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Treatment of wounded military personnel at military medical centers is often complicated by colonization and infection of wounds with pathogenic bacteria. These include nosocomially transmitted, often multidrug-resistant pathogens such as Acinetobacter baumannii-calcoaceticus complex, Pseudomonas aeruginosa and extended spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae. We analyzed the efficacy of multivalent adhesion molecule (MAM) 7-based anti-adhesion treatment of host cells against aforementioned pathogens in a tissue culture infection model. Herein, we observed that a correlation between two important hallmarks of virulence, attachment and cytotoxicity, could serve as a useful predictor for the success of MAM7-based inhibition against bacterial infections. Initially, we characterized 20 patient isolates (five from each pathogen mentioned above) in terms of genotypic diversity, antimicrobial susceptibility and important hallmarks of pathogenicity (biofilm formation, attachment to and cytotoxicity toward cultured host cells). All isolates displayed a high degree of genotypic diversity, which was also reflected by large strain-to-strain variability in terms of biofilm formation, attachment and cytotoxicity within each group of pathogen. Using non-pathogenic bacteria expressing MAM7 or latex beads coated with recombinant MAM7 for anti-adhesion treatment, we showed a decrease in cytotoxicity, indicating that MAM7 has potential as a prophylactic agent to attenuate infection by multidrug-resistant bacterial pathogens.

BACKGROUND: Influenza-like illnesses (ILIs) are common in military populations, particularly among trainees, and can impair mission-readiness. To develop effective preventive measures against ILIs, it is vital to understand the ILI burden in the military population and identify potential risk factors for infection. METHODS: Anonymous ILI surveys were administered from January 2017 to March 2019 to military medical trainees living in a congregated setting on Fort Sam Houston (JBSA-FSH), TX. The surveys included questions about sociodemographic characteristics, weight, height, smoking status, activity level, as well as some basic questions about ILI and potential risk factors. Factors associated with ILI were identified using chi-square, t-tests, and multivariate models. RESULTS: 2,381 surveys were returned that included age, sex, and ILI information. Respondents were 16–54 years old, 1,301 (55%) were male, 782 (33%) were Air Force, 817 (34%) were Army, and 763 (32%) were Navy/Marines. 39% of those surveyed (929) reported having experienced an ILI during their training with 40% (370) seeking healthcare for those symptoms. The primary reasons for seeking healthcare included the severity of the illness (59%), concern about spreading the illness (50%), and the accessibility of healthcare (41%). 53% of the respondents reported that ILI had an impact on their performance, among whom 77% stated reduced study time, 66% missing physical training, and 53% missed class. The final multivariate model indicates that men and participants 30+ years old were less likely to report ILI (OR 0.69 (0.58, 0.82); OR 0.65, (0.45, 0.94)) (Figure 1). In addition, participants who reported washing their hands after they coughed or sneezed were less likely to report having had an ILI (OR 0.73 (0.61, 0.89)). CONCLUSION: Although 39% of respondents reported having an ILI during their training, only 40% sought healthcare, indicating that ILIs are more common during training than healthcare records indicate. More information is needed regarding ...

Abstract Background Biofilms are associated with persistent infection. Reports characterizing clinical infectious outcomes and patient risk factors for colonization or infection with biofilm forming isolates are scarce. Our institution recently published a study examining the biofilm forming ability of 205 randomly selected clinical isolates. This present study aims to identify potential risk factors associated with these isolates and assess clinical infectious outcomes. Methods 221 clinical isolates collected from 2005 to 2012 and previously characterized for biofilm formation were studied. Clinical information from the associated patients, including demographics, comorbidities, antibiotic usage, laboratory values, and clinical infectious outcomes, was determined retrospectively through chart review. Duplicate isolates and non-clinical isolates were excluded from analysis. Associations with biofilm forming isolates were determined by univariate analysis and multivariate analysis. Results 187 isolates in 144 patients were identified for analysis; 113 were biofilm producers and 74 were not biofilm producers. Patients were primarily male (78 %) military members (61 %) with combat trauma (52 %). On multivariate analysis, the presence of methicillin-resistant Staphylococcus aureus ( p < 0.01, OR 5.09, 95 % CI 1.12, 23.1) and Pseudomonas aeruginosa ( p = 0.02, OR 3.73, 95 % CI 1.46, 9.53) were the only characteristics more likely to be present in the biofilm producing isolate group. Infectious outcomes of patients with non-biofilm forming isolates, including cure, relapse/reinfection, and chronic infection, were similar to infectious outcomes of patients with biofilm-forming isolates. Mortality with initial infection was higher in the biofilm producing isolate group (16 % vs 5 %, p = 0.01) but attributable mortality was low (1 of 14). No characteristics examined in this study were found to be associated with relapse/reinfection or chronic infection on multivariate analysis. Conclusions Bacteria species, but not clinical characteristics, were associated with biofilm formation on multivariate analysis. Biofilm forming isolates and non-biofilm forming isolates had similar infectious outcomes in this study.

