Characterization of initial CLABSI culture results to support antimicrobial de-escalation in pediatric GI inpatients.

OBJECTIVES: Central Line-associated Bloodstream Infections (CLABSIs) pose a serious mortality and morbidity risk. An institutional protocol was developed for the evaluation and empirical antibiotic treatment of possible CLABSIs. The potential impact of de-escalating antimicrobial therapy based on initial Gram stain and molecular identification was assessed. METHODS: All positive blood cultures from patients admitted to the gastroenterology service at a large pediatric medical center were collected from 1/1/14 to 12/31/20. Cultures that were negative, repeated, or causative organisms that were unable to be identified with susceptibility data were excluded. Timepoints and organism(s) from each culture were recorded. Polymicrobial cultures were classified as containing only gram-positive organisms (polymicrobial GP), only gram-negative organisms (polymicrobial GN), or mixed spectrum. RESULTS: During the 6-year period, 361 positive blood cultures were included in the study. Single isolates were identified in 79.5% (287/361) of cultures. Polymicrobial cultures from confirmed central line source accounted for 15.0% (54/361), with 6.4% (23/361) Polymicrobial GP, 4.4% (16/361) Polymicrobial GN, and 4.2% (15/361) being mixed-spectrum cultures. Both organism types were detected on initial gram-stain in 40% (6/15) of the mixed-spectrum cultures, another 26.7% (4/15) had the opposite-spectrum organism identified within an average of <3 h and the remaining 33.3% (5/15) had the opposite-spectrum organism identified by culture growth. CONCLUSIONS: Polymicrobial mixed-spectrum cultures accounted for <5% of positive blood cultures and most isolates were identified within 3 h of first positivity. This may allow for further investigation of early de-escalation of therapy for this population and limit antimicrobial exposure.

Clinical utility of multiplex PCR in the detection of pathogens from sterile body fluids.

Rapid identification of pathogens in normally sterile body fluid (NSBF) is essential for appropriate patient management, specifically antimicrobial therapy. Limited sensitivity and increased time to detection of traditional culture prompted us to evaluate additional testing to contribute to the diagnosis of infection. The purpose of this study was to evaluate the GenMark Dx ePlex Blood Culture Identification (BCID) Panels on positive body fluids inoculated into blood culture bottles for the detection of microorganisms. A total of 88 positive body fluids from blood culture bottles were analyzed using a Gram-Positive, Gram-Negative, and/or Fungal pathogen BCID Panel based on the Gram stain result. Each result was compared to routine culture performed from the positive bottle. When using culture as a reference standard, we found the ePlex multiplex panel performed with a positive percent agreement of 96.5% and a negative percent agreement of 99.8%. The use of multiplex PCR may be a useful supplement to routine culture for NSBF in blood culture bottles. IMPORTANCE: The identification of pathogens in normally sterile body fluid (NSBF) is performed using routine culture, the current gold standard. Limitations of this method include sensitivity and increased turnaround times which could potentially delay vital patient care, especially antimicrobial therapy. Adaptations of NSBF in blood culture bottles prompted us to consider the utility of additional methods to bridge the gap in diagnostic challenges for these life-threatening infections. Multiplex molecular panels have been manufactured for use with multiple specimen types including blood, cerebral spinal fluid, stool, and respiratory. Therefore, the purpose of this study was to evaluate the off-label use of ePlex Blood Culture Identification Panels on positive body fluids grown in blood culture bottles for the detection of microorganisms for research purposes.

Disinfection of Neonatal Resuscitation Equipment in Low-Resource Settings: The Importance, the Reality, and Considerations for the Future.

Preventable neonatal deaths due to prematurity, perinatal events, and infections are the leading causes of under-five mortality. The vast majority of these deaths are in resource-limited areas. Deaths due to infection have been associated with lack of access to clean water, overcrowded nurseries, and improper disinfection (reprocessing) of equipment, including vital resuscitation equipment. Reprocessing has recently come to heightened attention, with the COVID-19 pandemic bringing this issue to the forefront across all economic levels; however, it is particularly challenging in low-resource settings. In 2015, Eslami et al. published a letter to the editor in Resuscitation, highlighting concerns about the disinfection of equipment being used to resuscitate newborns in Kenya. To address the issue of improper disinfection, the global health nongovernment organization PATH gathered a group of experts and, due to lack of best-practice evidence, published guidelines with recommendations for reprocessing of neonatal resuscitation equipment in low-resource areas. The guidelines follow the gold-standard principle of high-level disinfection; however, there is ongoing concern that the complexity of the guideline would make feasibility and sustainability difficult in the settings for which it was designed. Observations from hospitals in Kenya and Malawi reinforce this concern. The purpose of this review is to discuss why proper disinfection of equipment is important, why this is challenging in low-resource settings, and suggestions for solutions to move forward.

Predicting Oral Beta-lactam susceptibilities against Streptococcus pneumoniae.

BACKGROUND: Oral beta-lactam antimicrobials are not routinely tested against Streptococcus pneumoniae due to presumed susceptibility based upon penicillin minimum inhibitory concentration (MIC) testing. Currently, Clinical and Laboratory Standards Institute provides comments to use penicillin MIC ≤0.06 to predict oral cephalosporin susceptibility. However, no guidance is provided when cefotaxime MIC is known, leading to uncertainty with interpretation. The purpose of this study was to evaluate cefotaxime and penicillin MICs and their respective correlation to oral beta-lactam categorical susceptibility patterns. METHODS: 249 S. pneumoniae isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF) and then tested by broth microdilution method to penicillin, cefotaxime, amoxicillin, cefdinir, cefpodoxime, and cefuroxime. RESULTS: Using Clinical and Laboratory Standards Institute (CLSI) non-meningitis breakpoints for cefotaxime, 240/249 isolates were classified as susceptible. Of the cefotaxime susceptible isolates, 23% of the isolates are misrepresented as cefdinir susceptible. Amoxicillin correlated well with penicillin MIC breakpoints with only 1 discordant isolate out of 249. CONCLUSION: The correlation between amoxicillin and penicillin creates a very reliable predictor to determine categorical susceptibility. However oral cephalosporins were not well predicted by either penicillin or cefotaxime leading to the possible risk of treatment failures. Caution should be used when transitioning to oral cephalosporins in cefotaxime susceptible isolates, especially with higher cefotaxime MICs.

AB569, a non-toxic combination of acidified nitrite and EDTA, is effective at killing the notorious Iraq/Afghanistan combat wound pathogens, multi-drug resistant Acinetobacter baumannii and Acinetobacter spp.

Multi-drug resistant (MDR) Acinetobacter baumannii (Ab) and Acinetobacter spp. present monumental global health challenges. These organisms represent model Gram-negative pathogens with known antibiotic resistance and biofilm-forming properties. Herein, a novel, nontoxic biocide, AB569, consisting of acidified nitrite (A-NO2-) and ethylenediaminetetraacetic acid (EDTA), demonstrated bactericidal activity against all Ab and Acinetobacter spp. strains, respectively. Average fractional inhibitory concentrations (FICs) of 0.25 mM EDTA plus 4 mM A-NO2- were observed across several clinical reference and multiple combat wound isolates from the Iraq/Afghanistan wars. Importantly, toxicity testing on human dermal fibroblasts (HDFa) revealed an upper toxicity limit of 3 mM EDTA plus 64 mM A-NO2-, and thus are in the therapeutic range for effective Ab and Acinetobacter spp. treatment. Following treatment of Ab strain ATCC 19606 with AB569, quantitative PCR analysis of selected genes products to be responsive to AB569 revealed up-regulation of iron regulated genes involved in siderophore production, siderophore biosynthesis non-ribosomal peptide synthetase module (SBNRPSM), and siderophore biosynthesis protein monooxygenase (SBPM) when compared to untreated organisms. Taken together, treating Ab infections with AB569 at inhibitory concentrations reveals the potential clinical application of preventing Ab from gaining an early growth advantage during infection followed by extensive bactericidal activity upon subsequent exposures.

Combined Molecular and Phenotypic Antimicrobial Susceptibility Testing Is Beneficial in Detection of ESBL and AmpC Beta-Lactamase Producing Isolates of Enterobacteriaceae in Pediatric Patients with Bloodstream Infections.

Objectives: The aim was to assess the potential advantage of combined genotypic testing with phenotypic antimicrobial susceptibility testing (AST) to detect AmpC ß-lactamases (AmpC) and extended-spectrum ß-lactamases (ESBL) producing Enterobacteriaceae isolated from blood cultures in a pediatric population. Materials and Methods: All first-time Enterobacteriaceae isolates recovered from blood cultures of pediatric patients at the Cincinnati Children's Hospital Medical Center between January 2017 and December 2018 were evaluated. The Check-MDR CT103XL ß-lactamase assay was used to determine the presence of AmpC and ESBL, while AST was performed using the VITEK 2 platform. Phenotypic ESBL resistance was defined by resistance to either ceftriaxone or ceftazidime using Clinical and Laboratory Standards Institute breakpoints, while combined cefoxitin resistance with ceftriaxone or ceftazidime resistance was used to detect AmpCs (as per European Committee on Antimicrobial Susceptibility Testing standards). Results: Overall, there were 170 isolates. Genotypically, 21 (12.4%) had AmpC and 18 (10.6%) had ESBL genes detected. Phenotypically, 11 (6.5%) isolates were AmpC and 26 (15.3%) were ESBL producing organisms. Genotypic testing identified an additional 14 AmpC and two ESBL isolates that failed to meet phenotypic criteria. Conclusions: Using combined genotypic and phenotypic methods to detect AmpC and ESBL producing organisms increased the identification of resistant organism and provided potentially clinical relevant data to guide the treatment of resistant organisms.

AB569, a nontoxic chemical tandem that kills major human pathogenic bacteria.

Antibiotic-resistant superbug bacteria represent a global health problem with no imminent solutions. Here we demonstrate that the combination (termed AB569) of acidified nitrite (A-NO2-) and Na2-EDTA (disodium ethylenediaminetetraacetic acid) inhibited all Gram-negative and Gram-positive bacteria tested. AB569 was also efficacious at killing the model organism Pseudomonas aeruginosa in biofilms and in a murine chronic lung infection model. AB569 was not toxic to human cell lines at bactericidal concentrations using a basic viability assay. RNA-Seq analyses upon treatment of P. aeruginosa with AB569 revealed a catastrophic loss of the ability to support core pathways encompassing DNA, RNA, protein, ATP biosynthesis, and iron metabolism. Electrochemical analyses elucidated that AB569 produced more stable SNO proteins, potentially explaining one mechanism of bacterial killing. Our data implicate that AB569 is a safe and effective means to kill pathogenic bacteria, suggesting that simple strategies could be applied with highly advantageous therapeutic/toxicity index ratios to pathogens associated with a myriad of periepithelial infections and related disease scenarios.

Chlamydia Conjunctivitis in 2 Prepubertal Children: An Uncommon Presentation of Child Sexual Abuse.

Sexually transmitted infection as the result of child sexual abuse in prepubertal children is uncommon. Chlamydia trachomatis conjunctivitis is an even less common entity in prepubertal children outside the newborn period. This report details the presentation of 2 children with conjunctivitis who were subsequently diagnosed as having C. trachomatis conjunctivitis. One child was also diagnosed as having rectal and pharyngeal C. trachomatis infection, and the other also had genital C. trachomatis infection. Even with multisite C. trachomatis infection as an indication of sexual abuse, neither child gave a detailed disclosure of abuse to account for their infections. The absence of a clear disclosure is not uncommon. Previous literature reports that a disclosure in these circumstances occurs in less than half of cases. In this report, we review the recommendations for diagnosis of C. trachomatis using nucleic acid amplification testing and culture as well as treatment. Specific clinical features should alert the clinician to C. trachomatis conjunctivitis and lead to timely diagnosis and protection of the child from further sexual abuse.

Accelerating Initiation of Adequate Antimicrobial Therapy Using Real-Time Decision Support and Microarray Testing.

