Development Of Clinical Infection Research Articles

Active Surveillance Cultures and Procalcitonin in Combination With Clinical Data to Guide Empirical Antimicrobial Therapy in Hospitalized Medical Patients With Sepsis.

ObjectiveThe prevalence of colonization with multidrug-resistant organisms (MDRO) has increased over the last decade, reaching levels as high as 23% in certain patient populations. Active surveillance cultures (ASC) represent a valuable tool to identify patients colonized with MDRO to apply preventive measures, reduce transmission, and guide empiric antimicrobial therapy. There is a paucity of data evaluating the impact of admission ASCs to predict future infection. The aim of this study was to evaluate the concordance between ASCs results and the development of clinical infection by the same microorganism identified in the surveillance swab (“swab-related infection”), in hospitalized septic patients, and to evaluate the presence of specific risk factors associated with the development of a swab-related infection.MethodsAll adults admitted to the Diagnostic and Therapeutic Medicine Department of the University Hospital Campus Bio-Medico of Rome with a diagnosis of infection or any other medical reason with admission surveillance swabs (rectal or nasal) between January 2018 and February 2021 were included in the study. A retrospective chart review was conducted to identify patients that developed infections with concordant MDROs identified on ASC, and the risk factors for swab-related infection. Secondary outcomes were need of intensive care unit transfer, length of stay, sepsis or septic shock development, and all-cause mortality.ResultsA total of 528 patients were included in the study, of which 97 (18.3%) had a positive surveillance swab. Among patients with positive surveillance swabs, 18 (18.5%) developed an infection with the same microorganism recovered from the swab, 57 (58.8%) developed an infection with a different microorganism than that recovered from the surveillance swab, and 22 (22.7%) did not develop an infection during hospitalization. The number of colonized sites, an interventional procedure within the previous 3 months, a Systemic Inflammatory Response Syndrome (SIRS) score ≥ 2, and a quick Sequential Organ Failure Assessment (q-SOFA) score ≥ 2 were associated with a significantly higher risk of developing a swab-related infection. SIRS and q-SOFA scores ≥ 2 and procalcitonin ≥ 0.43 ng/ml help for identifying patients with a swab-related infection.ConclusionPatients with positive surveillance swabs were at increased risk for development of infections by the same MDRO identified in surveillance swabs (swab-related infection). This study is the first to show that the positivity of surveillance swabs, in combination with anamnestic data, PCT values, and SIRS or q-SOFA scores, serves as a valuable tool to help clinicians predict patients at higher risk for swab-related infection development and guide the administration of appropriate empiric antimicrobial therapy in septic patients.

INFLUENCE OF PATIENT’S GENERAL HEALTH STATUS ON THE OUTCOME OF INFECTIONS

The outcomes of a pathogen colonization and development of clinical infection can be strictly related to the general health status of a patient. The spread of the awareness about the dangers of underlying health conditions should be the main role of the conventional medicine, as well as the key to successful treatments and control of diseases.