Background: Combat-related extremity wound infections can complicate the recovery of injured military personnel. The Enterococcus genus contains both commensal and pathogenic bacteria found in many combat wounds. We describe the patient population susceptible to Enterococcus infection, the characteristics of Enterococcus spp. isolated from combat-related wounds, and the microbiological profile of Enterococcus-positive wounds.

Leptospirosis may be caused by > 250 Leptospira serovars. Serovar classification is a complex task that most laboratories cannot perform. We assessed the interlaboratory reproducibility of a pulsed-field gel electrophoresis (PFGE) identification technique developed by the Centers for Disease Control and Prevention (CDC). Blinded exchange of 93 Leptospiraceae strains occurred between San Antonio Military Medical Center (SAMMC) and the CDC. PFGE was performed and gel images were analyzed and compared with patterns present in each laboratory's database (CDC database: > 800 strain patterns; SAMMC database: > 300 strain patterns). Overall, 93.7% (74 of 79) of strains present in each receiving laboratory's database were correctly identified. Five isolates were misidentified, and two isolates did not match serovar PFGE patterns in the receiving laboratory's database. Patterns for these seven isolates were identical between laboratories; four serovars represented misidentified reference strains. The PFGE methodology studied showed excellent interlaboratory reproducibility, enabling standardization and data sharing between laboratories.

Multidrug-resistant organisms (MDROs) are a global health problem that impact both civilian and military populations. Among wounded warriors, MDROs further complicate the care of trauma-related infections, resulting in extended duration of hospitalization, as well as increased morbidity and mortality. During the wars in Iraq and Afghanistan, extended spectrum β-lactamase-producing Enterobacteriaceae were frequently isolated from wounded warriors. The potential emergence of difficult-to-treat carbapenem-resistant Enterobacteriaceae represented a serious challenge for clinicians. We examined carbapenem-resistant Enterobacteriaceae prevalence among wounded military personnel over a six-year period (2009–2015). Among 4090 Enterobacteriaceae isolates collected, 16 (0.4%) were carbapenem-resistant, of which the majority was Enterobacter aerogenes (44%) followed by Klebsiella pneumoniae (37%), and Escherichia coli (19%). Five isolates (31%) collected from two patients were carbapenemase-producers with one associated with an infection. All five carbapenemase-producing isolates were resistant to all tested carbapenems and each carried one carbapenemase gene (4 with blaKPC-3 and 1 with blaNDM-1). Overall, although a large number of Enterobacteriaceae isolates were collected, only a small proportion was carbapenem-resistant and data indicate a lack of a cluster. Due to these limited numbers, it is difficult to make any conclusions regarding the association between carbapenem resistance, antibiotic exposure, and clinical outcomes.

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.

Background: The contribution of multi-drug–resistant gram-negative bacilli infections (MDRGN-I) in patients with trauma is not well described. We present characteristics of MDRGN-Is among military personnel with deployment-related trauma (2009–2014).

A total of 102 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from 50 injured service members (June 2009 to December 2011) at U.S. military treatment facilities were analyzed for the conventional mecA gene and mecC homologue by using standard PCR-based methods. The prevalence of the mecC homologue was zero.

Infections with multidrug-resistant Acinetobacter baumannii-Acinetobacter calcoaceticus complex bacteria complicate the care of U.S. military personnel and civilians worldwide. One hundred thirty-three isolates from 89 patients at our facility during 2006 and 2007 were tested by disk diffusion, Etest, and broth microdilution for susceptibility to tetracycline, doxycycline, minocycline, and tigecycline. Minocycline was the most active in vitro, with 90% of the isolates tested susceptible. Susceptibilities varied significantly with the testing method. The acquired tetracycline resistance genes tetA, tetB, and tetA(39) were present in the isolates.