INTRODUCTION: Bloodstream infections (BSI) represent a common cause of sepsis and mortality in children. Early and adequate empirical antimicrobial therapy is a critical component of successful treatment of BSI. Rapid PCR-based diagnostic technologies, such as nucleic acid microarrays, can decrease the time needed to identify pathogens and antimicrobial resistance and have the potential to ensure patients are started on adequate antibiotics as early as possible. However, without appropriate processes to support timely and targeted interpretation of these results, these advantages may not be realized in practice. METHODS: Our Antimicrobial Stewardship Program (ASP) implemented a quality improvement initiative using the Institute for Healthcare Improvement's Model for Improvement to decrease the time between a nucleic acid microarray result for Gram-positive bacteremia and the time a patient was placed on adequate antimicrobial therapy. The primary effective intervention was a near real-time notification system to the managing physicians of inadequate antimicrobial therapy via a call from the ASP team. RESULTS: Following the intervention, the average time to adequate antimicrobial therapy in patients with Gram-positive BSI and inadequate coverage decreased from 38 hours with the nucleic acid microarray result alone to 4.7 hours when results were combined with an ASP clinical decision support intervention, an 87% reduction. CONCLUSIONS: The positive effects of rapid-detection technologies to improve patient care are enhanced when combined with clinical decision support tools that can target inadequate antimicrobial treatments in near real time.

Association of systemic antimicrobials with the expression of beta-lactamases in bacteria cultured from urological patients.

BACKGROUND: Patients with abnormalities of the genitourinary tract are at high risk for infections with antimicrobial-resistant pathogens. METHODS: All urine cultures ordered by members of the Division of Urology from four quarterly one-week periods were included. All gram-negative bacilli isolated were analyzed using the Check-Points Check-MDR CT103XL assay to identify the presence of genes associated with resistance to beta-lactam antibiotics. Association between the days of antibiotics and the presence of an ESBL-producing organism was determined. RESULTS: One hundred eleven positive cultures were included in this analysis, of which 5 (4.5%) contained ESBL-producing species. Days of systemic antibiotics within 30 days of urine culture was associated with an increased risk of isolating an ESBL-producing pathogen. CONCLUSION: The overall prevalence of ESBL-producing organisms is low in this cohort. The number of days of systemic antibiotics within 30 days of a urine culture was significantly associated with increased risk of isolating an ESBL-producing organism.

Evaluation of alternate parasite transport systems for the BD MAX™ enteric parasite panel.

Total-Fix, Cary-Blair, and Para-Pak SVT parasite transport systems were compared to 10% formalin with the BD MAX Enteric Parasite Panel, using clinical and contrived samples to determine comparability and limits of detection. The three transport systems have equal or superior limits of detection for all pathogens tested compared to 10% formalin.

The gut-liver axis: impact of a mouse model of small-bowel bacterial overgrowth.

BACKGROUND: The mechanisms by which intestinal bacteria impact liver diseases remain poorly understood. The aim of this study was to develop a mouse model of small-bowel bacterial overgrowth and to determine its impact on hepatobiliary injury. MATERIALS AND METHODS: A jejunal self-filling blind loop (SFBL) was created in C57BL/6 mice. Three weeks after surgery, the mice were euthanized, and bacterial cultures of luminal content of the loop and extraintestinal tissues were performed. Liver and jejunum were collected for histological grading of inflammation and injury. Serum liver biochemistry assays were performed. Hepatobiliary transporter mRNA expression in liver was measured by quantitative real-time polymerase chain reaction. Bile and blood were collected for measurement of total bile acids, phospholipid, and cholesterol. Mice undergoing jejunal transection and reanastomosis and laparotomy only served as control groups. RESULTS: SFBL induced a dramatic increase in intraluminal bacterial counts, mesenteric lymph node bacterial translocation, and evidence of jejunal and hepatobiliary injury. Significant reductions in hepatic expression of hepatobiliary transporters involved in biliary canalicular export and basolateral uptake were observed in SFBL mice. SFBL resulted in a significant increase in biliary total bile acid concentration, decreases in bile phospholipid and cholesterol output, and an increase in the bile acid/phospholipid ratio. CONCLUSIONS: We have developed a reproducible mouse model of small-bowel bacterial overgrowth with evidence of liver inflammation, altered hepatobiliary transporter expression, and alterations in bile composition. This model may help to elucidate the mechanisms by which gut-derived bacterial factors impact the liver and contribute to the exacerbation of liver diseases and biliary injury.

Frequency of Multidrug-Resistant Organisms Cultured From Urine of Children Undergoing Clean Intermittent Catheterization.

