Laboratory Diagnosis of \u3cem\u3eClostridium difficile \u3c/em\u3eInfection: Can Molecular Amplification Methods Move Us Out of Uncertainty?

The laboratory diagnosis of Clostridium difficile infection (CDI) continues to be challenging. Recent guidelines from professional societies in the United States note that enzyme immunoassays for toxins A and B do not have adequate sensitivity to be used alone for detecting CDI, yet the optimal method for diagnosing this infection remains unclear. Nucleic acid amplification tests (NAATs) that target chromosomal toxin genes (usually the toxin B gene, tcdB) show high sensitivity and specificity, provide rapid results, and are amenable to both batch and on-demand testing, but these tests were not universally recommended for routine use in the recent guidelines. Rather, two-step algorithms that use glutamate dehydrogenase (GDH) assays to screen for C. difficile in stool specimens, followed by either direct cytotoxin testing or culture to identify toxin-producing C. difficile isolates, were recommended in one guideline and either GDH algorithms or NAATs were recommended in another guideline. Unfortunately, neither culture nor direct cytotoxin testing is widely available. In addition, this two-step approach requires 48 to 92 hours to complete, which may delay the initiation of therapy and critical infection control measures. Recent studies also show the sensitivity of several GDH assays to be \u3c90%. This review considers the role of NAATs for diagnosing CDI and explores their potential advantages over two-step algorithms, including shorter time to results, while providing comparable, if not superior, accuracy

Bordetella Holmesii-Like Organisms Associated with Septicemia, Endocarditis, and Respiratory Failure

We recovered an unusual bacterial strain from blood or sputum of three patients with septicemia, endocarditis, and/or respiratory failure. The three isolates were thin, curved, gram-negative, light brown, pigment-producing bacilli with variable catalase activity. They were asaccharolytic, oxidasenegative, nonmotile, and fastidious. Identification was not possible on the basis of these characteristics alone or in combination with cellular fatty acid profiles. Nucleic acid amplification and sequence analysis of the 16S rRNA gene revealed that all three isolates were identical and most closely related to the emerging pathogen Bordetella holmesii, diverging from the published sequence at three nucleotide positions (99.8% similarity). Isolation of a B. holmesii-like pathogen from sputum suggests that, in addition to producing septicemia, the organism may inhabit the respiratory tract like other Bordetella species

Prospective study of the feasibility of point-of-care testing strategy for carbapenem-resistant organism detection

Background/aims: In an investigator-initiated, prospective study, we evaluated the feasibility of a five-gene sequence point-of-care (POC) testing strategy (Xpert CARBA-R Assay, Cepheid Inc., Sunnyvale, CA, USA), compared to reference laboratory PCR (48 – 72 hours turnaround time, two gene sequences), in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and in a hospital outbreak investigation. Methods: After informed consent, patients undergoing ERCP (September 2015 – April 2016, n = 191) at Mayo Clinic and potential hospital contacts (n = 9) of an index carbapenem-resistant organism (CRO)-positive inpatient were included. Two rectal swabs, one each for reference and POC assays were obtained. The Xpert CARBA-R Assay enables qualitative rapid detection of five beta-lactamase gene sequences associated with carbapenem-non-susceptibility in Gram-negative bacteria. Feasibility parameters (specimen processing and assay run time, ease of use) and percent agreement between the tests were calculated using JMP Pro11 (SAS Corp, Cary, NC, USA). Results: Mean age was 62 ± 15 years; 108 (54 %) were male. Both tests were successfully performed in all patients. The POC test was rated by endoscopy nurses as easy/very easy to conduct in 193 patients (97 %); median assay run time and median time for specimen collection and processing were 55 minutes (interquartile range IQR: 53 – 55 minutes) and 3 minutes (IQR: 3 – 6 minutes), respectively. In 200/201 (99.5 %) tests, there was agreement between the POC and reference PCR. Conclusions: The more comprehensive POC CRO testing of patients in the endoscopy suite is feasible and results are available in \u3c 1 hour. This strategy may enable rapid risk stratification of duodenoscope exposure to CRO and potentially improve operational efficiency and decrease costs

mRNA Detection in Anal Cytology: A Feasible Approach for Anal Cancer Screening in Men Who Have Sex with Men Living With HIV

There is growing interest in anal cancer screening strategies. However, cytological/molecular evaluation of anal samples is challenging. We aimed to determine the feasibility of detecting, in anal liquid-based cytologies, the expression of biomarkers involved in the cell cycle disturbance elicited by human papillomavirus (HPV). The accuracy of this approach in the identification of high-grade squamous intraepithelial lesions/anal intraepithelial neoplasia grade2-3 (HSIL/AIN2-3) was also evaluated. 215 anal cytologies from men having sex with men living with human immunodeficiency virus were evaluated. Patients showing concordant cytological and anoscopy-directed biopsy diagnosis were selected: 70 with negative cytology and HPV test, 70 with low-grade SIL (LSIL/AIN1) cytology and biopsy, and 75 with cytology and biopsy of HSIL/AIN2-3. CDKN2A/p16, MKI67 and TOP2A mRNA expression was analyzed. HPV detection was performed with Xpert HPV Assay (Cepheid, Sunnyvale, CA, USA). HSIL/AIN2-3 showed higher expression for the biomarkers than LSIL/AIN1 or negative samples. The specificity for HSIL/AIN2-3 detection for a sensitivity established at 70% was 44.7% (95%confidence interval [CI] 36.5-53.2) for TOP2A and MKI67 and 54.5% (95%CI 46.0-62.8%) for CDKN2A/p16. mRNA detection of cell biomarkers in anal liquid-based cytology is feasible. Further studies are warranted to confirm if strategies based on mRNA detection have any role in anal cancer screening

Babesia divergens–like Infection, Washington State

Most reported U.S. zoonotic cases of babesiosis have occurred in the Northeast and been caused by Babesia microti. In Washington State, three cases of babesiosis have been reported previously, which were caused by WA1 (for “Washington 1”)-type parasites. We investigated a case of babesiosis in Washington in an 82–year-old man whose spleen had been removed and whose parasitemia level was 41.4%. The complete 18S ribosomal RNA gene of the parasite was amplified from specimens of his whole blood by polymerase chain reaction. Phylogenetic analysis showed the parasite is most closely related, but not identical, to B. divergens (similarity score, 99.5%), a bovine parasite in Europe. By indirect fluorescent-antibody testing, his serum reacted to B. divergens but not to B. microti or WA1 antigens. This case demonstrates that babesiosis can be caused by novel parasites detectable by manual examination of blood smears but not by serologic or molecular testing for B. microti or WA1-type parasites

Symptomatic asymmetry in the first six months of life: differential diagnosis

Asymmetry in infancy is a clinical condition with a wide variation in appearances (shape, posture, and movement), etiology, localization, and severity. The prevalence of an asymmetric positional preference is 12% of all newborns during the first six months of life. The asymmetry is either idiopathic or symptomatic. Pediatricians and physiotherapists have to distinguish symptomatic asymmetry (SA) from idiopathic asymmetry (IA) when examining young infants with a positional preference to determine the prognosis and the intervention strategy. The majority of cases will be idiopathic, but the initial presentation of a positional preference might be a symptom of a more serious underlying disorder. The purpose of this review is to synthesize the current information on the incidence of SA, as well as the possible causes and the accompanying signs that differentiate SA from IA. This review presents an overview of the nine most prevalent disorders in infants in their first six months of life leading to SA. We have discovered that the literature does not provide a comprehensive analysis of the incidence, characteristics, signs, and symptoms of SA. Knowledge of the presented clues is important in the clinical decision making with regard to young infants with asymmetry. We recommend to design a valid and useful screening instrument

Metopic synostosis

Premature closure of the metopic suture results in a growth restriction of the frontal bones, which leads to a skull malformation known as trigonocephaly. Over the course of recent decades, its incidence has been rising, currently making it the second most common type of craniosynostosis. Treatment consists of a cranioplasty, usually preformed before the age of 1 year. Metopic synostosis is linked with an increased level of neurodevelopmental delays. Theories on the etiology of these delays range from a reduced volume of the anterior cranial fossa to intrinsic malformations of the brain. This paper aims to provide an overview of this entity by giving an update on the epidemiology, etiology, evolution of treatment, follow-up, and neurodevelopment of metopic synostosis