Treatment and Epidemiology of Third-Generation Cephalosporin-Resistant Urinary Tract Infections.

BACKGROUND AND OBJECTIVES: Limited data are available on the contemporary epidemiology, clinical management, and health care utilization for pediatric urinary tract infection (UTI) due to third-generation cephalosporin-resistant Enterobacterales (G3CR) in the United States. The objective is to describe the epidemiology, antimicrobial treatment and response, and health care utilization associated with G3CR UTI. METHODS: Multisite, matched cohort-control study including children with G3CR UTI versus non-G3CR UTI. UTI was defined as per American Academy of Pediatrics guidelines, and G3CR as resistance to ceftriaxone, cefotaxime, or ceftazidime. We collected data from the acute phase of illness to 6 months thereafter. RESULTS: Among 107 children with G3CR UTI and 206 non-G3CR UTI with documented assessment of response, the proportion with significant improvement on initial therapy was similar (52% vs 57%; odds ratio [OR], 0.81; 95% confidence interval [CI], 0.44-1.50). Patients with G3CR were more frequently hospitalized at presentation (38% vs 17%; OR, 3.03; 95% CI, 1.77-5.19). In the follow-up period, more patients with G3CR had urine cultures (75% vs 53%; OR, 2.61; 95% CI, 1.33-5.24), antimicrobial treatment of any indication (53% vs 29%; OR, 2.82; 95% CI, 1.47-5.39), and subspecialty consultation (23% vs 6%; OR, 4.52; 95% CI, 2.10-10.09). In multivariate analysis, previous systemic antimicrobial therapy remained a significant risk factor for G3CR UTI (adjusted OR, 1.91; 95% CI, 1.06-3.44). CONCLUSIONS: We did not observe a significant difference in response to therapy between G3CR and susceptible UTI, but subsequent health care utilization was significantly increased.

Revisiting approaches to and considerations for urinalysis and urine culture reflexive testing.

Urinalysis is considered the world's oldest laboratory test. Today, many laboratories use macroscopic urinalysis as a screening tool to determine when to subject urine samples for a microscopic urinalysis and/or bacterial culture. While reflexive urine microscopy has been practiced for decades, and reflexive urine culture, more recently, evidence-based guidelines regarding optimal reflexive criteria and workflows are lacking. Standard approaches are hindered, in part, by a lack of harmonization of urinalysis and urine culture practices, heterogeneity in patient populations that are studied, and lack of provider adherence to recommended practices. This review summarizes studies that have evaluated the performance of reflexive urine microscopy and reflexive urine culture, particularly in the context of urinary tract infections. It also examines reported clinical outcomes from reflexive urinalysis interventions and their impact on antibiotic stewardship efforts. Finally, it discusses laboratory operational considerations for the implementation of reflexive algorithms.

Correlation of Chemical Urinalysis to Microscopic Urinalysis and Urine Culture: Implications for Reflex Urinalysis Workflows.

BACKGROUND: Urinalysis (UA) reflex testing approaches, which offer potential for savings in labor and result turnaround time, may rely on the performance of a chemical UA screen to determine which urine samples need microscopic UA and/or urine culture. We correlated chemical UA, microscopic UA, and urine culture results to determine the performance of chemical UA as a screening tool for reflex testing approaches. METHODS: Consecutive UA results for 9127 tests (simultaneous chemical UA and microscopic UA) were retrospectively reviewed and correlated. Urine culture results were also correlated for 3127 samples that had urine culture ordered within 24 h of UA. Positivity criteria for each UA method were predefined. RESULTS: Chemical UA yielded the following performance specifications for predicting microscopic findings: 93.0% sensitivity, 56.9% specificity, 64.7% positive predictive value, 90.5% negative predictive value. 3.2% of samples were negative by chemical UA but positive by microscopic UA. Of the samples with urine culture results available, 6.3% were negative by chemical UA but had clinically-significant positive urine cultures. CONCLUSIONS: Reflex testing of microscopic UA and/or urine culture dependent from chemical UA results provides a feasible opportunity to reduce unnecessary testing.

