Outbreak Of Bacteremia Research Articles

Enterococcal Bacteremia outbreaks during SARS-COV-2 in Intensive Care Unit (ICU): The role of Strain Identification

Background: An unprecedented burden of morbidity and mortality has been reported in patients admitted to healthcare facilities with SARS-COV-2 infection globally since March 2020. A higher incidence of ICU-acquired bloodstream infection has been described with the cumulative risk increased with the length of ICU stay, use of steroids, anti-inflammatory agents, and indwelling catheters. Additionally, SARS-COV-2 infection may increase the risk of bacteremia from gastrointestinal flora such as Enterococcus species by disrupting the gastrointestinal barrier and microbiome. Methods: We aimed to investigate the outbreaks of Enterococcus bacteremia in patients with SARS-COV-2 infection and included patients aged>18 years admitted to the ICU at the Oklahoma City Veterans Affairs Medical Center who were infected with SARS-COV-2 and were identified as having positive blood cultures for Enterococcus faecalis, Enterococcus faecium including vancomycin-resistant species and other bacterial or candida species between March 1, 2020, to March 9, 2022. We collected the following data: duration of hospitalization including ICU stay, unit and room location during the hospital stay, blood culture collection date and results, duration, and site of central line placement, duration of ventilation, administration of antimicrobials and COVID-19 directed therapeutics using computerized patient record system (CPRS). We sent 10 E. faecalis and 12 E. Faecium isolates for genetic analysis. DNA was sequestered from each isolate and multi-locus sequence typing (MLST) was performed by amplifying 7 regions of the E. faecalis genome and 7 regions of the E. faecium genome by polymerase chain reaction (PCR). Resulting amplicons were sequenced and allele type for each gene region and overall sequence type was determined using MLST database (http://pubmlst.org). Results: There were 22 episodes of enterococcal bacteremia in a 3-month duration in the ICU in 20 patients of which 17 were associated with another episode with the same strain (Figure-1-2). Central line placement was noted in 18/22 episodes. Genetic analysis by multi-locus sequence typing of enterococcal bacterial strains was performed by the Public Health Reference Laboratory, Palo Alto. Similar strains were localized to patients in the same geographical region in the ICU (Figure 3). The isolates from 2 other patients who presented with the same strain of Enterococcus but were never hospitalized at the same time during the COVID-19 pandemic were localized to another hospital where both had received care at different times. Conclusion: Higher rates of enterococcal bacteremia were reported during the SARS-COV-2 pandemic. Geographical proximity with strained infection control measures accounted for ICU outbreaks seen in our tertiary care setup.

Clinical impact and public health challenges of a PVL-MRSA bacteraemia outbreak amongst people who inject drugs in South Yorkshire, UK.

Panton-Valentine leukocidin (PVL) Staphylococcus aureus (SA) is an emergent public health concern. PVL toxin has been mostly associated with methicillin-sensitive S. aureus (MSSA)-related skin and soft tissue infections occurring in high-risk groups such as people who inject drugs (PWID). The emergence of PVL methicillin-resistant S. aureus (MRSA) infection is causing severe and life-threatening disease in PWID. We present an outbreak of eight PVL-MRSA bacteraemia cases at a UK teaching hospital between 2018 and 2022. An additional four patients developed bacteraemia with PVL-negative MRSA of the same multilocus sequence type (MLST). All patients were PWID and aged 33-51 years old. Four patients developed MRSA bacterial endocarditis. Three patients died. These cases represent the initial cases detected at Doncaster and Bassetlaw Teaching Hospitals of what is an ongoing and developing outbreak. An outbreak investigation has been undertaken in association with the UK Health Security Agency. Epidemiological factors have been explored, including via direct contact at a local sheltered accommodation and the possibility of a contaminated drug supply. Whole-genome sequencing confirmed that all isolates were closely related and of the same MLST (sequence type 5). A community substance misuse group disseminated health education on the prevention of PVL-MRSA. Preventing infection in PWID presents a major challenge due to the impact of addiction on engagement with services and the significant barriers faced by our patients in observing infection prevention measures. PVL-MRSA is of major public health concern and outbreak investigation and mapping out local epidemiological patterns plays a vital role in preventing further spread throughout the community. Additionally, this work enables targeted and early treatment in patients in high-risk categories for disease. These cases of PVL-MRSA infection in PWID highlights the transmissibility, pathogenic potential and severe clinical disease spectrum within this population. Further work is required to tackle transmission and infection from this pathogenic strain.

