Persistent diarrhea (PD; duration >/=14 days) is a growing part of the global burden of diarrheal diseases. A 45-month prospective cohort study (with illness, nutritional, and microbiologic surveillance) was conducted in a shantytown in northeastern Brazil, to elucidate the epidemiology, nutritional impact, and causes of PD in early childhood (0-3 years of age). A nested case-control design was used to examine children's diarrhea burden and nutritional status before and after a first PD illness. PD illnesses accounted for 8% of episodes and 34% of days of diarrhea. First PD illnesses were preceded by a doubling of acute diarrhea burdens, were followed by further 2.6-3.5-fold increased diarrhea burdens for 18 months, and were associated with acute weight shortfalls. Exclusively breast-fed children had 8-fold lower diarrhea rates than did weaned children. PD-associated etiologic agents included Cryptosporidium, Giardia, enteric adenoviruses, and enterotoxigenic Escherichia coli. PD signals growth shortfalls and increased diarrhea burdens; children with PD merit extended support, and the illness warrants further study to elucidate its prevention, treatment, and impact.
A strain of Streptococcus pyogenes resistant to multiple fluoroquinolones was isolated from the blood of an immunocompromised patient. Resistance to fluoroquinolones in S. pyogenes has not been previously studied. Compared to 10 sensitive strains of S. pyogenes, the fluoroquinolone-resistant clinical isolate of S. pyogenes presented point mutations in gyrA, predicting that serine-81 was changed to phenylalanine and that methionine-99 was changed to leucine, and in parC, predicting that serine-79 was changed to tyrosine. The mechanism of fluoroquinolone resistance in this isolate of S. pyogenes appears to be analogous to previously reported mechanisms for Streptococcus pneumoniae.
We evaluated the use of 7SL RNA gene sequences for the identification of Leishmania spp. A fragment (approximately 137 basepairs) of the 7SL RNA gene from 13 reference strains and 18 clinical isolates of 11 different Leishmania species was amplified and sequenced using conserved primers. Reference strains from each Leishmania spp. complex showed unique sequences. The nucleotide sequences were compared pairwise and a range of 81.0-99.3% intercomplex similarity was observed. Clinical isolates of the same species had sequences identical to the corresponding reference strains; thus, the intraspecies similarity was 100%. A phylogenetic tree derived from the 7SL RNA gene partial sequences was constructed and is in agreement with accepted phylogenetic schemes.
SUMMARY Objectives To investigate the utility of beta-D-glucan (BDG) testing in bronchoalveolar lavage (BAL) fluid for the diagnosis of invasive fungal infection (IFI), as compared to BAL galactomannan (GM). Methods We retrospectively reviewed medical records of 132 consecutive patients at the National Institutes of Health (NIH) in whom BAL BDG testing was performed for diagnosis of pneumonia. Using the European Organization for Research and Treatment of Cancer/Mycoses Study Group guidelines, we determined which patients had proven or probable IFI, and assessed the diagnostic performance of BAL BDG testing, relative to BAL GM. We also determined the reproducibility of the BDG assay in BAL via repeat testing of patient samples. Results Ten patients had Pneumocystis pneumonia, and 34 patients had proven/probable IFI, including 14 with invasive aspergillosis (IA). BAL BDG was 100% sensitive for Pneumocystis. Although BAL BDG had similar sensitivity to BAL GM for the diagnosis of IA and IFI, it exhibited inferior specificity. Repeat testing demonstrated poor reproducibility of the BDG assay in BAL but not in serum. Conclusions BDG testing exhibits poor specificity and reproducibility in BAL. Identification of the BAL-specific factors that may interfere with the performance of the assay could improve the clinical usefulness of BAL BDG testing.
We report the development of a PCR-based assay for the detection of microsporidia in clinical specimens. A single primer pair complementary to conserved sequences of the small-subunit rRNA enabled amplification of DNA from the four major microsporidian pathogens of humans: Encephalitozoon cuniculi, Encephalitozoon hellem, Enterocytozoon bieneusi, and Septata intestinalis. The extraction method allowed PCR amplification of E. bieneusi and S. intestinalis DNA from sodium hypochlorite-treated stool specimens. Differentiation of the microsporidian gastrointestinal pathogens E. bieneusi and S. intestinalis could be accomplished by restriction endonuclease digestion of PCR products using PstI and HaeIII.
SYNOPSIShepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis testing (oral or written) and for contact tracing (oral) was obtained. Case Definition, Case Finding, and Contact TracingWe defined an outbreak-related case as a newly diagnosed laboratory-confirmed HIV infection, with evidence of acute infection suggesting occurrence of transmission on December 30, 2016, among women who had received LIT at ZC Hospital that day or their secondary contacts, with HIV gene sequence highly related to that of the index casepatient. Initial case finding began among all women who received LIT at ZC Hospital on December 30. A trained public health specialist conducted interviews on HIV risk behavior during December 30, 2016-January 25, 2017, to assess the possibility that HIV infection had been acquired by means other than LIT and that HIV already had been transmitted to others. HIV, HBV, HCV, and Syphilis TestingAll potential outbreak-related case-patients and their contacts were provided free testing and counseling at ZC Hospital. Persons in whom HIV infection was diagnosed were referred to treatment. For HIV, serologic screening was conducted at ZC Hospital's laboratory using the Anti-HIV (1+2) 4th-generation antigen/antibody enzyme immunoassay (EIA) kit (Shanghai Kehua Bio-Engineering, Shanghai, China) and the HIV 1/2/O Tri-Line HIV Rapid Test Device (ABON Biopharm, Hangzhou). If reactive, new venous blood specimens were collected and sent to the Hangzhou Center for Disease Control and Prevention laboratory for confirmatory serologic testing by Western blot (WB; MP Biomedicals, Singapore). In parallel, plasma specimens were sent to the Zhejiang CDC, where HIV nucleic acid testing was conducted using COBAS AmpliPrep/COBAS TaqMan HIV-1 Test v2.0 kits (Roche, Branchburg, NJ, USA).HBV, HCV, and syphilis testing were performed at ZC Hospital's laboratory. For HBV, samples were screened for 5 indicators (i.e., hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B e-antigen, hepatitis B e-antibody, hepatitis B c-antibody) using EIA kits (InTec Products, Xiamen, China). For HCV, samples were screened for antibodies using an EIA kit (Zhuhai Livzon Diagnostics, Zhuhai, China). For syphilis, samples were initially screened by Toluidine Red Untreated Serum Test (TRUST, Shanghai Rongsheng Biotech, Shanghai, China). Reactive samples were confirmed by Treponema pallidum particle agglutination assay (Fujirebio Inc., Nagasaki, Japan). Laboratory AuditAn audit of the hospital laboratory began immediately on January 25 and lasted 6 days. It was conducted by 3 trained 2144
We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) for the rapid identification of anaerobic bacteria that had been isolated from clinical specimens and previously identified by 16s rRNA sequencing. The Bruker Microflex MALDI-TOF instrument with the Biotyper Software was used. We tested 152 isolates of anaerobic bacteria from 24 different genera and 75 different species. A total of 125 isolates (82%) had Biotyper software scores greater than 2.0 and the correct identification to genus and species was made by MALDI-TOF for 120 (79%) of isolates. Of the 12 isolates with a score between 1.8 and 2.0, 2 (17%) organisms were incorrectly identified by MALDI-TOF. Only 15 (10%) isolates had a score less than 1.8 and MALDI-TOF gave the wrong genus and species for four isolates, the correct genus for two isolates, and the correct genus and species for nine isolates. Therefore, we found the Bruker MALDI-TOF MicroFlex LT with an expanded database and the use of bacteria extracts rather than whole organisms correctly identified 130 of 152 (86%) isolates to genus and species when the cut-off for an acceptable identification was a spectrum score ≥1.8.
Corynebacterium striatum is a rare, but likely underreported, cause of serious infections in immunocompromised hosts and generally is susceptible to multiple classes of antimicrobial agents. Here we report the first case of C. striatum infection in a solid organ transplant recipient. Three years after heart transplantation, a 58-year-old man developed bilateral pneumonia and pulmonary embolism. He did not improve with levofloxacin, piperacillin/tazobactam, and heparin treatment. A homogeneous population of abundant gram-positive rods was repeatedly demonstrated in sputum and bronchoalveolar lavage fluid, and C. striatum was grown in pure culture. The isolate was unusual for its multidrug-resistant (MDR) antimicrobial susceptibility pattern. The pneumonia resolved with 4 weeks of vancomycin therapy, in combination with rifampin given only during the first 2 weeks of treatment. The isolation of coryneforms ("diphtheroids") is often attributed to contamination. Their abundant presence on direct examination of specimens and/or their growth in pure culture suggest a pathogenic role, however, and indicate the need for accurate microbiological identification, particularly in immunocompromised hosts who have been hospitalized and previously treated with antibiotics. Combination therapy that includes vancomycin may be the most prudent treatment for MDR C. striatum infections.
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