabs went on to develop MRSA infections during the same hospitalizations to assess if vancomycin therapy could be avoided once the nasal swab result returns negative, (2) assess days of vancomycin that potentially could be avoided, and (3) identify risk factors for having a negative MRSA nasal swab and developing an MRSA infection during the hospital stay.MethodsThis retrospective cohort study was conducted at six intensive care units (ICUs) at a tertiary care hospital in Baltimore from December 2013 to June 2015. MRSA nasal swabs are obtained at the time of admission and weekly thereafter for all ICU patients. The negative predictive value (NPV), defined as the ability of a negative MRSA nasal screening test to correctly predict no subsequent MRSA infection during the hospital stay, was calculated, accounting for the 3-day turnaround time of MRSA nasal surveillance swabs. Days of vancomycin therapy started or continued after 3 days from the first negative MRSA nasal swab were determined by chart review. A matched case–control study was performed to identify risk factors for patients with negative MRSA surveillance cultures who subsequently developed MRSA infections.ResultsOf 11,441 MRSA-nasal swab negative patients, the proportion of subsequent incident MRSA infections was 0.2%. Negative MRSA surveillance swabs had an NPV of 99.4% (95% CI 99.1–99.6%). Among 4,091 MRSA-negative patients receiving vancomycin, vancomycin was started or continued after 3 days since the first MRSA-negative nasal swab in 1,434 patients (35%), translating to 7,377 potentially avoidable vancomycin days. The matched case–control analysis did not identify risk factors associated with subsequent MRSA infection.ConclusionAt our institution with robust infection control practices and low nosocomial MRSA transmission rates, patients with negative MRSA nasal swabs have a very low likelihood of subsequent MRSA infection during hospitalizations. MRSA nasal swabs can provide useful information when determining whether to initiate or stop empiric vancomycin.Disclosures All authors: No reported disclosures.

Risk Factors Associated with Isolation of Carbapenem-resistant Enterobacter sp. or Klebsiella sp. in Stool or Rectal Swab Surveillance Cultures Using a Matched Case–Control Sample of Patients Hospitalized Between 2013 and 2015 Across a Large Integrated Healthcare System

Risk Factors Associated with Isolation of Carbapenem-resistant Enterobacter sp. or Klebsiella sp. in Stool or Rectal Swab Surveillance Cultures Using a Matched Case–Control Sample of Patients Hospitalized Between 2013 and 2015 Across a Large Integrated Healthcare System

Control of infectious mortality due to carbapenemase-producing Klebsiella pneumoniae in hematopoietic stem cell transplantation.

Carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) infections are an emerging cause of death after hematopoietic stem cell transplantation (HSCT). In allogeneic transplants, mortality rate may rise up to 60%. We retrospectively evaluated 540 patients receiving a transplant from an auto- or an allogeneic source between January 2011 and October 2015. After an Institutional increase in the prevalence of KPC-Kp bloodstream infections (BSI) in June 2012, from July 2012, 366 consecutive patients received the following preventive measures: (i) weekly rectal swabs for surveillance; (ii) contact precautions in carriers (iii) early-targeted therapy in neutropenic febrile carriers. Molecular typing identified KPC-Kp clone ST512 as the main clone responsible for colonization, BSI and outbreaks. After the introduction of these preventive measures, the cumulative incidence of KPC-Kp BSI (P=0.01) and septic shocks (P=0.01) at 1 year after HSCT was significantly reduced. KPC-Kp infection-mortality dropped from 62.5% (pre-intervention) to 16.6% (post-intervention). Day 100 transplant-related mortality and KPC-Kp infection-related mortality after allogeneic HSCT were reduced from 22% to 10% (P=0.001) and from 4% to 1% (P=0.04), respectively. None of the pre-HSCT carriers was excluded from transplant. These results suggest that active surveillance, contact precautions and early-targeted therapies, may efficiently control KPC-Kp spread and related mortality even after allogeneic HSCT.

The evaluation of MRSA surveillance cultures by the number and combinations of anatomical sites.

IntroductionThe identification of patients infected and/or colonised by methicillin resistant Staphylococcus aureus (MRSA) is necessary for the timely introduction of measures for infection control. We compared the diagnostic efficacy of combinations of MRSA surveillance swabs routinely taken by health institutions in the country.MethodsAll surveillance samples, which were sent for a microbiological analysis to detect MRSA with the culture method in 2014, in the three departments for medical microbiology of the National Laboratory for Health, Environment and Food, were included in this study.ResultsAmong 65,251 surveillance cultures from 13,274 persons, 1,233 (2.1%) were positive (490 positive persons). Prevailing positive surveillance cultures were throat swabs (31.3%), followed by nose swab (31.2%), skin swab (18.9%), perineum (16.4%) and wound swabs (1.4%). The contribution of other samples, such as aspirate, urine and excreta, was under 1%. We found no statistically significant differences in the frequency of detection of a positive patient, if the combination of samples NTS (nose, throat, skin) or NTP (nose, throat, perineum) was analysed. However, statistically significant differences were confirmed when any of the anatomic sites would be omitted from the sets of NTP and NTS (chi square; p<0.01). Adding additional samples resulted in only 24 additional positive patients (4.9%).ConclusionsThe results indicate that increasing the number of surveillance cultures above three does not add much to the sensitivity of MRSA surveillance, the exception could be wound. The swabs from the perineum and from the skin are exchangeable.

Lack of doxycycline antimalarial prophylaxis impact on Staphylococcus aureus tetracycline resistance

There is concern that susceptibility of Staphylococcus aureus to tetracyclines may decrease due to use of antimalarial prophylaxis (doxycycline). We examined characteristics related to tetracycline resistance, including doxycycline exposure, in S. aureus isolates collected via admission surveillance swabs and inpatient clinical cultures from United States military personnel injured during deployment (June 2009–January 2012). Tetracycline class resistance was determined using antimicrobial susceptibility testing. The first S. aureus isolate from 168 patients were analyzed, of which 38 (23%) isolates were resistant to tetracyclines (class). Tetracycline-resistant isolates had a higher proportion of resistance to clindamycin (P=0.019) compared to susceptible isolates. There was no significant difference in tetracycline resistance between isolates collected from patients with and without antimalarial prophylaxis; however, significantly more isolates had tet(M) resistance genes in the doxycycline exposure group (P=0.031). Despite 55% of the patients receiving doxycycline as antimalarial prophylaxis, there was no association with resistance to tetracyclines.

Complete Genome Sequence of a Klebsiella pneumoniae Strain Carrying blaNDM-1 on a Multidrug Resistance Plasmid.

Here, we report the genome sequence of a blaNDM-1-positive Klebsiella pneumoniae AATZP isolate cultured from a perirectal surveillance swab collected upon admission of a patient to the NIH Clinical Center in 2014. Genome sequencing of this isolate revealed three plasmids, including one carrying the blaNDM-1 gene encoding resistance to carbapenems.