979. Getting Candid with Candida auris: Evaluation of Isolates at SBH Health System

Abstract Background Candida auris is a multidrug resistant yeast that was originally isolated in the external ear of a patient in Japan in 2009. Since then, it has rapidly spread throughout the world. C. auris is inherently a multidrug resistant organism, making echinocandins the drugs of choice. C. auris was first isolated in SBH in a wound culture in 2018, and it has become a major health concern. Our objectives were to evaluate our clinical C. auris isolates, identify potential risk factors for infection, and assess our susceptibilities to determine the most appropriate treatment option. Methods This was a retrospective chart review of all clinical isolates of C. auris from July 2018 – April 2021. Data collection included location prior to admission, SBH hospitalization within 90 days, hospital vs community acquired, new vs recurrent, specimen type, susceptibilities, and lines at the time of culture. Results A total of 121 clinical isolates were evaluated from 74 patients. Although initially clinical isolates were rare, prevalence increased in subsequent years, with 97 clinical isolates identified in 2020. Isolates were identified in various specimen types, with the majority in urine, respiratory samples, or blood cultures. 64% of the isolates were hospital onset. Among patients who tested positive for C. auris colonization through surveillance testing, 22% proceeded to develop clinical infections. Most of the patients with positive blood cultures had either one or multiple IV access points, which may be a risk factor for candidemia. All isolates were resistant to fluconazole, 87% were susceptible to amphotericin B, and susceptibility to echinocandins ranged from 98-99%. Susceptibilities Susceptibilities for the Candida auris clinical isolates received from the NYS Department of Health Specimen Type IV Access in Positive Blood Cultures Access points that were present at the time of candidemia Conclusion Candida auris is a persistent fungus that is highly contagious that has been increasing in prevalence. Infection control measures remain the most proven method to decrease the development of clinical infections. Our study has some limitations, such as the retrospective design, the lack of a control group, lack of clinical outcomes, and limited surveillance testing capabilities. C. auris remains a major cause of concern for nosocomial infections, particularly in patients with various indwelling catheters. Our susceptibilities confirmed echinocandins as the class of choice for treatment of C. auris infections. Disclosures Judith Berger, MD, Nothing to disclose

Safety of Contemporary Resorbable Fixation Systems for Craniofacial Reconstruction in Pediatric Patients.

Resorbable hardware allows adequate strength for maintaining the relative position of the craniofacial skeleton during osseous healing, and allowing subsequent growth in pediatric patients. The purpose of this study was to determine the complication profile of the latest copolymer of resorbable plates for craniofacial reconstruction in pediatric patients. Retrospective query of the operative billing record was performed for use of the DePuy Synthes Rapidsorb Fixation System at the authors' tertiary children's hospital from 2015 to 2019. Three hundred twenty-five patients were randomly selected for analysis of complications within the first postoperative year. Median age at craniofacial reconstruction was 3.0 years, with 127 procedures (39.9 percent) performed for an intracranial mass and 141 procedures (44.3 percent) performed for craniosynostosis. Overall, 7.9 percent patients had a postoperative wound complication. The most common complications were dehiscence (3.8 percent), hematoma/seroma (3.5 percent), and infection (2.5 percent). There were no instances of extrusion, plate fracture, or screw loosening. Hardware complications in the temporoparietal region were more likely to occur at incision sites (p = 0.001), whereas wound complications at the frontal region were more likely to occur away from incision sites (p < 0.001). There were no differences in complications between plates secured with resorbable screws or with the resorbable injectable polymer system (p ≥ 0.161 for all). Radiotherapy was significantly implicated in development of clinical infection (p = 0.001), culture-positive infection (p < 0.001), readmission (p = 0.007), reoperation (p = 0.003), and plate removal (p = 0.007). Resorbable cranial hardware has an overall favorable complication profile for craniofacial reconstruction in pediatric patients undergoing surgical intervention for craniosynostosis or intracranial mass resection.

Plasmid-Mediated Quinolone Resistance in Pseudomonas aeruginosa Isolated from Burn Patients in Tehran, Iran.

