Rapid bacterial identification by MALDI-TOF MS directly from blood cultures and rapid susceptibility testing: A simple approach to reduce the turnaround time of blood cultures

Abstract Antimicrobial treatment of patients with bloodstream infections (BSI) is time-sensitive. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility are critical for targeted therapy early in the disease course. This study describes the performance of a rapid method for identifying and testing antimicrobial susceptibility of Gram-negative bacteria performed directly from blood culture bottles in a routine microbiology laboratory. A total of 284, 120, and 24 samples were analyzed by rapid identification (Rid), rapid susceptibility testing (RAST), and rapid broth microdilution for polymyxin B (rMIC), respectively, and compared with standard methods. Our protocol was able to identify 93% of isolates at the species level using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We obtained 100% agreement for RAST compared to the standard method and 96% agreement for rMIC. Our protocol has proven to be an excellent tool for rapid identification of Gram-negative bacilli causing BSIs. It can also be used in microbiology laboratory routine along with RAST and faster polymyxin microdilution, especially for carbapenemase-producing bacteria, allowing for rapid, simple, accurate, and cost-effective diagnosis.

Fusarium solani keratitis: role of antifungal susceptibility testing and identification to the species level for proper management

ABSTRACT We report a patient with fungal keratitis caused by a multiresistant Fusarium solani in a tertiary care hospital located in southern Brazil. A 55-year-old man with a history of ocular trauma presented with keratitis in left eye. The patient has a complicated clinical course and failed to respond to local and systemic antifungal treatment, and required eye enucleation. Despite multiple topical, intraocular and systemic antifungal treatments, hyphal infiltration persisted in the corneal transplant causing continuous recurrences. The cultures of corneal biopsy scrapings were positive for Fusarium spp. The organism was identified to species level by multi-locus sequencing for translation elongation factor 1 alpha (EF-1α), and RNA polymerase II subunit (RPB2). In vitro antifungal susceptibility testing of the isolate by the broth microdilution method, according to CLSI M38-A2, disclosed susceptibility to natamycin and resistance to amphotericin B, voriconazole, itraconazole and fluconazole. Considering previous unsuccessful antifungal treatments due to multiple drug resistance, the eye was enucleated. Our case report illustrates that management of fungal keratitis remains a therapeutic challenge. Optimal treatment for F. solani infection has not yet been established and should include susceptibility testing for different antifungal agents.

Ciguatera fish poisoning in Brazilian traveler to Caribbean

ABSTRACT Ciguatera poisoning is the most common form of non-bacterial food-poisoning from fish worldwide. The incidence among Brazilians returning from high-risk regions is unclear because it is not a mandatory reportable disease. We describe a previously healthy 53-year-old Brazilian woman developed Ciguatera fish poisoning while traveling to Havana, Cuba. Physicians and health care professionals should advise travelers to avoid eating ciguatoxic fish species and potentially toxic fish species in the Caribbean islands. Despite the prognosis for most cases is good with a short duration of self-limited symptoms, early recognition of the identifying clinical features of ciguatera can result in improved patient care.

Epidemiology and clinical characteristics of herpes zoster in a tertiary care hospital in Brazil

ABSTRACT Background: There is little information on herpes zoster from hospital registries in South America. The aim of this study was to describe the epidemiological and clinical aspects of herpes zoster (HZ) in hospitalized patients.' Methods: We searched for hospital-based records during the period from March 2000 to January 2017 in a 700-bed tertiary-care hospital located in southern Brazil. The medical records of all eligible patients were reviewed, and data regarding demographics, medical history, clinical and laboratory characteristics, treatment regimens, and clinical outcomes were collected. Patients were also evaluated for mortality. Results: There were 801 records of herpes zoster according to the proposed criteria. Most patients with HZ presented a cutaneous clinical form of the disease with involvement of a single dermatome (n = 589, 73.5%). Additional clinical characteristics included postherpetic neuralgia (22.1%), ophthalmic HZ (7.6%) and meningoencephalitis (2.7%). Most patients presented immunocompromised conditions (64.9%) including HIV, administration of immunosuppressive agents, and malignant neoplasms. During this period, there were 105 (13.1%) deaths, which were mostly unrelated to HZ. Five deaths were related to HZ meningoencephalitis. Conclusion: The results of this study demonstrate a high burden of HZ disease in a Brazilian tertiary care hospital in the HZ vaccination era. Awareness of the incidence and comorbidity factors associated with HZ in Latin American countries such as Brazil contribute for adoption and implementation of strategies for immunization in this area.