An outbreak of Providencia rettgeri bacteremia at a Ptyas mucosus farm in Hainan, China.

To describe the histopathology and etiology of an outbreak of respiratory disease at a Ptyas mucosus farm in Hainan, China. The etiology was confirmed by gross examination and microscopic analysis. The bacterial isolates from blood and internal organs were identified by biochemical analysis and 16S rRNA gene sequencing. The virulence and antibiotic resistance characteristics of the isolates were further demonstrated by polymerase chain reaction (PCR), disk diffusion testing, and LD50 analysis in Kunming mice. Histopathological analysis of the diseased P. mucosus revealed systemic lesions, including severe airway obstruction with large numbers of inflammatory cells and cellulose exudates in the lungs; severe multifocal hepatocyte vacuolar degeneration and necrosis in the liver with excessive inflammatory exudates and chronic granuloma; splenic hemorrhage and partial loss of splenic structure; and renal vascular and interstitial congestion. Providencia rettgeri was isolated from the blood and multiple internal organs (liver, spleen, kidneys, and lungs). All examined isolates (H1, H4, and H13) were multidrug-resistant but sensitive to four antibiotics-cefepime, imipenem, chloramphenicol, and ciprofloxacin. Both H1 and H4 carried five resistance genes [bla OXA, tet(A), tet(B), tet(E), and aac (3)-IIa], whereas H13 only carried the tet(A) gene. The dominant virulence pattern of the three isolates was hlyA + ZapA + luxS + rsbA. The virulence of H1 strain was tested, and its 50% lethal dose (LD50) in mice was 2.29 × 108 CFU ml-1. To our knowledge, this is the first study to describe an outbreak of bacteremia caused by P. rettgeri in farmed rat snakes. The results highlight that P. rettgeri is an emerging bacterial pathogen in farmed reptiles.

An Outbreak of Ralstonia mannitolilytica Septicaemia at a Tertiary Care Hospital: An Observational Cross-sectional Study

Introduction: Ralstonia spp. is an emerging non fermenting Gram negative bacillus implicated in cases of bloodstream infections in immunocompromised individuals. It is commonly found as an environmental contaminant in hospital settings. Several sporadic outbreaks have been reported from different parts of the world due to Ralstonia spp. This study reports a similar outbreak at a tertiary care hospital in Northern India. Aim: To determine the source of Ralstonia septicaemia in affected patients at a tertiary care centre. Materials and Methods: The present observational crosssectional study was conducted at the Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, Uttar Pradesh, India from February 2020 until the end of March 2020 (two months). A total of 2,650 blood cultures were received during the study period; of these, 53 (2%) patients were found to have Ralstonia mannitolilytica infection over a two month period. All patients from various wards whose blood cultures showed growth of Ralstonia species were included in this study. The organism was identified using both biochemical tests and Matrix-Assisted Laser Desorption Ionisation-Time of Flight Mass Spectrometry (MALDI-TOF MS). Antibiotic sensitivity testing was conducted using the Kirby-Bauer disk diffusion assay. Environmental surveillance was conducted to detect the source of origin. Patients’ age, sex, duration of hospital stay, co-morbidities, and other clinical parameters were recorded. Statistical analysis was performed using Microsoft Excel. Results: There were 52 cases of septicaemia due to Ralstonia mannitolilytica, and one Ralstonia isolate was obtained from intraoperative pus. Most of the Ralstonia isolates obtained were Multidrug-Resistant (MDR), showing resistance to imipenem, meropenem, amikacin, aztreonam, and sensitivity to first-line drugs such as ceftazidime, piperacillin-tazobactam, cefoperazone-sulbactam, levofloxacin, and trimethoprimsulfamethoxazole, resulting in successful treatment. Out of 53 cases, one patient succumbed to death due to surgical complications. Environmental sampling did not yield any organisms resembling Ralstonia spp. Conclusion: The environmental source of the Ralstonia bacteraemia outbreak could not be identified in this study. All patients except one were successfully treated with antibiotics. Clinicians and microbiologists should remain vigilant in case any such case arises to prevent further outbreaks.