Plasmid-induced quinolone resistance has raised a great concern in the treatment of serious infections worldwide. The aims of this study were to determine the antibiotic susceptibility, the frequency of qepA, aac(6')-Ib and qnr genes by PCR and sequencing, and typing of the resistant isolates using repetitive extragenic palindromic sequence-based PCR (REPPCR) in Pseudomonas aeruginosa isolated from burn wound infections. In the current cross-sectional study, 149 P. aeruginosa were isolated from the burn wound samples of patients admitted to Motahari hospital in Tehran, Iran, from February to December 2016. The bacterial isolates were identified using standard laboratory methods and their antibiotic susceptibility to quinolones was evaluated using the standard Kirby-Bauer method, according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The presence of aac(6')-Ib, qepA, qnrA, qnrB4, qnrB and qnrS genes was assessed using PCR and sequencing methods and clonal relationship of the resistant isolates was evaluated using REP-PCR method. All (100%) isolates showed complete resistance to used quinolone compounds in this study. The qnr and qepA genes were not found, but all (100%) isolates were positive for the presence of aac(6')-Ib gene and the sequencing revealed that all (100%) belong to the aac(6')-Ib-cr variant. REP-PCR showed that the studied isolates belonged to three distinct clones of A (77.9%), B (18.1%), and C (4%). The findings of the present study indicated the presence of aac(6')-Ib-cr variant and lack of the contribution of qnr and qepA in the emergence of resistance to quinolones in P. aeruginosa isolated from burn patients. Considering the importance of clonal spread of these resistant isolates and their significant role in the development of clinical infections, especially in patients with burns, more attention should be paid to the prevention of the dissemination of these resistant isolates.

New Zealand rickettsia-like organism (NZ-RLO) and Tenacibaculum maritimum: Distribution and phylogeny in farmed Chinook salmon (Oncorhynchus tshawytscha).

A total of 777 fish from three growing regions of New Zealand Chinook salmon farms comprising of five sites were tested. Quantitative PCR was used to determine the distribution of New Zealand rickettsia-like organism and Tenacibaculum maritimum. Genetic information from these bacteria were then compared with strains reported worldwide. Using this information, suggested associations of pathogens with clinically affected fish were made. NZ-RLO was detected in two of the three regions, and T. maritimum was detected in all regions. Three strains of NZ-RLO were identified during this study. Based on analysis of the ITS rRNA gene, NZ-RLO1 appears to be part of an Australasian grouping sharing high similarity with the Tasmanian RLO, NZ-RLO2 was shown to be the same as an Irish strain, and NZ-RLO3 was shown be closely related to two strains from Chile. Based on multi-locus sequence typing, the New Zealand T. maritimum was the same as Australian strains. NZ-RLOs were detected more frequently in fish with skin ulcers than fish without skin ulcers. While additional research is required to investigate the pathogenicity of these organisms, this is the first time that NZ-RLOs have been associated with the development of clinical infections in farmed Chinook salmon.

Cytotoxic activity of Kingella kingae RtxA toxin depends on post-translational acylation of lysine residues and cholesterol binding

Kingella kingae is a member of the commensal oropharyngeal flora of young children. Improvements in detection methods have led to the recognition of K. kingae as an emerging pathogen that frequently causes osteoarticular infections in children and a severe form of infective endocarditis in children and adults. Kingella kingae secretes a membrane-damaging RTX (Repeat in ToXin) toxin, RtxA, which is implicated in the development of clinical infections. However, the mechanism by which RtxA recognizes and kills host cells is largely unexplored. To facilitate structure-function studies of RtxA, we have developed a procedure for the overproduction and purification of milligram amounts of biologically active recombinant RtxA. Mass spectrometry analysis revealed the activation of RtxA by post-translational fatty acyl modification on the lysine residues 558 and/or 689 by the fatty-acyltransferase RtxC. Acylated RtxA was toxic to various human cells in a calcium-dependent manner and possessed pore-forming activity in planar lipid bilayers. Using various biochemical and biophysical approaches, we demonstrated that cholesterol facilitates the interaction of RtxA with artificial and cell membranes. The results of analyses using RtxA mutant variants suggested that the interaction between the toxin and cholesterol occurs via two cholesterol recognition/interaction amino acid consensus motifs located in the C-terminal portion of the pore-forming domain of the toxin. Based on our observations, we conclude that the cytotoxic activity of RtxA depends on post-translational acylation of the K558 and/or K689 residues and on the toxin binding to cholesterol in the membrane.

Contaminação de enxertos de tendões flexores na reconstrução do ligamento cruzado anterior: comparação de duas técnicas de retirada

ObjectiveTo evaluate the contamination rate of hamstring tendon autograft by comparing two different techniques, and to verify whether intraoperative contamination is associated with clinical infection development in patients submitted to reconstruction of the anterior cruciate ligament. MethodsOne hundred and ten hamstring tendons autograft anterior cruciate ligament reconstructions were performed and divided into two groups: 1 – hamstring tendon retraction technique and 2 ‐ technique maintaining the tibial insertion of the hamstring tendon. During the preparation, two grafts fragments were sent for culturing; the harvesting time, preparation time, and total surgery time were measured. Twenty‐four hours after the surgery, the C‐reactive protein was assayed. Clinical outpatient follow‐up was performed up to 180 days postoperatively. ResultsAlthough there were two postoperative infections, there was no graft contamination or difference between the groups in relation to the graft preparation time and the 24‐hour post‐operative C‐reactive protein. The classic technique presented longer graft harvesting time (p = 0.038) and there was no statistical difference between the two groups regarding the degree of contamination and consequent clinical infection, although two patients in group 2 had infection with negative perioperative cultures. ConclusionBased on the results obtained, there was no association between graft contamination and the time or technique of its preparation. In addition, there was also no association between intraoperative contamination and development of clinical infection, nor was there any sign of an association between the early alteration of C‐reactive protein and the onset of infection.

Use of bacterial cultures in open wound fractures: A prospective cohort study

Introduction: Open fractures are a big challenge for surgeons to treat due to wound contamination leading to infection is a well established complication. To overcome this complication, prophylactic antibiotic therapy is routinely recommended for open fractures. Methods: A single center, prospective cohort study was conducted on patients at a tertiary care academic center to assess surgical site infection following fixation of upper and lower limb open fractures. In this study, we aimed to identify the utility of postdebridement cultures for predicting postoperative wound infection with the identification of association between the incidence of infection and factors such as age, gender, fracture site, cause of injury, and the time between injury and presentation at hospital. Results: Postdebridement cultures of 46 patients were collected, of which 28.3% showed microbial growth. During the hospital stay, three patients developed clinically deep wound infection. Postdebridement culture growth was not significantly associated with the development of clinical infection within the hospital stay (P = 0.188). Out of 43 remaining patients, 11 patients develop wound infection on follow up. Four out of 11 had positive growth on initial cultures. Conclusion: In this study, we evaluated that postdebridement wound cultures were not useful in predicting wound infection in the postoperative period.

Should We Immediately Start Antibiotics in Every Patient with a Clinical Suspicion of HAP/VAP?

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) remain two of the most commonly diagnosed nosocomial infections. Both are responsible for significant morbidity and mortality in hospitalized patients. The development of HAP and VAP is related to bacterial colonization of the oropharynx (and endotracheal tube in VAP) with subsequent microaspiration and development of clinical infection. Diagnosis is made based on the clinical presentation and can be confirmed by obtaining either noninvasive or invasive microbiology culture specimens. Decisions addressing initiation of antimicrobial therapy can be divided into clinical and bacteriological strategies. These strategies differ in the criteria used to determine the timing of empiric therapy, with the clinical strategy basing the decision on radiographic evidence of infection plus clinical signs and symptoms and the bacteriological strategy requiring growth of pathogens above a certain threshold from invasively obtained culture specimens. Despite the delineated pathways, these decisions remain multifactorial and should also include consideration of patient-related factors, such as immunocompetence, the risk of multidrug-resistant infection, and overall clinical condition. Patients with risk factors or signs of clinical decompensation should have empiric therapy initiated at a lower threshold. However, when possible, therapy should be directed at a confirmed infection following a positive culture result. Decisions regarding specific empiric regimens should be based on the local prevalence of infectious microorganisms along with their associated antimicrobial susceptibilities. Patients deemed at risk of infection with multidrug-resistant pathogens merit broader spectrum therapy, and immunosuppressed patients should have consideration of antifungal coverage.