Molecular types of Cryptococcus species isolated from patients with cryptococcal meningitis in a Brazilian tertiary care hospital

ABSTRACT There are limited data on the molecular epidemiology of cryptococcosis in Brazil. Here, we report on the identification of the molecular pattern of the Cryptococcus species that caused meningitis in patients admitted in a Brazilian reference tertiary care hospital, and review the published studies addressing the molecular epidemiology of Cryptococcus in Brazil. Our study has shown the predominance of molecular type VNII in HIV-infected patients with cryptococcal meningoencephalitis. Molecular types VNII and VGII were occasionally detected in HIV-infected and non-infected patients with meningoencephalitis. In contrast, previous studies have shown that several regions exhibited a high prevalence of the VNI molecular type and sporadic cases of the VNII and VGII molecular types in patients with cryptococcosis in Brazil. Additional studies including VNII isolates will contribute to understanding the epidemiology and phylogenetic relationship of these genotype compared to the other ones. So far, no clear correlation has been established between genotypes, antifungal susceptibility for Cryptococcus and clinical outcome in cryptococcosis.

Consensus of the Brazilian Society of Infectious Diseases and Brazilian Society of Clinical Oncology on the management and treatment of Kaposi's sarcoma

Kaposi's sarcoma is a multifocal vascular lesion of low-grade potential that is most often present in mucocutaneous sites and usually also affects lymph nodes and visceral organs. The condition may manifest through purplish lesions, flat or raised with an irregular shape, gastrointestinal bleeding due to lesions located in the digestive system, and dyspnea and hemoptysis associated with pulmonary lesions. In the early 1980s, the appearance of several cases of Kaposi's sarcoma in homosexual men was the first alarm about a newly identified epidemic, acquired immunodeficiency syndrome. In 1994, it was finally demonstrated that the presence of a herpes virus associated with Kaposi's sarcoma called HHV-8 or Kaposi's sarcoma herpes virus and its genetic sequence was rapidly deciphered. The prevalence of this virus is very high (about 50%) in some African populations, but stands between 2% and 8% for the entire world population. Kaposi's sarcoma only develops when the immune system is depressed, as in acquired immunodeficiency syndrome, which appears to be associated with a specific variant of the Kaposi's sarcoma herpes virus. There are no treatment guidelines for Kaposi's sarcoma established in Brazil, and thus the Brazilian Society of Clinical Oncology and the Brazilian Society of Infectious Diseases developed the treatment consensus presented here.

Autologous transplant: microbial contamination of hematopoietic stem cell products

Hematopoietic progenitor cells from peripheral blood (HPCPB) are commonly used for autologous and allogenic transplants in patients with most various onco-hematological diseases, and despite the utilization of sterile techniques during collection and processing of these products, bacterial contamination can occur. This study aimed to investigate the microbial contamination of HPCPB products. Microbial cultures of 837 HPCPB products between the year 2000 and 2009 were retrospectively analyzed to determine the incidence of culture positivity and identify the main organisms that cause contamination. The microbiological studies were performed with an automated system (BacT/Alert® bioMérieux Corporate). Thirty-six (4.3%) of 837 microbial cultures were contaminated. Coagulase-negative Staphylococcus was the most frequent bacteria isolated from HPCPB products (20 [56%] of the 36 positive microbial cultures). Considering the 36 contaminated samples, 22 HPCPB products were infused and 14 discarded. Pre-and post-infusion antibiotic therapy of the patients transfused with contaminated products was established based on the isolated microorganism and its antibiogram. Microbial contamination rate of HPCPB products was low. Clinically significant outcomes after infusion of contaminated HPCPB products were not observed.

Previous use of quinolones: a surrogate marker for first line anti-tuberculosis drugs resistance in HIV-infected patients?