1679. Successful Control of MSSA Bacteremia Outbreak in Neonatal Intensive Care Unit

Abstract Background Staphylococcus aureus outbreaks in the neonatal intensive care units (NICU) have been reported with the great majority due to methicillin-resistant Staphylococcus aureus. We describe successful control of an outbreak caused by methicillin-susceptible S. aureus (MSSA) in the NICU. Methods We report a MSSA bacteremia outbreak which occurred in the NICU at a tertiary level hospital from November 29, 2020 to January 6, 2021. Molecular typing of MSSA isolates were performed including multi-locus sequence typing (ST) and spa typing. Results A total of 5 MSSA bacteremia cases occurred in 39 days. Outbreak investigation was initiated after the 5th case. Infection control measures, including isolation of cases, contact precaution and universal 0.5% chlorhexidine bathing of all NICU patients, were implemented. Surveillance cultures of patients (n=36) and health care workers (HCW) (n=60) were performed. Excluding bacteremia patients, 13% (4/31) of neonates and 32% (19/60) of HCW were identified as MSSA nasal carriers and targeted decolonization with intranasal mupirocin was performed. After implementation of control measures and decolonization, there were no new cases. Molecular analysis identified two strains [ST15 spa type t593 (n=3) and ST101 spa type t4171 (n=2)] as the cause of this bacteremia outbreak. Among MSSA nasal carriers, all 4 neonates colonized the ST15 spa t593 strain. ST15 spa t593 strain was also colonized in one HCW, however antibiotic susceptibility pattern differed. The rest of HCWs colonized many different types of MSSA. All MSSA isolates were negative for Panton-Valentine Leucocidin toxin gene. Conclusion Molecular analysis identified two different MSSA strains in this outbreak. MSSA colonization was prevalent among HCWs, however molecular analysis showed variance in distribution. Although outbreak strains were not found in HCWs, one strain was colonized among other neonates, suggesting horizontal transmission and potential of further cases. The outbreak was successfully controlled with reinforcement of precautions, universal chlorhexidine bathing and surveillance cultures with targeted decolonization. Early recognition and prompt implementation of control measures are important for outbreak control in NICU. Disclosures All Authors: No reported disclosures

Outbreak of Serratia marcescens in the Neonatal Intensive Care Unit of a Tertiary Care Hospital in Mexico.

We describe an outbreak of Serratia marcescens (S. marcescens) infection in the neonatal intensive care unit at Women's Hospital in Sinaloa, Mexico. In April 2021, an outbreak of S. marcescens infection was identified. A case was identified as any patient who tested positive for S. marcescens and showed signs of an infectious process. S. marcescens was isolated from the blood cultures of 15 neonates with clinical signs of neonatal sepsis. Statistical analysis showed that all neonates had an invasive medical device. The problem was controlled after hospital hygiene and sanitation measures were strengthened. The study provides evidence of an outbreak of nosocomial bacteremia due to the cross-transmission of S. marcescens. The findings highlight the need for hospitals to implement strict hygiene measures, especially regarding hand washing, to prevent future outbreaks.