Abstract T P317: Sepsis in Intracranial Hemorrhage: Does Stroke-Induced Systemic Immunosuppression Play a Role?

INTRODUCTION: Infection is a significant cause of mortality in patients with both ischemic and hemorrhagic stroke. This is thought to occur as a result of stroke-induced systemic immunosuppression (SIIS). The role of cerebral damage pre-disposing to sepsis has only been addressed in a few studies for ischemic stroke, and literature is sparse in Spontaneous Intracerebral Hemorrhage (SICH) patients who have higher mortality, greater disability and require more intensive medical care. We sought to determine identify predictors of SIIS and sepsis, so we may be able to recognize and intervene early. METHODOLOGY: We retrospectively analyzed 40 patients with SICH admitted to the NICU between January 2012 and January 30, 2014. We included patients with SICH. We excluded patients with multi-compartmental hemorrhage and patients lacking outcome data. Patient demographics including age, gender, location, volume of SICH, GCS, and total lymphocyte counts from days one to five of hospitalization was recorded. Data was divided into a non-infection group, where patients lacked any clinical or laboratory evidence of infections, and an infection group. Statistical analysis was performed to compare lymphocyte depletion over time between patients that developed an infection and those that did not. RESULTS: From the cohort of 40 patients with SICH, 20 developed an infection during their hospital course. Total lymphocyte counts were lower on all five days in the infection group compared to the non-infection group and became significant on day four of hospitalization (1 in the infection group vs. 2.1 in the non-infection group, p&lt;0.01. Lymphopenia preceded clinical signs and symptoms of infection, which occurred in average on day 5.8 of hospitalization. Patients in the infection group had greater hemorrhage volume (32.5 ml vs. 15.5 ml) and poorer GCS scores on admission (12.7 vs. 11.8) although these differences did not reach statistical significance. CONCLUSION: The incidence of sepsis is high in SICH patients, and these patients have worse prognostic parameters. Our data suggests identification of lymphopenia may be a significant predictor of development of clinical infection in these patients. Future studies with larger sample sizes are warranted.

Abstract W P425: Sepsis in Intracranial Hemorrhage: Does Stroke-Induced Systemic Immunosuppression Play a Role?

INTRODUCTION: Infection is a significant cause of mortality in patients with both ischemic and hemorrhagic stroke. This is thought to occur as a result of stroke-induced systemic immunosuppression (SIIS). The role of cerebral damage pre-disposing to sepsis has only been addressed in a few studies for ischemic stroke, and literature is sparse in Spontaneous Intracerebral Hemorrhage (SICH) patients who have higher mortality, greater disability and require more intensive medical care. We sought to determine identify predictors of SIIS and sepsis, so we may be able to recognize and intervene early. METHODOLOGY: We retrospectively analyzed 40 patients with SICH admitted to the NICU between January 2012 and January 30, 2014. We included patients with SICH. We excluded patients with multi-compartmental hemorrhage and patients lacking outcome data. Patient demographics including age, gender, location, volume of SICH, GCS, and total lymphocyte counts from days one to five of hospitalization was recorded. Data was divided into a non-infection group, where patients lacked any clinical or laboratory evidence of infections, and an infection group. Statistical analysis was performed to compare lymphocyte depletion over time between patients that developed an infection and those that did not. RESULTS: From the cohort of 40 patients with SICH, 20 developed an infection during their hospital course. Total lymphocyte counts were lower on all five days in the infection group compared to the non-infection group and became significant on day four of hospitalization (1 in the infection group vs. 2.1 in the non-infection group, p&lt;0.01. Lymphopenia preceded clinical signs and symptoms of infection, which occurred in average on day 5.8 of hospitalization. Patients in the infection group had greater hemorrhage volume (32.5 ml vs. 15.5 ml) and poorer GCS scores on admission (12.7 vs. 11.8) although these differences did not reach statistical significance. CONCLUSION: The incidence of sepsis is high in SICH patients, and these patients have worse prognostic parameters. Our data suggests identification of lymphopenia may be a significant predictor of development of clinical infection in these patients. Future studies with larger sample sizes are warranted.