BACKGROUND: Children undergoing CIC frequently have positive urine culture results and receive many antimicrobial agents. Subsequently, this population is at high risk for infections caused by antimicrobial-resistant bacteria. Resistant pathogens, such as vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Enterobacteriaceae (CRE), and organisms that produce extended-spectrum ß-lactamases (ESBLs), which are third-generation cephalosporin resistant (3GCR), are of particular concern. METHODS: In this retrospective study, all urine culture results and antimicrobial-susceptibility testing results were obtained between January 2008 and December 2014 from the electronic health record of children ≤18 years of age who were undergoing CIC (n = 14 832). Isolates were identified as VRE, CRE, or 3GCR. Organisms of the same type that were obtained in the same year and with identical antibiotic susceptibilities from the same patient were excluded. Simple linear regression was used to determine the association between year and rates of resistance. RESULTS: A total of 3997 positive culture results were included in this analysis. Of all Enterococcus isolates for which susceptibility results were available, 4.6% were VRE, 11.1% of all isolates that belonged to the Enterobacteriaceae family were 3GCR, and 0.4% of eligible isolates were CRE. There were significantly higher rates of resistance to third-generation cephalosporins and CRE in 2014 than in 2008 (P < .01). Simple linear regression revealed a significant association between year and rate for resistance to third-generation cephalosporins but not for CRE or VRE. The rate of increase in resistance to third-generation cephalosporins in patients who required CIC was higher than that in patients who did not need CIC. CONCLUSIONS: The rate of resistance to third-generation cephalosporins has increased significantly in the past 7 years in children undergoing CIC, which indicates that careful monitoring is warranted for continued increases in antimicrobial-resistant organisms in this unique patient population.

Performance of the check-points check-MDR CT103XL assay utilizing the CDC/FDA antimicrobial resistance isolate bank.

The Check-MDR CT103XL beta-lactamase assay was validated for use in the clinical microbiology laboratory using two CDC-FDA Antimicrobial Resistant Isolate Bank panels (133 gram-negative bacilli known beta-lactamase genes). The CT103XL detected most reported resistance genes (123 of 136 genes) and additionally identified several resistance genes not reported by the CDC. Discrepant results were confirmed via whole genome sequencing.

Utilizing BD MAX™ Enteric Bacterial Panel to Detect Stool Pathogens from Rectal Swabs.

BACKGROUND: The BD MAX™ Enteric Bacterial Panel (BDM-EBP) is designed and FDA-cleared to detect Salmonella, Shigella, Campylobacter, and Shiga toxin genes stx1/2 from stool samples. However, rectal swabs, which are not FDA-cleared for clinical testing with the BDM-EBP, are common specimens received from pediatric patients for enteric pathogen testing. The purpose of this study was to evaluate the ability of the BDM-EBP to detect stool pathogens from rectal swabs. METHODS: Routine cultures, Shiga toxin testing, and molecular testing with BDM-EBP were performed on 272 sequential rectal swabs collected from August 2015 to December 2015. Discrepant test results were resolved using Verigene® Enteric Pathogens Nucleic Acid Test (EP). 36 challenge samples (13 Salmonella spp., 3 Shigella spp., 10 Campylobacter spp., and 10 Shiga toxin positive Escherichia coli) were tested using reference strains (American Type Culture Collection) and previous patient isolates diluted to103-104 cfu/ml in saline then added to Sample Buffer Tube (SBT) with negative stool matrix delivered via a swab. Limit of detection testing was performed by serial 10 fold dilutions in saline then added to SBT with negative stool matrix provided via a swab. RESULTS: A total of 272 rectal swab specimens were evaluated and 89 were positive by culture and/or MAX EBP. All discrepant results were BDM-EBP positive and culture negative. 21 of 31 (68%) of the apparent false positive BDM-EBP discrepant results resolved as positive with Nanosphere's Verigene® EP. After resolution of the discordant results, the Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA) are as follows for each target: Salmonella (n = 4) 100%, PPA and 100%, NPA; Shigella (n = 79) 100%, PPA and 95.3%, NPA; Campylobacter (n = 4) 100%, PPA and 99.6%, NPA; and Shiga toxin producing organisms (n = 2) 100%, PPA and 100%, NPA. 8.8% of the patient samples did not initially yield a result on the BDM-System. Upon repeat, half of the problematic samples resolved, and 4.4% of the total specimen tested did not yield a result. All organisms in the challenge samples were detected. Limits of detection for BDM-EBP testing of rectal swabs were as follows (in cfu/ml in SBT): Salmonella-1.44 × 102; Shigella-5.10 × 100; Campylobacter-1.51 × 101; and Shiga Toxin-1.13 ×103. CONCLUSION: Rectal swabs are acceptable samples for detecting Salmonella, Shigella, Campylobacter, and Shiga toxin using BDM-EBP.