#4562 OUTBREAK OF RALSTONIA SPP AND BURKHOLDERIA SPP CATHETER-RELATED BLOODSTREAM INFECTION IN A HAEMODIALYSIS UNIT

Abstract Background and Aims Ralstonia (RB) and Burkholderia (BB) species are environmental Gram-negative bacilli responsible for several nosocomial infections in immunocompromised or frail patients. RB and BB may contaminate medical devices because of their ability to survive in a biofilm and with low nutrient requests. Reports of infection outbreaks due to RB and BB are very few and only in sporadic cases, the source of contamination was identified. We describe here: i) how we managed an outbreak of bacteremia caused by RB and BB occurred in our dialysis unit, ii) what we have done to identify the source of infection and iii) the countermeasures we adopted to reduce the risk of new events. Method From 7 to 16 April 2021, 6 out of 39 (15.4%) hemodialyzed (HD) patients with a long-term indwelling central venous catheter (CVC) developed symptoms related to infection. Blood cultures revealed the presence of RB and BB. Thus, a prompt check of the blood cultures of all HD patients with CVC was performed. Blood samples were incubated in an automated microbial detection system (VIRTUO BIOMERIEUX) and subsequently, blood positive samples were inoculated in Chocolate and Columbia blood Agar plates. In addition, a microbiological analysis of disinfectants, drugs used in dialysis unit and samples collected from the reverse osmosis water unit (ROW) and from the ROW delivery line were performed. None of the samples obtained from the ROW and from the ROW delivery line resulted positive. Thus, a microbiological analysis of the biofilm attached on the loading pipes (LP) and on the loading plastic tubes (LPT) that connect the hemodialyzer consoles (HC) to the ROW delivery line were performed. Briefly, LTP were subjected to ultrasound sonication at 30-40 KHz (BactoSonic-Bandelin), to disrupt the bacterial biofilm. The material obtained from sonication was cultured. Bacteria was identified by an automated mass spectrometry (MALDI-TOF VITEK®MS, Biomerieux). Results Bacteremia due to RB and BB was confirmed in 7 out of 39 (17.9%) of the hemodialyzed patients with a long-term indwelling CVC. 1 out of 7 was asymptomatic. Baseline characteristics of the 6 symptomatic patients were: mean age 68±16 years; mean C-reactive protein 4.48±1.3 mg/dl; mean procalcitonin 13.27±11.07 ng/ml; mean body temperature 37.9±1.4°C. The antibiotic therapy was decided according to antibiogram and included meropenem and ciprofloxacin. CVC were removed in all infected patients between 6 to 11 days from the diagnosis. Concomitantly, a new one was placed. None of the HD patients with arterio-venous fistulae developed bacteremia. RB and BB were isolated in the biofilm of 11 out of 37 LPT. Thus, we modified the ROW delivery line in order to set up a scheduled chemical and physical disinfections of the ROW delivery line with the hemodialysis consoles connected avoiding the risk of new contamination of the LPT and loading pipes. Briefly, on alternate months the whole system that include ROW delivery line (PE-Xa Medical Device, Fresenius Medical Care), loading pipes, LPT and hemodialysis consoles are disinfected by hot water (90°C) produced by a water heater (AquaB plus HF, Fresenius Medical Care) and by chemical disinfectant, 5% peracetic acid according to the protocols made by the console fabricant. In addition, we added to the reverse osmosis system a filtration module of 0.01 μm (AquaUF, Fresenius Medical Care) prior to the ROW delivery line, Figure 1. Awaiting for the modification of the ROW delivery line, the patients with CVC were dialyzed using a portable water treatment unit. After more than 14 months from the modification of the whole system for production and delivery of ROW none of the hemodialyzed patients developed infection by RB and BB. Conclusion Our experience suggests that infection outbreak by unusual bacteria such as RB and BB could be successful treated using antibiotic therapy. Nevertheless, in dialysis unit the source of infection should be investigated in order to adopt the countermeasures necessary to reduce the risk of new infections.

Polyclonal Burkholderia cepacia complex outbreak caused by contaminated chlorhexidine gluconate solution

Background:Burkholderia cepacia complex is an opportunistic environmental pathogen that has been linked to nosocomial outbreaks. We describe an outbreak of bacteremia caused by Burkholderia cenocepacia from a contaminated chlorhexidine gluconate solution. Methods: The hospital infection control team carried out an outbreak investigation on February 21, 2021, when 3 adult hemodialysis patients developed B. cenocepacia bacteremia. Patient demographics and clinical profile were reviewed retrospectively. Potential sources of infection were identified, and environmental screening was performed in several units. Processes of catheter care in the hemodialysis unit were reviewed. Water samples from the hemodialysis unit, and samples of solutions used in patient care were sent for culture. Isolates from patients and from environmental samples were sent for 16S rRNA gene sequencing to determine genetic relatedness. Results: In total, 16 patients, 8 of whom were male, developed B. cenocepacia bacteremia during the investigated period. The median age was 68 years (range, 19–83), and 15 of 16 had at least 1 comorbidity. All patients used a central venous catheter (CVC) for hemodialysis, and 11 (70%) of these 16 were temporary. Chlorhexidine gluconate solution was routinely used as part of CVC care and 1 bottle was shared among 4 hemodialysis stations. On suspicion of contamination, all identified chlorhexidine bottles were recalled on February 26, 2021, and random samples from 15 opened and 19 unopened bottles were sent for culture from the following units: hemodialysis (n = 2), ICU (n = 14), wards (n = 6), and 4 each from transplant surgery, and delivery suites. O0f 34 sampled bottles, 17 grew B. cenocepacia: 8 opened and 9 unopened bottles. The Bayesian inference tree (Fig. 1) supports the hypothesis that patient samples and the samples from the chlorhexidine solutions were most probably related to each other based on the 16S rRNA sequences. However, the individual identities of the specific sample sequences could not be determined using the analyzed region of the gene, possibly due to low quality of the sequences received. No new cases of B. cenocepacia were identified after recall of the chlorhexidine solution, and the outbreak was deemed resolved on March 24, 2021. Conclusions: Medical solutions routinely used in patient care can cause outbreaks and should be suspected as a potential source of infection by infection control teams.Disclosures: None

Pangenome profiling of novel drug target against vancomycin-resistant Enterococcus faecium

Enterococcus faecium is a frequent causative agent of nosocomial infection mainly acquired from outgoing hospital patients (Hospital Acquired Infection—HAIs). They are largely involved in the outbreaks of bacteremia, UTI, and endocarditis with a high transmissibility rate. The recent emergence of VRE strain (i.e. vancomycin resistant enterococcus) turned it into high priority pathogen for which new drug research is of dire need. Therefore, in current study, pangenome and resistome analyses were performed for available antibiotic-resistant genomes (n = 216) of E. faecium. It resulted in the prediction of around 5,059 genes as an accessory gene, 1,076 genes as core and 1,558 genes made up a unique genome fraction. Core genes common to all strains were further used for the identification of potent drug targets by applying subtractive genomics approach. Moreover, the COG functional analysis showed that these genomes are highly enriched in metabolic pathways such as in translational, ribosomal, proteins, carbohydrates and nucleotide transport metabolism. Through subtractive genomics it was observed that 431 proteins were non-homologous to the human proteome, 166 identified as essential for pathogen survival while 26 as potential and unique therapeutic targets. Finally, 3-dehydroquinate dehydrogenase was proposed as a potent drug target for further therapeutic candidate identification. Moreover, the molecular docking and dynamic simulation technique were applied to performed a virtual screening of natural product libraries (i.e., TCM and Ayurvedic compounds) along with 3-amino-4,5-dihydroxy-cyclohex-1-enecarboxylate (DHS) as a standard compound to validate the study. Consequently, Argeloside I, Apigenin-7-O-gentiobioside (from Ayurvedic library), ZINC85571062, and ZINC85570908 (TCM library) compounds were identified as potential inhibitors of 3-dehydroquinate dehydrogenase. The study proposed new compounds as novel therapeutics, however, further experimental validation is needed as a follow-up. Communicated by Ramaswamy H. Sarma

Outbreak of healthcare-associated bacteremia caused by Burkholderia gladioli due to contaminated multidose vials with saline solutions in three Croatian hospitals

Burkholderia gladioli has been associated with infections in patients with cystic fibrosis, chronic granulomatous disease, and other immunocompromising conditions. The aim of this study was to better depict the outbreak of healthcare-associated bacteremia caused by B. gladioli due to exposure to contaminated multidose vials with saline solutions. An environmental and epidemiologic investigation was conducted by the Infection Prevention and Control Team (IPCT) to identify the source of the outbreak in three Croatian hospitals. During a 3-month period, 13 B. gladioli bacteremia episodes were identified in 10 patients in three Croatian hospitals. At the time of the outbreak, all three hospitals used saline products from the same manufacturer. Two 100-ml multidose vials with saline solutions and needleless dispensing pins were positive for B. gladioli. All 13 bacteremia isolates and two isolates from the saline showed the same antimicrobial susceptibility patterns and pulsed-field gel electrophoresis profile, demonstrating clonal relatedness. When an environmental pathogen causes an outbreak, contamination of intravenous products must be considered. Close communication between the local IPCT and the National Hospital Infection Control Advisory Committee is essential to conduct a prompt and thorough investigation and find the source of the outbreak.