BACKGROUND: Bloodstream infections (BSI) are associated with both inpatient mortality and substantial morbidity in the United States. We sought to characterize the epidemiology of BSIs with ESKAPE pathogens on patients served by the United States Military Healthcare System (MHS), which actively prospectively captures clinical and microbiological data from US service members and their beneficiaries. METHODS: We performed a retrospective analysis of MHS patients with blood cultures positive for ESKAPE pathogens (E. faecium, S. aureus, K. pneumoniae, A. baumannii, P. aeruginosa, and Enterobacter spp.), as well as Neisseria gonorrhoeae and Raoultella spp. between January 2010 and December 2015. Microbiological data from the Navy and Marine Core Public Health Center was retrospectively collated with clinical and demographic data from the MHS Data Repository. RESULTS: We identified 7,404 patients who experienced 8,791 episodes of ESKAPE (including N. gonorrhoeae and Raoultella spp.) BSI. The patients were predominately active duty (N=688) or retired (N=2,517) Armed Forces service members and their dependents (N=2,361). Further, 59.4% were male and 47.5% were >65 years old. A total of 5,594 (75.5%) of BSI episodes were associated with hospital admission, with an average length of stay of 14.9 days (SD of 27.5 days) and 47.4% (N=2,650) of those admissions were associated with an ICU stay averaging 8.6 days (SD of 18.0 days). The most common pathogens detected were E. coli (34.6%, N= 3,042) followed by S. aureus (28.0%,N=2,464), with 7.6% and 40.7% of isolates resistant to ceftriaxone and methicillin, respectively. We found a larger proportion of E. coli BSI in females (47.4% versus 26.2%) and S. aureus BSI in males (32% versus 21.9%). The frequency of A. baumannii BSI in younger patients, ages 18-30, was an average 4.5 fold higher than in older age groups (30-50, 50-65 and >65). CONCLUSION: We noted epidemiological differences in the burden of ESKAPE pathogen BSIs, in various populations including sex and age ...

INTRODUCTION: During recent wars in Iraq and Afghanistan, improved survivability in severe trauma corresponded with a rise in the proportion of trauma-related infections, including those associated with multidrug-resistant organisms (MDROs). Significant morbidity was reported in association with the infections. There is also concern regarding potential long-term impacts of the trauma-related infectious complications. Therefore, to meet the critical need of prospective collection of standardized infection-related data to understand the disease burden and improve outcomes of wounded personnel, the Trauma Infectious Disease Outcomes Study (TIDOS) was developed. Herein, we review accomplishments and key peer-reviewed findings of TIDOS. METHODS: The TIDOS project is a multicenter observational study of short- and long-term infectious complications following deployment-related trauma. Wounded military personnel medevac'd to Landstuhl Regional Medical Center (LRMC; Germany) before transfer to a participating US military hospital between June 2009 and December 2014 were eligible for inclusion. An infectious disease module to supplement the Department of Defense Trauma Registry by collecting infection-related data from all trauma patients admitted to participating hospitals was developed. Specimens from trauma patients were also collected and retained in a microbiological isolate repository. During the initial hospitalization, patients were given the opportunity to enroll in a prospective follow-up cohort study. Patients who received Department of Veterans Affairs (VA) care were also given the opportunity to consent to ongoing VA follow-up RESULTS: A total of 2,699 patients transferred to participating military hospitals in the USA, of which 1,359 (50%) patients enrolled in the TIDOS follow-up cohort. In addition, 638 enrolled in the TIDOS-VA cohort (52% of TIDOS enrollees who entered VA healthcare). More than 8,000 isolates were collected from infection control surveillance and diagnostic evaluations and retained in the ...

Stenotrophomonas maltophilia is a pathogen with unique resistance patterns. We assessed 70 combat casualties with S. maltophilia clinical isolates to examine its role as a nosocomial pathogen in critically-ill trauma patients. Incidence density was 0.36 S. maltophilia infections per 100 patient-days (95% CI: 0.29–0.44). Patients predominantly had blast trauma (97%) and were critically injured (injury severity score [ISS] >25; 80%). Restricting to patients with ISS >15, 50 patients with S. maltophilia infections were compared to 441 patients with infections attributed to other gram-negative bacilli. Patients with S. maltophilia infections had significantly more operating room visits prior to isolation, traumatic or early surgical amputations, longer hospitalization (median 71 vs 47 days), and higher overall mortality (10% vs 2%; p=0.01). Initial and serial (≥7 days between initial and subsequent isolation) S. maltophilia isolates had high susceptibility to trimethoprim-sulfamethoxazole and minocycline. Evaluation of newer agents awaiting CLSI breakpoints, including moxifloxacin, showed promising results.