Automated Detection of Streptococcus pyogenes Pharyngitis by Use of Colorex Strep A CHROMagar and WASPLab Artificial Intelligence Chromogenic Detection Module Software.

Colorex Strep A agar (CHROMagar, Paris, France) was evaluated with PhenoMATRIX chromogenic detection module (CDM) software (Copan Diagnostics Inc., Murrieta, CA) to detect group A Streptococcus (GAS) from throat specimens. The software results were compared to those of manual plate image reading. In addition, GAS PCR testing was performed on all specimens. True-positive specimens were defined as culture-positive (by either PhenoMATRIX CDM or manual reading) specimens confirmed as GAS by matrix-assisted laser desorption ionization-time of flight mass spectrometry plus any culture-negative specimens that were positive by both initial and repeat PCR testing. Of 480 specimens, 96 were considered true-positive specimens. Software reading of the chromogenic agar for suspected colonies detected 110 orange colonies, whereas technologist reading interpreted only 93/110 specimens (84.5%) as positive. None of the 361 cultures interpreted as negative by the PhenoMATRIX CDM software was positive by manual reading. In comparison with true-positive results, the sensitivity and specificity were 96.9% and 100% for PCR testing, 87.5% and 97.7% for technologist reading of chromogenic agar, 90.6% and 94.0% for software reading of chromogenic agar, 83.3% and 97.7% for technologist reading for ß-hemolysis on blood agar, and 39.5% and 83.1% for technologist reading for ß-hemolysis on blood agar accompanied by any zone of inhibition around a bacitracin-impregnated disk, respectively. The software had the most accurate results of the non-molecular testing methods, detecting all suspected colonies on the chromogenic agar and identifying 3 additional true-positive specimens that were missed by manual reading. The PhenoMATRIX CDM software and the Colorex Strep A agar can improve detection of GAS from throat specimens, and they compared favorably to molecular testing.

Don't Get Wound Up: Revised Fluoroquinolone Breakpoints for Enterobacteriaceae and Pseudomonas aeruginosa.

Fluoroquinolones remain some of the more commonly prescribed antimicrobial agents in the United States, despite the wide array of reported side effects that are associated with their use. In 2019, the Clinical and Laboratory Standards Institute revised the fluoroquinolone antimicrobial susceptibility testing breakpoints for both Enterobacteriaceae and Pseudomonas aeruginosa This breakpoint revision was deemed necessary on the basis of pharmacokinetic and pharmacodynamic analyses suggesting that the previous breakpoints were too high, in addition to the inability of the previous breakpoints to detect low-level resistance to this antibiotic class. In this minireview, we review the published data in support of this revision, as well as the potential challenges that these breakpoint revisions are likely to pose for clinical laboratories.

Aspergillus endocarditis diagnosed by fungemia plus serum antigen testing.

Fungal endocarditis remains an uncommon clinical diagnosis, though is likely to become more frequent due to the global increase in transplantations and cardiac valvular surgery. A case of prosthetic valve endocarditis due to Aspergillus fumigatus is described that was diagnosed with serologic fungal markers and confirmed with positive blood cultures, an uncommon finding.

Invasive pulmonary mucormycosis and aspergillosis in a patient with decompensated hepatic cirrhosis.

Invasive pulmonary mucormycosis and aspergillosis are rare, life-threatening fungal infections. Most documented cases have been reported in non-cirrhotic patients with diabetes mellitus, neutropenia, or treatment with corticosteroids. The prevalence of each infection is low among patients with hepatic cirrhosis. We report the first likely case of combined invasive pulmonary mucormycosis and aspergillosis in a male with decompensated hepatic cirrhosis. This report also highlights the first non-diabetic case of invasive pulmonary mucormycosis with decompensated hepatic cirrhosis.

Molecular Testing for Detection of Groups A, C, and G ß-Hemolytic Streptococci in Pharyngeal Samples from Children.