The Bad Bug is Back: Acinetobacter Baumannii Bacteremia Outbreak during the COVID-19 Pandemic in an Intensive Care Unit.

Epidemiology of nosocomial infections may show variability because of under-estimation of infection control measures (ICMs) in coronavirus disease 19 (COVID-19) outbreak. To investigate the Acinetobacter bacteremia outbreak developed in an intensive care unit (ICU) between March 20 to May 15, 2020, examine the risk factors, and re-evaluate ICM retrospectively. A retrospective cohort analysis was conducted to determine the risk factors, pulsed field gel electrophoresis (PFGE) was performed for analysis of the outbreak, ICM practices were observed by a team, and infection control interventions were undertaken. Acinetobacter bacteremia developed in 17 patients (21.5%) within 79 COVID-19 patients included in the study. The mean age of the bacteremic patients was 67.3 (SD = 14.82) years, and 82.4% of them were male; of these, 15 died, leading to 88.2% mortality. The bacteremia rate was higher compared with a 14-month period preceding the COVID-19 pandemic (17/79 versus 12/580 patients, respectively). PFGE revealed that the outbreak was polyclonal. On multi-variate analysis, the bacteremia development rate was 13.7 and 5.06 times higher with central venous catheter (CVC) use and in patients with chronic obstructive pulmonary disease (COPD), respectively. The mortality rate was higher in bacteremic patients (p = 0.0016). It was observed that ICMs were not followed completely, especially change of gloves and hand hygiene. Contamination of A. baumannii was observed in 38% of the gloves. COPD and CVC use were determined as risk factors for Acinetobacter bacteremia development, and failures in ICM may have led to cross-contamination of endemic A. baumannii. The outbreak could be controlled within 3 weeks of interventions.

An outbreak of Ralstonia pickettii bloodstream infection and clinical outcomes.

Ralstonia pickettii infections are rare and may be mistaken for other bacteria. This study aims to report a hospital outbreak of R. pickettii at a tertiary hospital, which was initially misidentified as Ralstonia insidiosa, along with its clinical consequences. A bacteraemia outbreak occurred between August 14 and October 4, 2019, infecting 22 patients admitted to diverse intensive care units. All isolates were identified with the use of the automated VITEK 2 Compact system and were then subjected to a microbial identification system, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Bacterial identification and genomic DNA typing was made using pulsed-field gel electrophoresis. Investigation covered all potential sources of the outbreak. An index patient and five additional patients developed fever while receiving care. Blood cultures of these patients yielded R. insidiosa by the VITEK 2 Compact system. Culture isolates were then submitted to a reference centre for confirmation by the MALDI-TOF MS system, where the bacterium turned out to be R. pickettii. No pathogen was isolated in the commercial products except for three samples of unopened sterile distilled water. Despite its discontinuation, 16 new cases were identified, in which blood cultures grew R. pickettii by the MALDI-TOF MS system. Attempts to uncover the source of the outbreak failed. Clinical manifestation was confined to fever in all the patients. During this outbreak, R. pickettii infections ran a relatively mild course without clinical deterioration or mortality, possibly due to low virulence.

Polyclonal outbreak of bacteremia caused by Burkholderia cepacia in the intensive care unit

Polyclonal outbreak of bacteremia caused by Burkholderia cepacia in the intensive care unit

Achromobacter spp. bacteremia outbreak related to contaminated furosemide ampoules

Nosocomial outbreaks related to medication contamination are reported world-wide. A sudden increase in cases of Achromobacter spp. bacteremia led to an outbreak investigation in our setting. Line listing and environmental sampling led to identification of contaminated furosemide ampoules as the source. Molecular identification helped in species identification and in this outbreak more than one species was identified. Prompt withdrawal of the contaminated batch of ampoules curtailed the outbreak.