The Effect of Reusable Versus Disposable Draping Material on Infection Rates in Implant-Based Breast Reconstruction

Clinical infection remains a significant problem in implant-based breast reconstruction and is a physical and emotional strain to the breast reconstruction patient. Bacterial strikethrough of draping and gown material is a likely source of infection. Strategies to reduce infection in implant-based breast reconstruction are essential to improve patient outcomes. The aim of this study is to determine if a disposable draping system is superior to reusable draping materials in the prevention of implant-based breast reconstruction infection. This single-institution, prospective, randomized, single-blinded, IRB-approved study enrolled women with breast cancer who were eligible for implant-based breast reconstruction. The primary endpoint was clinical infection by postoperative day 30. Secondary endpoints included all other complications encountered throughout the follow-up period and culture data. Demographic data recorded included patient age, body mass index, diabetes, smoking, chemotherapy, radiation, and follow-up. Procedural data recorded included procedure type, procedure length, estimated blood loss, use of acellular dermal matrix, use of muscle flap, and inpatient versus outpatient setting. From March 2010 through January 2012, 107 women were randomized and 102 completed the study. Five patients were determined not to be candidates for reconstruction after randomization. There were 43 patients in the Reusable Group and 59 patients in the Disposable Group. There were no significant differences in patient demographic data, procedural data, or the type of procedure performed between groups. In the Reusable Group, there were 5 infections (12%) within 30 days compared to 0 (0%) infections in the Disposable Group (P = 0.012). There was no significant difference in secondary complications. There was a trend for positive wound cultures (11% vs. 3%, P = 0.10) and positive drape cultures (17% vs.4%, P = 0.08) in patients with clinical infection. There were no differences in the number of colony-forming units or positive cultures between groups. Disposable draping material is superior to a reusable draping system in the prevention of clinical infection within the immediate postoperative period. This study did not demonstrate a clear link between intraoperative culture data and the development of clinical infection. A completely disposable gown and draping system is recommended during implant-based breast reconstruction.

Positive Cultures of Organ Preservation Fluid Predict Postoperative Infections in Solid Organ Transplantation Recipients

The significance of positive cultures of organ preservation fluid (OPF) in solid organ transplantation is not known. We sought to describe the microbiology and define the clinical impact of positive OPF cultures. Retrospective cohort study. Tertiary care hospital. A consecutive sample of all solid organ transplantations at our center between July 2006 and January 2009 was reviewed. A total of 331 allografts (185 kidneys, 104 livers, 31 pancreases, and 11 hearts) met the inclusion criterion of having OPF cultures taken from the transplanted allograft. Organisms recovered from OPF were classified as high or low risk according to their virulence. Clinical outcomes were compared between recipients of organs with positive OPF cultures and recipients of organs with negative OPF cultures. OPF cultures were positive in 62.2% of allografts and yielded high-risk organisms in 17.8%. Normal skin flora constituted the majority of positive OPF cultures, while Enterobacteriaceae spp. and Staphylococcus aureus made up the majority of high-risk organisms. Recipients of allografts with positive OPF cultures developed more frequent bacterial infections, regardless of allograft type (relative risk, 2.39; 95% confidence interval [CI], 1.61-3.54). Moreover, isolation of a given organism in OPF samples was associated with the development of a clinical infection with the same organism, regardless of allograft type. Positive cultures of OPF are common events in solid organ transplantation, frequently involve high-risk organisms, and are associated with the development of postoperative clinical bacterial infections. Further study is required to determine the optimal strategies for their prevention and management.

