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Ariana, Tunisia

Kothavade R.J.,Microbiology Laboratory | Kothavade R.J.,Sir Jj Group Of Hospitals | Dhurat R.S.,LTM Medical College | Mishra S.N.,Venereology and Leprology | Kothavade U.R.,University of Alberta
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2013

Rapidly growing mycobacteria (RGM) are known to cause pulmonary, extra-pulmonary, systemic/disseminated, and cutaneous and subcutaneous infections. The erroneous detection of RGM that is based solely on microscopy, solid and liquid cultures, Bactec systems, and species-specific polymerase chain reaction (PCR) may produce misleading results. Thus, inappropriate therapeutic measures may be used in dermatologic settings, leading to increased numbers of skin deformity cases or recurrent infections. Molecular tools such as the sequence analyses of 16S rRNA, rpoB and hsp65 or PCR restriction enzyme analyses, and the alternate gene sequencing of the superoxide dismutase (SOD) gene, dnaJ, the 16S-23S rRNA internal transcribed spacers (ITS), secA, recA1, dnaK, and the 32-kDa protein gene have shown promising results in the detection of RGM species. PCR restriction enzyme analyses (PRA) work better than conventional methods at identifying species that are closely related. Recently introduced molecular tools such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), pyrosequencing, DNA chip technology, and Beacon probes-combined PCR probes have shown comparable results in the detection of various species of RGM. Closely related RGM species (e.g., Mycobacterium fortuitum, M. chelonae, and M. abscessus) must be clearly differentiated using accurate molecular techniques because their therapeutic responses are species-specific. Hence, this paper reviews the following aspects of RGM: (i) its sources, predisposing factors, clinical manifestations, and concomitant fungal infections; (ii) the risks of misdiagnoses in the management of RGM infections in dermatological settings; (iii) the diagnoses and outcomes of treatment responses in common and uncommon infections in immunocompromised and immunocompetent patients; (iv) conventional versus current molecular methods for the detection of RGM; (v) the basic principles of a promising MALDI-TOF MS, sampling protocol for cutaneous or subcutaneous lesions and its potential for the precise differentiation of M. fortuitum, M. chelonae, and M. abscessus; and (vi) improvements in RGM infection management as described in the recent 2011 Clinical and Laboratory Standards Institute (CLSI) guidelines, including interpretation criteria of molecular methods and antimicrobial drug panels and their break points [minimum inhibitory concentrations (MICs)], which have been highlighted for the initiation of antimicrobial therapy. © 2012 Springer-Verlag Berlin Heidelberg.

Repetto E.C.,University of Brescia | Giacomazzi C.G.,Microbiology Laboratory | Castelli F.,University of Brescia
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2012

Fungi can cause severe infections. Two or more nosocomial unusual fungal infections diagnosed in a short period should be assumed as an outbreak. The review's aim was to collect data to improve their management. The free online worldwide database for nosocomial outbreaks (http://www.outbreak-database.com) and the PubMed/MEDLINE database were used to collect the English literature published from 1990 to June 2011. The more common Candida spp. and Aspergillus spp. infections were excluded. For each outbreak, the following data were reviewed: species, duration, source and site of infection, ward, risk factors, number of patients infected, treatment, related mortality, type of epidemiological study and time elapsed between index cases and second cases. Thirty-six reports were considered: yeasts caused the majority of the outbreaks (16 out of 36). The median values for the overall duration, number of infected people per outbreak and infection-related mortality were 5 months, 4 and 20 %, respectively. Eighteen cases were caused by contaminated substances and 13 cases were hypothesised as human-transmitted. Nosocomial outbreaks due to rare fungal pathogens involve few patients but have high related mortality. These results could be explained by the diagnostic delay, the inability of recognising the source of the infections and the challenges of the treatment. More efforts should be concentrated to implement the application of proper hygiene practices to avoid human-human transmission. © 2012 Springer-Verlag.