Diagnostic methods and identification challenges experienced in a Burkholderia contaminans outbreak occurred in a tertiary care centre

BackgroundRecently, a novel species contaminans belonging to the family Burkholderia cepacia complex (Bcc) is rising as a hospital pathogen. Detection of Burkholderia contaminans, a member of Bcc can be done only by MALDI TOF and sequencing techniques. We report the diagnostic challenges faced in an outbreak of bacteremia due to B. contaminans grown in diltiazem vials. MethodThe department of microbiology notified the infection control team about a cluster of eleven patients with B. contaminans isolated from blood culture. An outbreak investigation was initiated by performing environmental surveillance and sterility testing of solutions given for the patients. Routine phenotypical methods for identification of species followed by MALDI-TOF and sequencing was performed to identify the pathogen. ResultsAll the patients detected with B. contaminans were having cardiac disease and received diltiazem. Sterility testing of diltiazem vials given for the patient and an unopened vial of same batch has grown B. contaminans. Clonal typing has confirmed the sequence similarities between patient and solution isolates. ConclusionDue to diagnostic challenge in identifying the species of Bcc, MALDI TOF and clonal typing remains the key diagnostic tools available to detect Bcc species at an earliest especially in an outbreak.

The impact of pneumococcal conjugate vaccine-13 on the incidence of pediatric community-acquired bacteremia.

The purpose of this study was to estimate the impact of pneumococcal conjugate vaccine-13 (PCV-13) introduction into the national immunization program in Israel on pneumococcal and non-pneumococcal pediatric community-acquired bacteremia (CAB). This is a retrospective cohort study, including children ≤ 18 years old with CAB, who were hospitalized in Rambam Health Care Campus, a tertiary medical center serving northern Israel, between the years 2004 and 2016. The proportional admission rate of pneumococcal bacteremia among all CAB events and the incidence of CAB and pneumococcal bacteremia per 1000 hospital admissions were compared between the pre- and post-pneumococcal vaccine eras. A total of 275 CAB events were identified. Common isolates were Streptococcus pneumoniae (SPn) (26.9%), Staphylococcus aureus (12.4%), Brucella spp. (11.6%), E. coli (10.9%), and Streptococcus pyogenes (5.8%). The pneumococcal bacteremia rate per 1000 hospital admissions decreased significantly from 1.59 to 0.6 (p < 0.001). The proportional pneumococcal bacteremia rate decreased from 55 (34.4%) to 19 (16.5%) (p 0.001). Penicillin resistance among pneumococcal isolates decreased dramatically from 50.9 to 5.3% (p < 0.001). The rate of bacteremia caused by other pathogens has not been changed significantly at the post-vaccination era (p 0.053). However, an increase in the incidence of S. pyogenes bacteremia from 1.9 to 11.3% (p < 0.001) was noticed. In addition, an outbreak of Brucella bacteremia occurred during the years 2015-2016. This study demonstrates the double positive effect of PVC-13 introduction: a sharp decrease in the proportional rate of pneumococcal bacteremia and in the resistance of SPn to penicillin. Also, there was a moderate decline in the incidence of CAB in exception to bacteremia caused by S. pyogenes. This trend was reversed due to a Brucella outbreak.

Outbreak of Bacillus bacteremia from contaminated hospital linens

Outbreak of Bacillus bacteremia from contaminated hospital linens

Pseudo outbreak of Bacillus bacteraemia associated with contaminated linen in a tertiary hospital

Pseudo outbreak of Bacillus bacteraemia associated with contaminated linen in a tertiary hospital

Emergence of Enteroaggregative Escherichia coli within the ST131 Lineage as a Cause of Extraintestinal Infections.