OBJECTIVES: Drug resistant Mycobacterium tuberculosis causes much higher rates of treatment toxicity, failure or relapse, and mortality. We determined the drug resistant profile of Mycobacterium tuberculosis strains isolated from a population of HIV-infected patients in southern Brazil and studied the potential factors associated with resistance. METHODS: We conducted a retrospective cohort study to determine the resistance profile of Mycobacterium tuberculosis isolated from HIV-infected patients and factors that could be associated with resistance from 2000 to 2005. RESULTS: 236 patients were included in the study. Resistance to at least one drug was observed in 32 (14.6%) isolates, and multi-drug resistance was observed in 4 (1.82%) isolates. On multivariate analysis, previous use of tuberculostatics and quinolones were related to any first-line drug resistance. CONCLUSIONS: In our study, previous quinolone use was significantly associated to first-line anti-TB drugs resistance. Multi-drug-resistant tuberculosis (MDR-TB) is a major problem worldwide, and we believe quinolones should be used with caution in settings where TB is endemic.

Candida tropicalis as an emerging pathogen in Candida meningitis: case report and review

Candida species are an uncommon cause of meninigitis. Given the rarity of this infection, the epidemiology, prognosis, and optimal therapy for Candida meningitis are poorly defined. The authors report on a paraplegic patient due to spinal cord injury who developed C. tropicalis meningitis. In addition, we review and discuss other reported cases of C. tropicalis meningitis in the medical literature.

Polymerase chain reaction as a useful and simple tool for rapid diagnosis of tuberculous meningitis in a Brazilian tertiary care hospital

Meningitis is a severe and potentially fatal form of tuberculosis. The diagnostic workup involves detection of acid-fast bacilli (AFB) in the cerebrospinal fluid (CSF) by microscopy or culture, however, the difficulty in detecting the organism poses a challenge to diagnosis. The use of the polymerase chain reaction (PCR) in the diagnostic approach to Mycobacterium tuberculosis (MTB) meningitis has been reported as a fast and accurate method, with several commercial kits available. As an alternative, some institutions have been developing inexpensive in house assays. In our institution, we use an in house PCR for tuberculosis. We analyzed the performance of our PCR for the diagnosis of MTB meningitis in 148 consecutive patients, using MTB culture as gold standard. The sensitivity and specificity of CSF PCR for the diagnosis of MTB meningitis was 50 percent and 98.6 percent respectively with a concordance with CSF mycobacterial culture of 96 percent (Kappa=0.52). In contrast to CSF cultures for MTB, our PCR test is a fast, simple and inexpensive tool to diagnose tuberculous meningitis with a performance similar to that obtained with the available commercial kits.

Prevalence, susceptibility profile for fluconazole and risk factors for candidemia in a tertiary care hospital in southern Brazil

Bloodstream infections caused by yeast, Candida spp, are quite important clinically and epidemiologically due to a high mortality rate and an increasing number of non-albicans species with a more resistant (differentiated susceptibility) profile. We examined species prevalence and susceptibility profile for fluconazole and the risk for nosocomial infections by Candida spp at the Hospital de Clínicas de Porto Alegre, a general tertiary care hospital in southern Brazilian, through a retrospective study, beginning with positive cultures of hospitalized patients. The distribution by species in 131 documented episodes was as follows: Candida albicans (45 percent), C. parapsilosis (24.4 percent), C. tropicalis (15.3 percent), C. glabrata (6.9 percent), C. krusei (4.6 percent) and 3.8 percent other species (C. pelicullosa, C. guilliermondii, C. lusitaniae and C. kefyr). The vast majority of samples (121- 92.4 percent) were susceptible to fluconazole; the resistant or dose-dependent sensitive samples included only C. krusei and C. glabrata. Blood diseases (leukemia, lymphoma), or neoplasias (solid tumors), were found in 35.0 percent of the candidemia episodes. We noted the previous use of antibiotics in 128 (97.7 percent) patients, with 79.7 percent using three or more antibiotics before the candidemia episode. Other risk factors included a central venous catheter in 94 (71.8 percent) and abdominal surgery in 32 (24.4 percent) patients. The overall mortality rate was 51.9 percent, which varied according to the underlying disease. We found that C. albicans was the most prevalent species, although the non-albicans species predominated. However, in vitro resistance to fluconazole was detected only among the species (C. glabrata and C. krusei) that tend to be resistant to the azolic compounds. Previous use of antibiotic and the use of a central venous catheter were the main risk factors among patients with candidemia.