The classical complement pathway plays a critical role in the opsonisation of uropathogenic Escherichia coli

Urinary tract infection due to uropathogenic Escherichia coli is a common clinical problem. The innate immune system and the uroepithelium are critical in defence against infection. The complement system is both part of the innate immune system and influences the interaction between epithelium and pathogen. We have therefore investigated the mechanism by which uropathogenic E. coli activate complement and the potential for this to occur during clinical infection. The classical pathway is responsible for bacterial opsonisation when complement proteins are present at low concentrations. At higher concentrations the alternative pathway predominates but still requires the classical pathway for its initiation. In contrast the mannose binding lectin pathway is not involved. Early classical pathway components are present in the urine during infection and actively contribute to bacterial opsonisation. The classical pathway could be initiated by anti- E. coli antibodies of IgG or IgM subclasses that are present in urine during infection. Additionally immunoglobulin-independent mechanisms, such as direct C1q binding to bacteria, may be involved. In conclusion, uropathogenic E. coli are readily opsonised by complement in a classical pathway dependent manner. This can occur within the urinary tract during the development of clinical infection.

In Vivo Efficacy of Antimicrobial-Coated Devices

Since device colonization is a prelude to infection, an antimicrobial-coated device that reduces bacterial colonization can potentially protect against infection. The objective of this animal study was to assess the efficacy of a coating with minocycline and rifampin to prevent colonization of a grit-blasted titanium implant and subsequent osteomyelitis. Twenty-five rabbits underwent implantation of a titanium-alloy pin, either coated with minocycline and rifampin (thirteen rabbits) or uncoated (twelve rabbits), into the right femoral medullary canal. The implanted devices were inoculated with 500 CFU (colony-forming units) of Staphylococcus aureus prior to wound closure. The rabbits were killed one week later, and the removed device, femoral bone, a specimen obtained by swabbing the track surrounding the device, and blood were cultured. The rates of device colonization, osteomyelitis, and device-related osteomyelitis were compared between the two groups of rabbits. The antimicrobial-coated devices had a significantly lower rate of colonization than the uncoated devices (five of thirteen compared with twelve of twelve, p = 0.0016) and were associated with significantly lower rates of osteomyelitis (six of thirteen compared with twelve of twelve, p = 0.005) and device-related osteomyelitis (five of thirteen compared with twelve of twelve, p = 0.0016). Bacteremia did not develop in any rabbit. Orthopaedic devices coated with minocycline and rifampin significantly protected against device colonization and infection due to Staphylococcus aureus in this in vivo rabbit model. It is possible that orthopaedic devices coated with this unique combination of antimicrobial agents may protect against the development of clinical infection in humans.

Evaluation of rapid diagnostic tests in the detection of microbial invasion of the amniotic cavity

Abstract OBJECTIVE: We sought to determine and compare the value of several rapid diagnostic tests in the detection of intraamniotic infection. STUDY DESIGN: Gram stain, intraamniotic glucose level determination, leukocyte esterase assay, and the Limulus amebocyte lysate assay were performed on 144 amniotic fluid specimens retrieved by transabdominal amniocentesis in 136 patients with preterm premature rupture of the membranes or preterm labor. Diagnostic indices for a positive amniotic fluid culture and the development of clinical infection were calculated for each rapid test. Receiver-operator characteristic curves were generated to help select the optimal glucose level and combination of tests to detect intraamniotic infection. RESULTS: The greatest sensitivity for predicting either a positive culture or subsequent clinical infection in preterm labor patients and in predicting clinical infection in patients with preterm premature rupture of the membranes was demonstrated by a low glucose level. The Gram stain provided the greatest positive predictive value in patients with preterm labor. Combining the Gram stain and measurement of intraamniotic glucose levels did not improve sensitivity above glucose alone or positive predictive value above Gram stain alone. CONCLUSION: Leukocyte esterase determination and Limulus amebocyte lysate assay are insensitive indicators of intraamniotic infection. Selection of Gram stain or glucose level measurement alone or in combination as an appropriate screen for intraamniotic infection will depend on the clinicians' false-positive rate threshold.