BACKGROUND: Recent work has argued that genus Klebsiella is best divided into 3 clades: K. pneumoniae (Kp), K. quasipneumoniae (Kq), and K. variicola (Kv). Kv has drawn attention from reports of higher mortality and virulence. We evaluated a previously defined group of military trauma patients with Klebsiella infections for the presence of Kv, described clinical and isolate characteristics, and compared Kv and Kp groups. METHODS: All initial and serial (≥7 days from prior isolate) infecting Kp isolates (identified by clinical laboratories without the ability to speciate Kq and Kv) were collected from the Trauma Infectious Disease Outcomes Study (6/09–12/14). Additionally, a previously defined group of colonizing isolates linked to the infecting isolates and a selection of random colonizers were included from groin swabs. DNA extraction and PCR targeting Kv per published methods was performed. Antimicrobial susceptibilities were determined using the BD Phoenix Automated Microbiology System and CLSI criteria. Multidrug resistance was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of ESBL or KPC. RESULTS: Of 237 archived Kp isolates (from 122 patients), 10 (4%) were identified as Kv by PCR (from 8 [7%] patients). The Kv sources were 4 from blood (40%), 1 intra-abdominal (10%) and 5 from groin (50%). Six (3%) isolates were identified as Kq (4 from groin and 2 from respiratory specimens). The Kv and Kp patients were all males, with a median age of 25 (IQR 21–46) and 23 (IQR 21–28), length of hospital stay of 24 days (IQR: 5–106) and 53 days (IQR 36–74), and Injury Severity Score of 21 (IQR: 10–50) and 38 (IQR: 30–45), respectively. There were no deaths in the Kv group compared with 4 with Kp. Infecting Kv isolates were more likely to be from blood compared with Kp (80% vs. 17%, P = 0.04). No infecting Kv isolates were multidrug-resistant compared with 70% of infecting Kp isolates (P < 0.01). CONCLUSION: Kv represented 4% of the previously ...

BACKGROUND: Biocides play an integral role in infection control. Paralleling concern about rising incidence of multidrug-resistant (MDR) organisms is a concern for resistance to biocides. In small studies, several genes involved in the production of efflux pump proteins have been identified as markers of biocide resistance in Klebsiella spp., namely cepA, qacA, qacE, qac∆E, and acrA. This study aimed to analyze the Klebsiella spp. isolates of a previously defined military trauma group with a high incidence of MDR organisms for the presence of these genes and their correlation with other resistance. METHODS: All infecting K. pneumoniae, K. variicola, and K. quasipneumoniae isolates archived by the Trauma Infectious Disease Outcomes Study (June 2009–December 2014) were selected. Additionally, all colonizing isolates linked with infecting isolates were included; the remainder to total 50 MDR and 46 non-MDR colonizing isolates were chosen randomly. Antimicrobial identification and susceptibilities were determined by CLSI criteria using the BD Phoenix Automated Microbiology System. PCR according to published methods for cepA, qacA, qacE, qac∆E, and acrA was accomplished in duplicate. MDR was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of an ESBL or KPC. RESULTS: A total of 237 isolates (221 K. pneumoniae, 10 K. variicola, 6 K. quasipneumoniae) met inclusion criteria, of which 149 (63%) were MDR. All isolates had been exposed to antimicrobials prior to isolation. Of all isolates, 234 (98%) carried cepA: 218 (98%) K. pneumoniae carried cepA, 10 (100%) K. variicola carried cepA, and 6 (100%) of K. quasipneumoniae carried cepA. In addition, 148 (62%) isolates with cepA were MDR. One (10%) K. variicola isolate carried qacE along with cepA. This isolate was the only MDR K. variicola. None of the isolates carried qacA, qac∆E, or acrA. CONCLUSION: We confirmed the near universal presence of the cepA biocide resistance gene in Klebsiella spp. ...