In this study it was aimed to investigate the antibiotic susceptibilities and extended spectrum beta lactamase production of Escherichia coli strains isolated from various clinical samples sent to Tavsanli State Hospital Microbiology Laboratory retrospectively. Material and Method: All of the cultures were examined for the agent and antibiotic susceptibilities. For the identification of bacteria, various chemical tests and BBL Crystal E/NF (Beckton Dickinson, ABD) system was used. Antibiotic susceptibilities were investigated according to CLSI criteria on Mueller Hinton agar by disc diffusion method. Double disc synergy method was used to investigate extended spectrum beta lactamase (ESBL) production. Results: 456 E. coli strains isolated from clinical samples were included in the study. E. coli strains were mostly isolated from urine according to clinical samples. The most effective antibiotics against E. coli strains were imipenem, amikacine and sulbactam/cefoperazone. The least susceptibility was against ampicillin. ESBL production rate was found to be %15 in E. coli. Discussion: ESBL producing E. coli which are the reason of expensive therapy and difficulties in treatment of infections should be monitored for ESBL production ratios by all of the centers, extended spectrum beta lactam antibiotics should bu used carefully in treatment, hospitalized patients should be isolated and surveillance should be done in the units under risk.

Achermann Y.,Infectious Diseases Service | Achermann Y.,University of Zurich | Vogt M.,Infectious Diseases Service | Leimig M.,Schulthess Clinic | And 2 more authors.
Journal of Clinical Microbiology | Year: 2010

The microbiological diagnosis of periprosthetic joint infection (PJI) is crucial for successful antimicrobial treatment. Cultures have limited sensitivity, especially in patients receiving antibiotics. We evaluated the value of multiplex PCR for detection of microbial DNA in sonication fluid from removed orthopedic prostheses. Cases of PJI in which the prosthesis (or part of it) was removed were prospectively included. The removed implant was sonicated, and the resulting sonication fluid was cultured and subjected to multiplex PCR. Of 37 PJI cases (17 hip prostheses, 14 knee prostheses, 4 shoulder prostheses, 1 elbow prosthesis, and 1 ankle prosthesis), pathogens were identified in periprosthetic tissue in 24 (65%) cases, in sonication fluid in 23 (62%) cases, and by multiplex PCR in 29 (78%) cases. The pathogen was detected in 5 cases in sonication fluid only (Propionibacterium acnes in all cases. none of these patients had previously received antibiotics) and in 11 cases by multiplex PCR only (all of these patients had previously received antibiotics). After exclusion of 8 cases caused by P. acnes or Corynebacterium species, which cannot be detected due to the absence of specific primers in the PCR kit, sonication cultures were positive in 17 cases and multiplex PCR sonication cultures were positive in 29 cases (59% versus 100%, respectively; P < 0.01). Among 19 cases (51%) receiving antibiotics, multiplex PCR was positive in all 19 (100%), whereas sonication cultures grew the organism in 8 (42%) (P < 0.01). Multiplex PCR of sonication fluid is a promising test for diagnosis of PJI, particularly in patients who previously received antibiotics. With modified primer sets, multiplex PCR has the potential for further improvement of the diagnosis of PJI. Copyright © 2010, American Society tor Microbiology. All Rights Reserved.

Dilintas A.,Microbiology Laboratory
Archives of Hellenic Medicine | Year: 2016

Middle East respiratory syndrome (MERS) is a viral respiratory disease caused by a novel coronavirus (MERS-CoV) which was first identified in Saudi Arabia in 2012. The virus appears to be circulating throughout the Arabian Peninsula, primarily in Saudi Arabia, where the majority of cases (>85%) have been reported. Several cases have been reported in many different countries outside the Middle East. MERS-CoV is a zoonotic virus that is transmitted from animals to humans. The origins of the virus are not fully understood, but it is believed to have originated in bats, to have been transmitted to camels sometime in the distant past. The route of transmission from animals to humans is not fully known, but camels are likely to be a major reservoir host for MERS-CoV and an animal source of infection for humans. The virus does not appear to pass easily from person to person unless there is close contact. Clusters of cases have been reported in healthcare facilities, where human-to-human transmission appears to be more probable, especially when infection prevention and control practices are inadequate, but so far, no sustained community transmission has been documented. Typical MERS symptoms include high fever, cough and shortness of breath. Pneumonia is common and gastrointestinal symptoms, including diarrhea, have also been reported. The fatality rate is high (30-40%). So far, neither a vaccine nor effective therapy against the virus is available. Enhancing infection prevention and control awareness and implementation of preventive measures is critical to avoiding spread of the virus. Breaking the human-to-human transmission cycle remains the cornerstone of infection control during MERSCoV outbreaks. In order to succeed, this requires the effective identification and isolation of cases, and promotion of the necessary trust between the community and infection control team. © Athens Medical Society.

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