Evaluation of rapid diagnostic tests in the detection of microbial invasion of the amniotic cavity

OBJECTIVE: We sought to determine and compare the value of several rapid diagnostic tests in the detection of intraamniotic infection. STUDY DESIGN: Gram stain, intraamniotic glucose level determination, leukocyte esterase assay, and the Limulus amebocyte lysate assay were performed on 144 amniotic fluid specimens retrieved by transabdominal amniocentesis in 136 patients with preterm premature rupture of the membranes or preterm labor. Diagnostic indices for a positive amniotic fluid culture and the development of clinical infection were calculated for each rapid test. Receiver-operator characteristic curves were generated to help select the optimal glucose level and combination of tests to detect intraamniotic infection. RESULTS: The greatest sensitivity for predicting either a positive culture or subsequent clinical infection in preterm labor patients and in predicting clinical infection in patients with preterm premature rupture of the membranes was demonstrated by a low glucose level. The Gram stain provided the greatest positive predictive value in patients with preterm labor. Combining the Gram stain and measurement of intraamniotic glucose levels did not improve sensitivity above glucose alone or positive predictive value above Gram stain alone. CONCLUSION: Leukocyte esterase determination and Limulus amebocyte lysate assay are insensitive indicators of intraamniotic infection. Selection of Gram stain or glucose level measurement alone or in combination as an appropriate screen for intraamniotic infection will depend on the clinicians' false-positive rate threshold.

A study of group A hemolytic Streptococcus carriers among school children. II. Significance of the findings.

SummaryIn the course of a study pursued for 2 consecutive years in normal children of a suburban public school of the Paris area, the following findings were noted: (1) when the technique used was sufficiently sensitive, the rate of healthy carriers was relatively high: 16.7% on an average, with a range of 6.7% to 30%. (2) this percentage seemed to present variations during the course of the year which are perhaps due to a seasonal factor. (3) the cumulative percentage was such that at the end of two years more than one subject in two was found, to have been a carrier of hemolytic streptococci at least once. (4) there was no correlation between the rate of carriers and the development of clinical infections (septic sore throat, scarlet fever). (5) the subjects fell into 4 groups: refractory subjects, occasional carriers, prolonged carriers of the same strain, prolonged carriers of different strains. (6) a “prolonged carrier”) factor was found to exist statistically, i.e. certain subjects were particularly receptive to the Group A hemolytic streptococcus, or conversely, certain subjects were refractory. (7) within the scope of our study this factor was found together with various other independent correlations. Of these, the correlations with the presence of tonsils and with bad conditions of hygiene (absence of running water in the child's home) were hardly surprising; that with a genetic factor (dark iris) was more unexpected, but has been established on equally as sound a basis.

Thyroid function in mothers of mongoloid infants.

SummaryIn the course of a study pursued for 2 consecutive years in normal children of a suburban public school of the Paris area, the following findings were noted: (1) when the technique used was sufficiently sensitive, the rate of healthy carriers was relatively high: 16.7%on an average, with a range of 6.7%to 30%. (2) this percentage seemed to present variations during the course of the year which are perhaps due to a seasonal factor. (3) the cumulative percentage was such that at the end of two years more than one subject in two was found, to have been a carrier of hemolytic streptococci a t least once. (4) there was no correlation between the rate of carriers and the development of clinical infections (septic sore throat, scarlet fever). (5) the subjects fell into 4 groups: refractory subjects, occasional carriers, prolonged carriers of the same strain, prolonged carriers of different strains. (6) a “prolonged carrier”) factor was found to exist statistically, i.e. certain subjects were particularly receptive to the Group A hemolytic streptococcus, or conversely, certain subjects were refractory. (7) within the scope of our study this factor was found together with various to, her independent correlations. Of these, the correlations with the presence of tonsils and with bad conditions of hygiene (absence of running water in the child's home) were hardly surprising; that with a genetic factor (dark iris) was more unexpected, but has been established on equally as sound a basis.