BACKGROUND: Group A Streptococcus (GAS) and large colony-forming group C (GCS) and G (GGS) ß-hemolytic streptococci are important causes of acute pharyngitis in children and adults. Rapid and accurate diagnosis of streptococcal pharyngitis can improve patient care and potentially reduce transmission. In this study, we evaluated the performance of the Lyra Direct Strep (LDS) assay for detection of GAS and GCS/GGS compared with traditional culture methods. METHODS: Pharyngeal samples obtained from 278 children presenting to the emergency department with initial negative GAS rapid antigen detection test (RADT) were used. All samples were cultured as part of routine care and tested in batches using the LDS assay. RESULTS: Of 278 pharyngeal samples with negative GAS RADT, 37 (13.3%) and 63 (22.7%) patients were positive for GAS by culture and LDS assay, respectively. Four (1.4%) patients were positive for GCS or GGS by culture or LDS assay. The LDS assay demonstrated sensitivity and specificity of 97.6% and 89.0%, respectively, compared with culture as the gold standard. Repeat culture and an alternate PCR showed that 85.7% (24 of 28) of discrepant samples agreed with findings of the LDS assay. Since implementation, the LDS assay shows a positivity rate of 21.0% (281 of 1340) compared with 11.7% (246 of 2110) by culture in the previous year. CONCLUSIONS: We successfully implemented the LDS assay at our institution and have observed a significant increase in the positivity rate of GAS compared with culture. The LDS assay alone allowed for the elimination of ß-streptococci screening by culture at our institution.

Impact of a Rapid Herpes Simplex Virus PCR Assay on Duration of Acyclovir Therapy.

Herpes simplex virus (HSV) infections of the central nervous system (CNS) are associated with significant morbidity and mortality rates in children. This study assessed the impact of a direct HSV (dHSV) PCR assay on the time to result reporting and the duration of acyclovir therapy for children with signs and symptoms of meningitis and encephalitis. A total of 363 patients with HSV PCR results from cerebrospinal fluid (CSF) samples were included in this retrospective analysis, divided into preimplementation and postimplementation groups. For the preimplementation group, CSF testing was performed using a laboratory-developed real-time PCR assay; for the postimplementation group, CSF samples were tested using a direct sample-to-answer assay. All CSF samples were negative for HSV. Over 60% of patients from both groups were prescribed acyclovir. The average HSV PCR test turnaround time for the postimplementation group was reduced by 14.5 h (23.6 h versus 9.1 h; P < 0.001). Furthermore, 79 patients (43.6%) in the postimplementation group had dHSV PCR results reported <4 h after specimen collection. The mean time from specimen collection to acyclovir discontinuation was 17.1 h shorter in the postimplementation group (31.1 h versus 14 h; P < 0.001). The median duration of acyclovir therapy was also significantly reduced in the postimplementation group (29.2 h versus 14.3 h; P = 0.01). Our investigation suggests that implementation of rapid HSV PCR testing can decrease turnaround times and the duration of unnecessary acyclovir therapy.

Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.

Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing. All samples underwent "head to head" re-testing using both RCA and direct fluorescence assay (DFA). Community level results from three sites indicated that 54.4% (166/305) of Meridian ImmunoCard STAT! positives and 87.0% (67/77) of Remel Xpect positives were confirmed by DFA. When samples were retested by RCA at state laboratories and compared with DFA, 83.3% (155/186) of Meridian ImmunoCard STAT! positives and 95.2% (60/63) of Remel Xpect positives were confirmed. The percentage of confirmed community results varied by site: Minnesota, 39.0%; New York, 63.9%; and Wisconsin, 72.1%. The percentage of confirmed community results decreased with patient age; 12.5% of community positive tests could be confirmed by DFA for patients 60 years of age or older. The percentage of confirmed results did not differ significantly by sex, storage temperature, time between sample collection and testing, or season. Findings from this study demonstrate a lower confirmation rate of community RCA positives when compared to RCA positives identified at state laboratories. Elucidating the causes of decreased test performance in order to improve overall community laboratory performance of these tests is critical for understanding the epidemiology of cryptosporidiosis in the United States (US).

Prevalence of Fusobacterium necrophorum in Children Presenting with Pharyngitis.

Fusobacterium necrophorum, an obligate anaerobic bacterium, was recently reported to be an important cause of bacterial pharyngitis with a prevalence as high as that of group A Streptococcus (GAS) in adolescents and young adults. Importantly, F. necrophorum is the primary causative agent of the life-threatening Lemierre's syndrome, and screening of pharyngeal samples may be warranted for its early detection and prevention. The aim of this study was to determine the prevalences of F. necrophorum and groups A and C/G streptococci as agents of bacterial pharyngitis in children. Pharyngeal samples (n = 300) were collected from pediatric patients presenting to the emergency department with signs and symptoms of pharyngitis. Overall, 10 (3.3%), 79 (26.3%), and 4 (1.3%) patients were PCR positive for F. necrophorum, GAS, and group C/G streptococci, respectively. The prevalence of F. necrophorum was significantly higher in patients between the ages of 14 and 20 years at 13.5% than in patients aged 14 years and younger (1.9%, P < 0.001). All positive patients presented with signs and symptoms similar to GAS pharyngitis. Our data demonstrated a potential role for F. necrophorum as a pathogen of pharyngitis among young adults, but suggests that the prevalence of F. necrophorum is low in preadolescent patients.

Surveillance of Wisconsin Antibacterial Susceptibility Patterns.

BACKGROUND: Antimicrobial resistance presents a threat to quality patient care. Knowledge of localantibacterial susceptibility patterns can guide clinicians in empiric antibacterial administration andassist pharmacists and infectious disease physicians in development of appropriate therapeutic pathways. METHODS: To characterize Wisconsin antibacterial susceptibility patterns and elucidate geographicor temporal variation in antibacterial resistance, a retrospective, observational analysis of antibiogram data was performed. Seventy-two members of the Wisconsin Clinical Laboratory Network(WCLN) submitted antibiograms describing clinically significant isolates tested in calendar year 2013 to the WCLN Laboratory Technical Advisory Group. RESULTS: In the context of commonly reported antibacterial agents, data were compiled for approximately 75,800 isolates of Escherichia coi; 13,300 Klebsiella pneumoniae; 6300 Proteus mirobilis;2800 Enterobacter cloacae; 8400 Pseudomonas aeruginosa; 30,000 S aureus; 11,200 coagulase-negative Staphylococcus spp; and 13,800 Enterococcus spp. P mirobilis isolates from northern Wisconsin were more likely to demonstrate resistance than those in the southern region. In contrast, P aeruginosa isolates from southern Wisconsin had decreased susceptibility to a number ofagents when compared to other regions. Temporal trending in decreased E coli and P mirabilis susceptibility to fluoroquinolones and trimethoprimsulfamethoxazole was observed. Increased methicillin-resistant Staphylococcus oureus (MRSA) rates were observed in northwest and southeastWisconsin. In general, northeast Wisconsin exhibited less frequency of antibacterial resistance. CONCLUSIONS: Geographic variation exists with respect to antibacterial resistance, particularly inareas of Wisconsin adjacent to large population centers of neighboring states. Antibacterial surveillance in Wisconsin is indicated on a regular basis to assess emerging trends in antibacterial resistance. Existing WCLN infrastructure allows for such investigations.

Human immunodeficiency virus testing pitfalls and clinical suspicion.

Universal human immunodeficiency virus (HIV) screening was recommended in 2012, and major improvements in HIV testing have occurred in the past decade, but identification of HIV infected individuals remains inadequate in the United States. We report the case of a seronegative HIV-infected man who despite clinical and laboratory findings of acquired immunodeficiency syndrome,repeatedly tested nonreactive to third-generation HIV enzyme immunoassays (EIAs) and Western blot testing. Serologic diagnosis in this case required fourth-generation EIA testing due to the seronegativity of standard testing. The fourth-generation HIV EIA was positive presumably because it detects p24 HIV antigen as well as antibodies, unlike rapid HIV tests and third-generation HIV EIAs.This case highlights not only the importance of frontline providers to understand the different testing methodologies for HIV screening and their limitations but the importance of clinical suspicion as well.