Escherichia coli sequence type 131 (ST131) is a major cause of urinary and bloodstream infections. Its association with extended-spectrum β-lactamases (ESBLs) significantly complicates treatment. Its best-described component is the rapidly expanding H30Rx clade, containing allele 30 of the type 1 fimbrial adhesin gene fimH This lineage appears to have emerged in the United States and spread around the world in part due to the acquisition of the ESBL-encoding blaCTX-M-15 gene and resistance to fluoroquinolones. However, non-H30 ST131 sublineages with other acquired CTX-M-type resistance genes are also emerging. Based on whole-genome analyses, we describe here the presence of an (fimH) H27 E. coli ST131 sublineage that has recently caused an outbreak of community-acquired bacteremia and recurrent urinary tract infections (UTIs) in Denmark. This sublineage has acquired both a virulence plasmid (pAA) that defines the enteroaggregative E. coli (EAEC) diarrheagenic pathotype and multiple genes associated with extraintestinal E. coli (ExPEC); combined, these traits have made this particular ST131 sublineage successful at colonizing its human host and causing recurrent UTI. Moreover, using a historic World Health Organization (WHO) E. coli collection and publicly available genome sequences, we identified a global H27 EAEC ST131 sublineage that dates back as far as 1998. Most H27 EAEC ST131 isolates harbor pAA or pAA-like plasmids, and our analysis strongly implies a single ancestral acquisition among these isolates. These findings illustrate both the profound plasticity of this important pathogenic E. coli ST131 H27 sublineage and genetic acquisitions of EAEC-specific virulence traits that likely confer an enhanced ability to cause intestinal colonization.IMPORTANCEE. coli ST131 is an important extraintestinal pathogenic lineage. A signature characteristic of ST131 is its ability to asymptomatically colonize the gastrointestinal tract and then opportunistically cause extraintestinal infections, such as cystitis, pyelonephritis, and urosepsis. In this study, we identified an ST131 H27 sublineage that has acquired the enteroaggregative diarrheagenic phenotype, spread across multiple continents, and caused multiple outbreaks of community-acquired ESBL-associated bloodstream infections in Denmark. The strain's ability to both cause diarrhea and innocuously colonize the human gastrointestinal tract may facilitate its dissemination and establishment in the community.

448. Impact of Doxycycline Prophylaxis on Skin and Soft-Tissue Infection Incidence in Naval Special Warfare Trainees

BackgroundSkin and soft-tissue infections (SSTIs) are a common complication of military training. Naval Special Warfare (NSW) training requires prolonged periods of extreme physical exertion and unique environmental exposures, including extended immersion in ocean water. A centerpiece of SEAL training is referred to as “Hell Week” (HW), a colloquial term to reflect the intense physical obstacles and exposure to extreme environmental conditions endured by candidates. Due to such environmental exposures, NSW trainees are at increased risk for SSTI due to uncommon organisms. A prior outbreak of Shewanella SSTI and bacteremia among NSW trainees led to the initiation of prophylactic doxycycline 100 mg daily during and for 7 days after HW to attempt to reduce this risk. The efficacy of this intervention is undetermined.MethodsDoxycycline prophylaxis was initiated in August 2015. We conducted a retrospective analysis of SSTI incidence presenting for medical attention among NSW trainees from April 2013 to November 2018, using case records collected prospectively at the Naval Special Warfare Center. The incidence of SSTI was calculated based on the size of a given class and the number of affected trainees. SSTI cases were then divided and analyzed as occurring during vs. after HW.ResultsThe pre-intervention cohort consisted of 1626 NSW trainees. A total of 76 trainees developed SSTI, with 20 cases during HW and 56 cases in the post-HW period. In the post-intervention cohort, 2022 trainees experienced a total of 81 cases of SSTI during HW and 83 in the post-HW period. 45% of all SSTI cases occurred in the months of June, July, and August. The incidence of cellulitis between the pre- and post-intervention cohorts during HW was 2% and 4%, respectively, and 5% and 6.4% in the post-HW period. There were no hospitalizations for invasive gram-negative infections following the initiation of doxycycline prophylaxis.ConclusionDoxycycline prophylaxis does not appear to reduce the incidence of SSTI but may reduce the incidence of certain severe infections. The choice of antibiotic prophylaxis and dosing may require further investigation. Seasonality of SSTI among NSW trainees is an unexpected finding and may provide valuable information for the prevention of future illness. Disclosures All authors: No reported disclosures.