|
Investigation: (b)(6) reported a discrepant (b)(6) result on the filmarray bcid panel after testing a blood sample from a (b)(6) year old, male patient.The patient did not have a prior (b)(6) infection.The patient was on ciprofloxacin and rifaximin for spontaneous bacterial peritonitis (sbp) prophylaxis and hepatic encephalopathy, respectively, at the time of the blood draw.Two sets of blood culture bottles were collected on (b)(6) 2019, and one set flagged (b)(6).On (b)(6) 2019, a (b)(6) blood culture (bactalert sn anaerobic bottle, lot# 1052516, exp.November 20, 2019) was tested on the filmarray bcid panel and the result was (b)(6).The customer used id by staph latex, and the customer stated culture results did not show signs of a mixed culture.Four isolates were also tested this same day for susceptibility by microscan (which shows (b)(6) sensitivity) and the preliminary result was (b)(6).On (b)(6) 2019, the patient was put on (b)(6).The customer reported that the (b)(6) treatment was partly due to the filmarray bcid result, and partly due to a possible beta-lactam allergy.After one dose of (b)(6), the patient developed tongue swelling and was switched to (b)(6).On (b)(6) 2019, the same blood culture was repeated on the filmarray bcid panel and the result was (b)(6).The patient developed acute kidney injury (scr 1.21 mg/dl) on (b)(6) 2019, which according to the customer was "likely multifactorial" as the patient had hypovolemia, hepatorenal syndrome, and was on nephrotoxic medications (contrast on (b)(6) 2019, and (b)(6) on (b)(6) 2019).The patient's serum creatinine continued to increase the following three days (1.40, 1.69, 1.81 mg/dl respectively) and was reported as 1.62 mg/dl when the patient was admitted to hospice on (b)(6) 2019.Antibiotic treatment was discontinued when the patient was admitted to hospice care and the patient passed away on (b)(6) 2019.The customer reported that they followed decontamination protocol.Please note: there is a reasonable risk that (b)(6) may have contributed to increase kidney dysfunction.However, medications prior to the introduction of (b)(6) (ciprofloxacin, rifaxamin and contrast dye) can all contribute to renal insufficiency.Co-administration of (b)(6) with other nephrotoxic agents (in this case (b)(6)) has been associated with greater severity of aki and a lower probability of renal recovery.Incomplete renal recovery accelerates the progression of chronic kidney disease (ckd), and may result in higher rates of cardiovascular morbidity and fatality.At the time of (b)(6) administration, the serum creatinine levels were at the high end of the normal range (review of vancomycin-induced renal toxicity: an update.Ther adv endocrinol metab 2016 jun; 7(3): 136-147).The patient had other serious comorbidities that most likely contributed to the mortality including hypovolemia and hepatorenal syndrome which contributed to a high risk for sbp (hence ciprofloxacin prophylaxis), and hepatic encephalopathy (rifaxamin).However based on the information submitted it cannot be determined if the (b)(6) was responsible for the aki or increased the severity of the aki since the patient was initially on two drugs and then was co-administered with a drug that all could have resulted in or increased the risk for and the severity of kidney injury.Quality control (qc) records for pouch lot# 455919 (kit lot# 0116219) were reviewed.This pouch lost passed the qc criteria and was found within specifications.No run malfunction was observed and the filmarray instrument (serial# (b)(4)) was working within design specifications.Conclusion: the investigation concluded that the most likely cause for the discrepant result was a heterogeneous mixture of (b)(6) resistance as well as sensitivity/specificity differences between the filmarray bcid panel, standard culture, and traditional ast methods.The filmarray bcid panel does not specifically attribute meca-mediated methicillin resistance to either s.Aureus or other staphylococcus species.Unlike ast methods, filmarray bcid reports detections from the blood culture population as a whole and not from a single/few isolated colonies.The multi-species assays detect the most prevalent coagulase-negative staphylococcus (cons) species encountered in blood culture specimens and can also react with high levels of s.Aureus.No (b)(6) species were observed in culture which may indicate a mixed population of (b)(6).However, this is a large and diverse group and detection by filmarray bcid panel assays is variable (filmarray bcid panel instruction booklet, table 7, "multiple assay interpretations" section, https://www.Online-ifu.Com/iti0045).It is also possible that the (b)(6) contained (b)(6) but this mechanism was not expressed or inactivated.It is estimated that a small percentage (approximately 3% but likely higher) of s.Aureus strains that are positive for meca via pcr are highly susceptible to methicillin-like antibiotics as reported by ast methods [1-4].In addition, accurate identification of mrsa from mssa is further complicated by phenotypic variability in methicillin susceptibility, also known as heteroresistance [4-5].Other studies also report cases of s.Aureus strains reverting from methicillin susceptible to methicillin resistant during antibiotic treatment [4-5].Detection of bcid targets does not imply that the corresponding organisms are infectious or the causative agents for clinical symptoms.Results from the bcid panel must be correlated with the clinical history, epidemiological data, and other data available to the clinician evaluating the patient.Late signatures of staphlyococcus1 and staphylococcus2 suggest the meca detection could be attributed to a cons species, which potentially could be a skin flora contaminant.During panel development, meca (staphylococcus detected, s.Aureus detected) showed robust performance comparing to phenotypic antimicrobial susceptibility testing (ast) methods, with a sensitivity of 97.7% (95% ci 93.4 - 99.5%) and specificity of 96.7% (95% ci 91.7 - 99.1%) for prospective staphylococcus, s.Aureus detected (filmarray bcid panel instruction booklet, table 26, https://www.Online-ifu.Com/iti0045).References: hososaka y, hanaki h, endo h et al.2007.Characterization of oxacillin-susceptible meca-positive staphylococcus aureus: a new type of mrsa.J infect chemother; 13:79-86.Kumar va, steffy k, chatterjee m et al.2013.Detection of oxacillin-susceptible meca-positive staphylococcus aureus isolates by use of chromogenic medium mrsa id.J clin microbiol.51:318-9.Salem-bekhit mm.2014.Phenotypic and genotypic characterization of nosocomial isolates of staphylococcus aureus with reference to methicillin resistance.Trop j pharm res; 13:1239-46.Proulx mk, et al.2015.Reversion from methicillin susceptibility to methicillin resistance in staphylococcus aureus during treatment of bacteremia.J infect dis.213(6):1041-48.Sakoulas g, et al.2001.Methicillin-resistant staphylococcus aureus: comparison of susceptibility testing methods and analysis of meca-positive susceptible strains.J clin microbiol.39(1):3946-51.
|
|
(b)(6) reported a discrepant (b)(6) result on the filmarray blood culture identification (bcid) panel after testing a blood sample from a (b)(6) year old, male patient.Due to the filmarray bcid panel result, the customer reported that treatment was altered and there was potential harm to the patient.Ultimately, the patient developed acute kidney injury (aki) and expired on (b)(6) 2019.Upon investigation, no malfunction occurred and the system was working within specification.The investigation concluded that the most likely cause for this discrepant result was sensitivity/specificity differences between the filmarray bcid panel, standard culture, and ast methods.
|