Pooling nasopharyngeal/throat swab specimens to increase testing capacity for influenza viruses by PCR.

Real-time PCR methodology can be applied to rapidly and accurately detect influenza viruses. During times of surge testing or enhanced pandemic surveillance, public health laboratories (PHLs) may experience overwhelming demand for testing, even while the prevalence of positive specimens remains low. To improve laboratory capacity and testing efficiency during surges, we evaluated whether nasopharyngeal (NP)/throat swab specimens can be pooled and tested for the presence of the 2009 H1N1 influenza virus without a reduction in sensitivity. Pools of 10 specimens were extracted and concentrated upon elution on the MagNA Pure LC instrument, and real-time PCR was performed on the Applied Biosystems 7500 Fast platform, using the CDC swine influenza virus real-time RT-PCR detection panel (rRT-PCR swine flu panel). Specimens in positive pools were singly re-extracted and retested by PCR to identify individual positive samples. Initial studies showed that spiking a pool of nine negative specimens (100 µl each) or 900 µl of virus transport medium with 100 µl of a positive clinical specimen caused no loss of sensitivity by rRT-PCR testing. Pools containing either multiple positive specimens or specimens positive for other respiratory viruses also showed no negative effect on crossing threshold (C(T)) values. To test the robustness of the pooling protocol, a panel of 50 blinded samples was sent to three PHLs and tested in five pools of 10. All PHLs correctly identified the positive specimens. This study demonstrates the feasibility of using a pooling strategy to increase capacity and conserve resources during surge testing and periods of enhanced influenza surveillance when the prevalence is low.

Informed consent and the cognitively impaired geriatric dental patient.

Many geriatric patients will have cognitive impairment, sometimes temporary and other times progressive. Dentists are challenged to evaluate for the presence of cognitive impairment that can affect the consent process. This review gives an overview of types of cognitive impairments, clues to recognizing these conditions, how they affect the dental consent process, and what makes an effective informed consent. When there is doubt of a patient's capacity to consent, prudence calls for stopping dental treatment and referring the patient for a medical evaluation.

Influenza antiviral resistance testing in new york and wisconsin, 2006 to 2008: methodology and surveillance data.

The need for effective influenza antiviral susceptibility surveillance methods has increased due to the emergence of near-universal adamantane resistance in influenza A/H3N2 viruses during the 2005-2006 season and the appearance of oseltamivir resistance in the influenza A/H1N1 virus subtype during the 2007-2008 season. The two classes of influenza antivirals, the neuraminidase inhibitors (NAIs) and the adamantanes, are well characterized, as are many mutations that can confer resistance to these drugs. Adamantane resistance is imparted mainly by a S31N mutation in the matrix gene, while NAI resistance can result from a number of mutations in the neuraminidase gene. During the 2007-2008 season, a neuraminidase mutation (H274Y) conferring resistance to the NAI oseltamivir emerged worldwide in the A/H1N1 virus subtype. Surveillance methodology and data from New York (NY) and Wisconsin (WI) for the 2006-2007 and 2007-2008 influenza seasons are presented. We used an existing pyrosequencing method (R. A. Bright et al., Lancet 366:1175-1181, 2005) and a modified version of this method for detection of adamantane resistance mutations. For NAI resistance mutation detection, we used a mutation-specific pyrosequencing technique and developed a neuraminidase gene dideoxy sequencing method. Adamantane resistance in the A/H3N2 virus samples was 100% for 2007-2008, similar to the 99.8% resistance nationwide as reported by the CDC. Adamantane resistance was found in only 1.2% of NY and WI A/H1N1 virus samples, compared to that found in 10.8% of samples tested nationwide as reported by the CDC. Influenza A/H1N1 virus H274Y mutants were found in 11.1% of NY samples for 2007-2008, a level comparable to the 10.9% nationwide level reported by the CDC; in contrast, mutants were found in 17.4% of WI samples. These results indicate the need for regional influenza antiviral surveillance.