Clinical and mycological analysis of colonization by Candida spp. in oral leukoplakia and oral lichen planus.

OBJECTIVE: This study aims to analyze the prevalence of Candida spp. colonization in oral leukoplakia and oral lichen planus lesions, verify the influence of systemic and local factors, besides identify and determine the in vitro antifungal susceptibility profile of Candida species. MATERIALS AND METHODS: Samples were collected by swabbing from oral lesions and healthy mucosa and cultured on Sabouraud Dextrose and CHROMagar® Candida plates. Species identification was confirmed with MALDI-TOF MS analysis. RESULTS: Candida spp. was found in 36.8% of cases of oral leukoplakia and 18.2% of cases of oral lichen planus. Candida albicans was the only species found in oral lichen planus lesions (n = 2, 100%) and the most prevalent in oral leukoplakia (n = 5, 76.4%). Among the non-albicans Candida species found in oral leukoplakia were C. parapsilosis (n = 2, 25.5%) and C. tropicalis (n = 1, 14.1%). Candida isolates were susceptible to all antifungals tested. CONCLUSION: C. albicans was the most commonly found species in the studied lesions. No correlation was found between systemic and local factors with positive cases of oral lichen planus. However, smoking and alcohol consumption may be associated with positive cases of oral leukoplakia, especially the non-homogeneous clinical form. In addition, there is a possible predisposition to associated Candida colonization in cases of epithelial dysplasia found in oral leukoplakia. The antifungal medications tested showed excellent efficacy against isolates.

Trichosporon asahii causing subcutaneous mycoses in an immunocompetent patient: case report and a minireview.

Trichosporon spp. are a constituent of the normal flora of humans that can cause both superficial and invasive infections, mainly in immunocompromised and immunocompetent hosts, respectively. Herein, we a report of Trichosporon asahii causing subcutaneous fungal infection (SFI) in an immunocompetent patient after carpal tunnel surgery. Although susceptible to fluconazole, the treatment of SFI failed even using high doses of this azole. The skin lesion improved following the administration of voriconazole. We conducted a literature minireview searching reports on SFI in immunocompetent patients to check for epidemiological, diagnostic, therapeutic, and outcome characteristics. A total of 32 cases were reported. Despite being uncommon, the clinical suspicion and early diagnosis of SFI in immunocompetent patients undergoing previous surgery are important. Our study indicated that the azoles are the most active antifungal agents against Trichosporon spp., except for fluconazole, and voriconazole can be considered the first therapeutic option.

In vitro synergy of ticarcillin/clavulanate in combination with aztreonam and ceftolozane/tazobactam against SPM-1-producing Pseudomonas aeruginosa strains.

Minimal inhibitory concentrations (MICs) of ticarcillin/clavulanic acid (TLc), ceftolozane/tazobactam (C/T), and aztreonam (AT) were determined for 6 SPM-1-producing Pseudomonas aeruginosa (PSA) using Etest® strips and the synergistic effect of such antimicrobials against was evaluated by gradient diffusion strip crossing (GDSC) test. The fraction inhibitory concentration indexes (FICI) were calculated and showed a synergistic (n = 3) and additive (n = 2) effects of TLc + AT against SPM-1 producers, while TLc + C/T combination caused no effect. Average MIC reduction of TLc and AT by GDSC was 3-fold and 2-fold dilutions, respectively. Thus, TLc + AT might be a candidate as a combination therapy to treat SPM-1-producing PSA infections.

Virulence Potential of a Multidrug-Resistant Escherichia coli Strain Belonging to the Emerging Clonal Group ST101-B1 Isolated from Bloodstream Infection.

Escherichia coli EC121 is a multidrug-resistant (MDR) strain isolated from a bloodstream infection of an inpatient with persistent gastroenteritis and T-zone lymphoma that died due to septic shock. Despite causing an extraintestinal infection, previous studies showed that it did not have the usual characteristics of an extraintestinal pathogenic E. coli. Instead, it belonged to phylogenetic group B1 and harbored few known virulence genes. To evaluate the pathogenic potential of strain EC121, an extensive genome sequencing and in vitro characterization of various pathogenicity-associated properties were performed. The genomic analysis showed that strain EC121 harbors more than 50 complete virulence genetic clusters. It also displays the capacity to adhere to a variety of epithelial cell lineages and invade T24 bladder cells, as well as the ability to form biofilms on abiotic surfaces, and survive the bactericidal serum complement activity. Additionally, EC121 was shown to be virulent in the Galleria mellonella model. Furthermore, EC121 is an MDR strain harboring 14 antimicrobial resistance genes, including blaCTX-M-2. Completing the scenario, it belongs to serotype O154:H25 and to sequence type 101-B1, which has been epidemiologically linked to extraintestinal infections as well as to antimicrobial resistance spread. This study with E. coli strain EC121 shows that clinical isolates considered opportunistic might be true pathogens that go underestimated.

In vitro synergy of ceftolozane/tazobactam in combination with fosfomycin or aztreonam against MDR Pseudomonas aeruginosa.

OBJECTIVES: Carbapenem-resistant Pseudomonas aeruginosa (CR-PSA) imposes great limitations on empirical therapeutic choices, which are further complicated by metallo-ß-lactamase production. This study evaluated in vitro antimicrobial synergy of ceftolozane/tazobactam in combination with aztreonam and fosfomycin against MDR PSA. METHODS: MICs were determined by broth microdilution and gradient strips. The effect of ceftolozane/tazobactam+aztreonam and ceftolozane/tazobactam+fosfomycin combinations were tested against 27 MDR PSA isolates carrying blaSPM-1 (n = 13), blaIMP (n = 4), blaVIM (n = 3), blaGES-1 (n = 2) and blaCTX-M-like (n = 2), and 3 isolates with no acquired ß-lactamase production detected by gradient diffusion strip crossing (GDSC). Six genetically unrelated SPM-1-producing isolates were also evaluated by time-kill analysis (TKA). RESULTS: All CR-PSA isolates harbouring blaSPM-1, blaGES-1 and blaIMP-1 were categorized as resistant to ceftolozane/tazobactam, meropenem and fosfomycin, with 70% being susceptible to aztreonam. Synergism for ceftolozane/tazobactam+fosfomycin and ceftolozane/tazobactam+aztreonam combinations was observed for 88.9% (24/27) and 18.5% (5/27) of the isolates by GDSC, respectively. A 3- to 9-fold reduction in ceftolozane/tazobactam MICs was observed, depending on the combination. Ceftolozane/tazobactam+fosfomycin was synergistic by TKA against one of six SPM-1-producing isolates, with additional non-synergistic bacterial density reduction for another isolate. Aztreonam peak concentrations alone demonstrated a ≥3 log10 cfu/mL reduction against all six isolates, but all strains were within the susceptible range for the drug. No antagonism was observed. CONCLUSIONS: In the context of increasing CR-PSA and the genetic diversity of resistance mechanisms, new combinations and stewardship strategies may need to be explored in the face of increasingly difficult to treat pathogens.

Implications of domestic dogs in the epidemiology of Rickettsia parkeri strain Atlantic rainforest and Rangelia vitalii in Southeastern Brazil / Implicações dos cães domésticos na epidemiologia da Rickettsia parkeri cepa Mata Atlântica e da Rangelia vitalii no Sudeste do Brasil

Abstract This study aimed to evaluate the occurrence of diseases transmitted by Amblyomma ovale in 61 dogs monitored for three years through collections of ticks and blood, interviews, telemetry and camera traps in three areas of Serra do Mar State Park, Brazil. Blood samples were used to investigate infection by Rangelia vitalii by real-time TaqMan PCR and Rickettsia parkeri by IIFA. The collected ticks were submitted to conventional PCR to investigate the presence of R. parkeri . These data were compared with the monitoring results and interviews with the owners. Dogs considered as companion presented a risk of infection by R. parkeri strain Mata Atlantica 5.4 times higher than those not considered as companion (p = 0.009). Dogs that had at least one A. ovale collected during the campaigns had a 10 times higher risk of infection by R. parkeri strain Mata Atlantica than those who did not (p = 0.009). One dog positive for R. vitalii by real-time TaqMan PCR was parasitized by A. ovale frequently during monitoring. Sequenced ompaA - positive DNA samples had 100% identity of R. parkeri strain Mata Atlantica clone As106. From the findings, it is urgent to control domestic dogs around rainforests to reduce zoonoses transmission.

Resumo A ocorrência de doenças transmitidas por Amblyomma ovale em 61 cães monitorados por três anos através de coletas de carrapatos, sangue, entrevistas, telemetria e armadilhas fotográficas foi avaliada em três áreas do Parque Estadual da Serra do Mar - SP. Amostras de sangue foram utilizadas para investigação de Rangelia vitalii através de PCR TaqMan em tempo real e Rickettsia parkeri através da RIFI. Carrapatos coletados foram submetidos à PCR convencional para investigação de R. parkeri . Estes dados foram comparados considerando os resultados do monitoramento e entrevistas. Cães de companhia apresentaram risco de infecção pela R. parkeri cepa Mata Atlântica 5,4 vezes maior que os não considerados como de companhia (p = 0,009). Cães que tiveram pelo menos um A. ovale coletado apresentaram risco de infecção por R. parkeri cepa Mata Atlântica 10 vezes maior do que aqueles que não tiveram (p = 0,009). Um cão positivo para R. vitalii através de PCR TaqMan em tempo real foi parasitado por A. ovale durante o monitoramento. Amostras positivas para o gene ompaA possuíam 100% de identidade do clone As106 de R. parkeri cepa de Mata Atlântica. Assim, é urgente o controle de cães na Mata Atlântica para redução dos riscos de zoonoses.

Diversity of metallo-b-lactamase-encoding genes found in distinct species of Acinetobacter isolated from the Brazilian Amazon Region

BACKGROUND The multidrug resistance (MDR) phenotype is frequently observed in Acinetobacter baumannii, the most clinically relevant pathogenic species of its genus; recently, other species belonging to the A. calcoaceticus-A. baumannii complex have emerged as important MDR nosocomial pathogens. OBJECTIVES The present study aimed to verify the occurrence of metallo-β-lactamase genes among distinct Acinetobacter species in a hospital located in the Brazilian Amazon Region. METHODS Antimicrobial susceptibility profiles were determined by broth microdilution. The genetic relationships among these isolates were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Pyrosequencing reads of plasmids carrying the bla NDM-1 gene were generated using the Ion Torrent™ platform sequencing. FINDINGS A total of six isolates carried bla NDM-1: A. baumannii (n = 2), A. nosocomialis (n = 3), and A. pittii (n = 1); three carried bla IMP-1: A. baumannii, A. nosocomialis, and A. bereziniae. Resistance to colistin was observed for an NDM-1-producing A. nosocomialis isolate. Diverse PFGE patterns and sequence types were found among A. nosocomialis and A. baumannii isolates. The bla NDM-1 sequence was inserted in a Tn125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In86. MAIN CONCLUSIONS To the best of our knowledge, this is the first report describing the dissemination of bla NDM-1 among distinct Acinetobacter species recovered from the same hospital in South America.

Temporal evolution of antimicrobial resistance among Neisseria gonorrhoeae clinical isolates in the most populated South American Metropolitan Region

A total of 124 Neisseria gonorrhoeae isolates recovered during a 12-year period (2003-2015) from outpatients assisted at Centro de Referência e Treinamento DST/AIDS-CRT of São Paulo city, Brazil, were analysed. The following resistance rates were observed: penicillin-59.6%, ciprofloxacin-15.3%, and azithromycin-6.7%. Although reduced susceptibility to these drugs was observed since 2003, no ceftriaxone-resistant isolates were detected. Ciprofloxacin- and azithromycin non-susceptible isolates were grouped in 11 clusters. Mutations were detected in GyrA and ParC of isolates 124 and 260, and a C2611T substitution on 23S rRNA alleles was also observed in isolate 260. Both isolates belonged to ST1901/ST6210 (MSLT/NG-MAST schemes).

Early dissemination of OXA-72-producing Acinetobacter baumannii strain in Colombia: a case report

Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reached epidemic levels in past decades. Currently this microorganism is responsible for outbreaks of difficult eradication and with high mortality rates worldwide. We herein report a rare case of an OXA-72-producing A. baumannii isolate colonizing a 47-year-old male patient with peritonitis due to abdominal stab wound, four years earlier than the first report of this carbapenemase in Acinetobacter pittii in Colombia. Although OXA-72 presents a low prevalence compared with OXA-23, our study demonstrated that A. baumannii isolates carrying the blaOXA-72 gene were present in the hospital environment in Colombia and could act as a reservoir for further spread to other Acinetobacter species, like A. pittii, causing carbapenem-resistance.

Evaluation of MALDI-TOF MS in the microbiology laboratory / Avaliação da técnica de MALDI-TOF MS no laboratório de microbiologia

Rapid identification of microorganisms by the clinical microbiology laboratory is of crucial importance for optimal patients’ management and treatment. In general, bacterial identification by conventional methods requires 18-24 hours for colony isolation and at least 24 additional hours for species identification. New technologies in microbiology have focused on the rapid diagnosis of bloodstream infections, since they are associated with high morbidity and mortality rates.

A rápida identificação de microrganismos no laboratório de microbiologia clínica é de extrema importância para direcionar o manejo e o tratamento de pacientes. Geralmente, a identificação bacteriana por métodos bioquímicos convencionais necessita de 18 a 24 horas para o crescimento e o isolamento da colônia bacteriana e, pelo menos, 24 horas adicionais para a identificação da espécie. Novas tecnologias em microbiologia têm focado no desenvolvimento de métodos relacionados com o diagnóstico rápido das infecções da corrente sanguínea, uma vez que essas infecções são associadas à alta morbimortalidade.

Bloodstream infection caused by Acinetobacter junii in a patient with acute lymphoblastic leukaemia after allogenic haematopoietic cell transplantation.

Acinetobacter junii is a rare human pathogen associated with bacteraemia in neonates and paediatric oncology patients. We present a case of A. junii causing bacteraemia in an adult transplant patient with leukaemia. The correct identification of Acinetobacter species can highlight the clinical significance of the different species of this genus.