Characterisation of carbapenem-resistant Enterobacteriaceae from the southwestern Ohio, northern Kentucky and southeastern Indiana region.

Although carbapenem-resistant Enterobacteriaceae (CRE) have been recognised worldwide, there are important gaps in regional prevalence data. This study sought to determine the occurrence and type of CRE in the Cincinnati tri-state region. Clinical microbiology laboratories in the region screened patient stool and rectal swab samples using chromogenic screening agar. Isolates of Enterobacteriaceae resistant to carbapenems were characterised using molecular methods. Area institutions screened 1939 patient samples. Of 18 Enterobacteriaceae that grew on the screening agar, 8 isolates were resistant to one or all carbapenems and 6 isolates (all Klebsiella spp.) tested positive for a blaKPC gene. This study provides guidance on the prevalence of KPC and the genetic characteristics of carbapenem-resistant Klebsiella pneumoniae isolates in the Cincinnati tri-state area. Additional similar local epidemiology studies are warranted to provide an understanding and control of the spread of CRE.

Extraction of total nucleic acids from bacterial isolates using the bioMérieux NucliSENS easyMAG total nucleic acid extractor.

The BioMerieux NucliSENS easyMAG total nucleic acid extractor was evaluated for use on bacterial isolates in the clinical microbiology laboratory. Forty eight isolates were extracted, yielding quantifiable amounts of DNA for all isolates. The easyMAG is appropriate for DNA extraction from bacterial isolates and will be incorporated in the clinical laboratory.

Pediatric bacteremia caused by Chromobacterium haemolyticum/Chromobacterium aquaticum.

We present a case of pediatric bacteremia caused by Chromobacterium haemolyticum, a ß-hemolytic, non-pigmented, Gram-negative bacilli recovered from a blood culture and initially identified as Chromobacterium violaceum using phenotypic and proteomic methods. 16S rRNA sequencing of the patient isolated demonstrated a high degree of sequence homology with the type strain of C. haemolyticum. The patient recovered following treatment with meropenem, gentamicin, and trimethoprim/sulfamethoxazole. This case highlights the potential misidentification of C. haemolyticum as non-pigmented C. violaceum due to limitations of the currently available identification methodologies.

A Putative ABC Transporter Permease Is Necessary for Resistance to Acidified Nitrite and EDTA in Pseudomonas aeruginosa under Aerobic and Anaerobic Planktonic and Biofilm Conditions.

Pseudomonas aeruginosa (PA) is an important airway pathogen of cystic fibrosis and chronic obstructive disease patients. Multiply drug resistant PA is becoming increasing prevalent and new strategies are needed to combat such insidious organisms. We have previously shown that a mucoid, mucA22 mutant PA is exquisitely sensitive to acidified nitrite ([Formula: see text], pH 6.5) at concentrations that are well tolerated in humans. Here, we used a transposon mutagenesis approach to identify PA mutants that are hypersensitive to [Formula: see text]. Among greater than 10,000 mutants screened, we focused on PA4455, in which the transposon was found to disrupt the production of a putative cytoplasmic membrane-spanning ABC transporter permease. The PA4455 mutant was not only highly sensitive to [Formula: see text], but also the membrane perturbing agent, EDTA and the antibiotics doxycycline, tigecycline, colistin, and chloramphenicol, respectively. Treatment of bacteria with [Formula: see text] plus EDTA, however, had the most dramatic and synergistic effect, with virtually all bacteria killed by 10 mM [Formula: see text], and EDTA (1 mM, aerobic, anaerobic). Most importantly, the PA4455 mutant was also sensitive to [Formula: see text] in biofilms. [Formula: see text] sensitivity and an anaerobic growth defect was also noted in two mutants (rmlC and wbpM) that are defective in B-band LPS synthesis, potentially indicating a membrane defect in the PA4455 mutant. Finally, this study describes a gene, PA4455, that when mutated, allows for dramatic sensitivity to the potential therapeutic agent, [Formula: see text] as well as EDTA. Furthermore, the synergy between the two compounds could offer future benefits against antibiotic resistant PA strains.