ABOUT GUIDANCE UTI TESTING METHODOLOGY
Methodology and Clinical Significance:
Guidance® UTI utilizes Multiplex PCR for the targeted molecular detection of bacterial DNA and antibiotic resistance genes. Additionally, antibiotic susceptibility is performed using a patented technique referred to as Pooled Antibiotic Susceptibility Testing (P-AST). Together, the results deliver personalized treatment options for urinary tract infections.
If detected, targets are reported semi-quantitatively as cells per milliliter in the following ranges:
– <10,000 cells/mL
– 10,000-49,999 cells/mL
– 50,000-99,999 cells/mL
– >100,000 cells/mL
– Coagulase Negative Staphylococcus: Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus lugdunenesis, and Staphylococcus saprophyticus
– Viridans Group Strep: Streptococcus anginosus, Streptococcus oralis, and Streptococcus pasteuranus
– Enterobacter Group: Klebsiella aerogenes (formally known as Enterobacter aerogenes), Enterobacter cloacae
Guidance® UTI also includes the detection of resistance genes. When detected, Resistance Genes Detected (RGD) will be indicated on the table of the report.
– Broad Spectrum resistant genes confer resistance across multiple classes of antibiotics including penicillin derivatives, cephalosporins, monobactams, and carbapenems.
– Extended-spectrum beta-lactamases (ESBL) are enzymes that are responsible for resistance to most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam. Infections with ESBL producing organisms have been associated with poor outcomes.
Pooled Antibiotic Sensitivity Testing:
Pooled Antibiotic Sensitivity Testing (P-AST) of the microbial community is determined via high-throughput, broth microdilution, spectrophotometric assay in which the population is applied to a panel of antibiotic agent’s array on a microplate to determine the Minimum Inhibitory Concentration (MIC).
P-AST is not performed for Virdians streptococci, or fastidious microorganisms such as Ureaplasma urealyticum, Actinobaculum schaalii, Aerococcus urinae, Alloscardovia omnicolens, Corynebacterium riegelii, Mycoplasma hominis, and Enterococcus faecium.
In addition to providing both the presence of resistance genes (R) and pooled antibiotic susceptibility patterns (S), we also include a table of antibiotics that have shown strong supportive evidence for use in the treatment of UTI.
The checkmarks indicate antibiotics listed in the table are based on the most current recommendations of treatment and should act as a guide for suspected UTI management. Appropriate medical judgement should be exercised by the health care provider before prescribing a course of treatment. Further treatment or workup may be necessary if clinically indicated.
White boxes with checkmarks indicate situations where the pool of organisms was susceptible to an antibiotic and there is supportive evidence for the organisms listed. There may be changes in research showing changes in antibiotic susceptibility. Although we attempt to update the report with new data promptly, we cannot prevent delays.
Candida auris is an emerging fungus that presents a serious global health threat and can be the cause of bloodstream infections, wound infections, and ear infections. It also has been isolated from respiratory and urine specimens. Click here for guidance on C. Auris.
We do not perform antifungal susceptibility testing.
We do not perform antiviral susceptibility testing.
The detection of BKPyV or JCPyV in the urine indicates infection, but detection of viruria is not sufficient to diagnose PyV-associated diseases.1
The detection of CMV from other sites other than blood indicates the presence of the virus but does not confirm active CMV disease. CMV may be shed in the urine intermittently for several months after acute CMV infection, even in otherwise healthy individuals.2 Immunosuppressed patients often shed virus in the urine and other specimen types (bronchoalveolar lavage fluid, stool) for prolonged periods of time in the absence of clinical disease.3 Viruria is not considered sufficient to make a diagnosis of CMV infection.4,5
Please refer to DOI: 10.1007/s11918-007-006-7 for further information regarding viral causes of UTI
Treatment Options for Sexually Transmitted Infections:
Guidance® UTI also tests for the presence of organisms known to cause sexually transmitted infections. Please follow the links below:
This test was developed, and its performance characteristics determined by Pathnostics. It has not been cleared or approved by the US Food and Drug Administration. The FDA has determined that such clearance or approvals is not necessary. This test is used for clinical purposes. It should not be regarded as investigational or for research. This laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88) as qualified to perform high complexity clinical testing. Urine specimens received greater than 5 days post collection may give unreliable cells/mL counts due to overgrowth of microorganism(s).
1. Egli A, Infanti L, Dumoulin A, Buser A, Samaridis J, Stebler C, Gosert R, Hirsch HH. Prevalence of polyomavirus BK and JC infection and replication in 400 healthy blood donors. J Infect Dis. 2009 Mar 15;199(6):837-46. doi: 10.1086/597126. PMID: 19434930.
2. Kotton CN, Kumar D, Caliendo AM, et al. Updated international consensus guidelines on the management of cytomegalovirus in solid-organ transplantation. Transplantation 2013; 96:333.
3. Razonable RR, Hayden RT. Clinical utility of viral load in management of cytomegalovirus infection after solid organ transplantation. Clin Microbiol Rev 2013; 26:703.
4. Ljungman P, Griffiths P. Definitions of cytomegalovirus infection and disease. In: Plotkins S, Michelson S (eds). Multidisciplinary Approach to Understanding Cytomegalovirus Disease. Amsterdam: Excerpta Medica Congress Series. Elsevier Science Publishers: Paris, 1993, pp 233–237.
5. 20 Ljungman P, Plotkins SA. Workship on CMV disease; definitions, clinical severity scores, and new syndromes. Scand J Infect Dis Suppl 1995; 99: 87–89.
LICENSES AND ACCREDITATIONS
CLIA (Clinical Laboratory Improvement Amendments of 1988): 05D2024468
State of California Department of Public Health: CLF00340926
Florida Agency for Health Care Administration: