Monica Souza - Academia.edu (original) (raw)

Papers by Monica Souza

Arquivos de Neuro-Psiquiatria, 2005

Status Dystonicus (SD) is characterized by generalized muscle contractions in dystonic patients. ... more Status Dystonicus (SD) is characterized by generalized muscle contractions in dystonic patients. We report 5 cases of SD, two of which in patients with dystonic cerebral palsy, one in a patient with primary segmental dystonia, one in a patient with Hallervorden-Spatz syndrome and one in a patient with Wilson's disease (WD). Three patients were admitted to an intensive care unit and treated with propofol and midazolam, and two were submitted to neurosurgical procedures (bilateral pallidotomy and bilateral pallidal deep brain stimulation). Triggering factors were identified in three patients as follows: infection, stress-induced and zinc therapy for WD. On follow-up, two patients presented with significant improvement of dystonia, whereas the other three cases the clinical picture ultimately returned to baseline pre-SD condition.

Microbiology and Immunology, 2010

infected with the tox-strain. Host cell death and nuclear alterations were evidenced by the Trypa... more infected with the tox-strain. Host cell death and nuclear alterations were evidenced by the Trypan blue exclusion assay and DAPI fluorescence microscopy. ELISA of histone-associated DNA fragments allowed detection of apoptosis and necrosis induced by tox+ and tox-strains at T-1 hr and T-3 hr. In conclusion, human macrophages in the absence of opsonins may not be promptly effective at killing diphtheria bacilli. The presence of the tox gene influences the susceptibility of C. diphtheriae to human macrophages and the outcome of non-opsonic phagocytosis. C. diphtheriae strains exhibit strategies to survive within macrophages and to exert apoptosis and necrosis in human phagocytic cells, independent of the tox gene.

Memórias do Instituto Oswaldo Cruz, 2009

During a five-year period, 932 clinical isolates from cancer patients treated in a Brazilian refe... more During a five-year period, 932 clinical isolates from cancer patients treated in a Brazilian reference centre were identified as corynebacteria; 86% of the cultures came from patients who had been clinically and microbiologically classified as infected and 77.1% of these patients had been hospitalised (71.1% from surgical wards). The adult solid tumour was the most common underlying malignant disease (66.7%). The univariate and multivariate analyses showed that hospitalised patients had a six-fold greater risk (OR = 5.5, 95% CI = 1.15-26.30 p = 0.033) related to 30-day mortality. The predominant species were Corynebacterium amycolatum (44.7%), Corynebacterium minutissimum (18.3%) and Corynebacterium pseudodiphtheriticum (8.5%). The upper urinary tracts, surgical wounds, lower respiratory tracts, ulcerated tumours and indwelling venous catheters were the most frequent sources of C. amycolatum strains. Corynebacterium jeikeium infection occurred primarily in neutropenic patients who have used venous catheters, while infection caused by C. amycolatum and other species emerged mainly in patients with solid tumours.

Letters in Applied Microbiology, 2008

To examine the value of the DNase test as an alternative procedure for differentiating Corynebact... more To examine the value of the DNase test as an alternative procedure for differentiating Corynebacterium diphtheriae from Corynebacterium-like colonies. DNase test medium was inoculated by spotting a loopful of bacterial growth and incubated aerobically at 37 degrees C. The DNase production was detectable following both 24 and 48 h incubation periods. The DNase activity was detected in all 91 C. diphtheriae (37 toxigenic and 54 nontoxigenic) strains examined, previously identified by both conventional biochemical methods and API Coryne System. Conversely, DNase test results were negative in 93.9% of the 564 nondiphtherial Gram-positive rod clinical strains. The DNase test emerged as an easily interpretable and cost-effective alternative screening procedure for C. diphtheriae laboratory identification. The method should facilitate routine laboratory diagnosis of toxigenic and nontoxigenic C. diphtheriae.

Letters in Applied Microbiology, 2009

Aims: To examine the occurrence of and to determine the antimicrobial susceptibility of Corynebac... more Aims: To examine the occurrence of and to determine the antimicrobial susceptibility of Corynebacterium pseudodiphtheriticum among patients with bacterial infections at a teaching hospital. Methods and Results: A total of 113 Coryne. pseudodiphtheriticum strains identified by conventional biochemical methods and API-Coryne System were recovered from patients from different age groups: 65AE48% adults (18 to £59 years old), 9AE73% aged ( ‡60 years old); 14AE15% infants (<18 years old); 4AE42% newborns (0-7 days). Micro-organisms were mostly related to infections in the urinary (29AE2%) and respiratory tracts (27AE45%) and intravenous sites (18AE6%). Clinical samples were obtained only from 32AE7% patients (26 adults, four aged, four infants and three newborns) presenting at least one of the predisposing conditions: end-stage renal disease; renal transplant; AIDS and Mycobacterium tuberculosis infection; cancer, hepatic cirrhosis; haemodialysis and catheter use. Antimicrobial susceptibility tests identified multiresistant phenotypes. Most strains (>50%) were resistant to oxacillin, erythromycin and clindamycin. Conclusions: Despite significant differences in age and functional status of patients Coryne. pseudodiphtheriticum may be implicated as a cause of respiratory and nonrespiratory human infections. Significance and Impact of the Study: Data are valuable for practitioners indicating the occurrence of multiresistant phenotypes and the possibility of severe infections due to Coryne. pseudodiphtheriticum, a pathogen usually overlooked in emerging countries.

Journal of Medical Microbiology, 2009

Corynebacterium diphtheriae still represents a global medical challenge, particularly due to the ... more Corynebacterium diphtheriae still represents a global medical challenge, particularly due to the significant number of individuals susceptible to diphtheria and the emergence of non-toxigenic strains as the causative agents of invasive infections. In this study, we characterized the clinical and microbiological features of what we believe to be the first case of C. diphtheriae infection of a percutaneous nephrostomy catheter insertion site in an elderly patient with a fatal bladder cancer. Moreover, we demonstrated the potential role of adherence, biofilm formation and fibrin deposition traits in C. diphtheriae from the catheter-related infection. Non-toxigenic C. diphtheriae isolated from the purulent discharge (named strain BR-CAT5003748) was identified by the API Coryne system (code 1 010 324) and a multiplex PCR for detection of dtxR and tox genes. Strain BR-CAT5003748 showed resistance to oxacillin, ceftazidime and ciprofloxacin. In experiments performed in vitro, the catheter isolate was classified as moderately hydrophobic and as moderately adherent to polystyrene surfaces. Glass provided a more effective surface for biofilm formation than polystyrene. Micro-organisms adhered to (.1.5¾10 6 c.f.u.) and multiplied on surfaces of polyurethane catheters. Microcolony formation (a hallmark of biofilm formation) and amorphous accretions were observed by scanning electron microscopy on both external and luminal catheter surfaces. Micro-organisms yielded simultaneous expression of localized adherence-like and aggregative-like (LAL/AAL) adherence patterns to HEp-2 cells. Interestingly, the coagulase tube test resulted in the formation of a thin layer of fibrin embedded in rabbit plasma by the non-toxigenic BR-CAT5003748 strain. In conclusion, C. diphtheriae should be recognized as a potential cause of catheter-related infections in at-risk populations such as elderly and cancer patients. LAL/AAL strains may be associated with virulence traits that enable C. diphtheriae to effectively produce biofilms on catheter surfaces. Biofilm formation and fibrin deposition could have contributed to the persistence of C. diphtheriae at the infected insertion site and the obstruction of the nephrostomy catheter.

Journal of Applied Microbiology, 2000

Aims: The aim of this study was to investigate the influence of low iron availability on biofilm ... more Aims: The aim of this study was to investigate the influence of low iron availability on biofilm formation and adherence to HEp-2 cells of enteroaggregative Escherichia coli (EAEC) strains isolated from diarrhoea cases. Methods and Results: The ability of EAEC to form biofilm on a plastic surface was evaluated quantitatively and qualitatively after 3 and 18 h of incubation of strains with or without the iron chelator 2,2-dipyridyl. When submitted to low iron conditions, prototype EAEC 042 strain showed a decrease in biofilm formation. Conversely, an increase in biofilm formation was observed for the clinical EAEC strains cultured in restricted iron condition. Moreover, the reduction of iron concentration inhibited the aggregative adherence to HEp-2 cells of all EAEC strains tested. However, all effects promoted by iron chelation were suppressed by thiourea. Conclusions: Low iron availability may modulate biofilm formation and adhesive properties of EAEC strains to HEp-2 cells. Significance and Impact of the Study: The data obtained in this study provide useful insights on the influence of low iron conditions possibly associated with redox stress on the pathogenesis of EAEC strains.

Memórias do Instituto Oswaldo Cruz, 2012

Corynebacterium pseudodiphtheriticum is a well-known human pathogen that mainly causes respirator... more Corynebacterium pseudodiphtheriticum is a well-known human pathogen that mainly causes respiratory disease and is associated with high mortality in compromised hosts. Little is known about the virulence factors and pathogenesis of C. pseudodiphtheriticum. In this study, cultured human epithelial (HEp-2) cells were used to analyse the adherence pattern, internalisation and intracellular survival of the ATCC 10700 type strain and two additional clinical isolates. These microorganisms exhibited an aggregative adherence-like pattern to HEp-2 cells characterised by clumps of bacteria with a "stacked-brick" appearance. The differences in the ability of these microorganisms to invade and survive within

Memórias do Instituto Oswaldo Cruz, 2013

Corynebacterium striatum is a potentially pathogenic microorganism with the ability to produce ou... more Corynebacterium striatum is a potentially pathogenic microorganism with the ability to produce outbreaks of nosocomial infections. Here, we document a nosocomial outbreak caused by multidrug-resistant (MDR) C. striatum in Rio de Janeiro, Brazil. C. striatum identification was confirmed by 16S rRNA and rpoB gene sequencing. Fifteen C. striatum strains were isolated from adults (half of whom were 50 years of age and older). C. striatum was mostly isolated in pure culture from tracheal aspirates of patients undergoing endotracheal intubation procedures. The analysis by pulsed-field gel electrophoresis (PFGE) indicated the presence of four PFGE profiles, including two related clones of MDR strains (PFGE I and II). The data demonstrated the predominance of PFGE type I, comprising 11 MDR isolates that were mostly isolated from intensive care units and surgical wards. A potential causal link between death and MDR C. striatum (PFGE types I and II) infection was observed in five cases.

Vector-borne and Zoonotic Diseases, 2010

Corynebacterium ulcerans was isolated from nares of one asymptomatic dog kept in an animal shelte... more Corynebacterium ulcerans was isolated from nares of one asymptomatic dog kept in an animal shelter in the metropolitan area of Rio de Janeiro, Brazil. The RNA polymerase beta subunit-encoding gene was sequenced to confirm the species identity. C. ulcerans strains producing phospholipase D, but not diphtheria toxin, are able to cause severe disease in humans, such as pneumonia and granulomatous nodules in pulmonary tissues. The infection rate varies really widely by region, probably because of the variations in the reported infection rates. Dogs with unapparent C. ulcerans infections may be considered as potentially capable of infecting other animals and humans, including pet owners. Medical and veterinary staff should be aware that asymptomatic animals can carry C. ulcerans and cooperate in eliminating infections and monitoring animals also in the developing countries.