Home About us Contact
|
Home About us Contact | ||
|
|
||
Polymicrobial Infection (polymicrobial + infection)
Selected AbstractsIncidence, spectrum and antibiotic sensitivity pattern of bacterial infections among patients with acute pancreatitisJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2001Pramod Kumar Garg Abstract Background and Aim: Secondary infection of pancreatic necrotic tissue and peripancreatic fluid is a serious complication of acute pancreatitis resulting in significant morbidity and mortality. The aim of this study was to find out the spectrum of bacterial infections, and their antibiotic sensitivity pattern in patients with acute pancreatitis. Methods: All consecutive patients with acute pancreatitis were studied prospectively. Detailed investigations were carried out to identify bacterial infections and their antibiotic sensitivities in patients with suspected infection. These investigations included cultures of various body fluids, throat swabs, indwelling cannula and catheter tips. Pancreatic tissue was obtained by using needle aspiration or at surgery for Gram's stain, culture and sensitivity. All cultures were repeated until the presence of infection was confirmed or excluded. Results: A total of 169 patients with acute pancreatitis were studied during the period between January 1997 and June 2000 (mean age 41.3 years; 116 males and 53 females). Of the 169 patients, 63 had infections at various sites. A total of 80 cultures were positive, and 12 different bacterial isolates were cultured from samples taken from these 63 patients. Polymicrobial infection was seen in 32% of patients. Twenty-four patients had a confirmed pancreatic infection. Blood cultures had a growth of organisms in 19 patients, with evidence of ongoing or worsening pancreatitis, thus raising a strong suspicion of infected necrosis in them. The commonest organisms were Escherichia coli from 20 cultures and Pseudomonas aeruginosa from 18 cultures. The antibiotic sensitivity pattern showed that most bacteria were sensitive to third generation cephalosporins and quinolones; notably among them were cefotaxime, ceftazidime, and ciprofloxacin. Conclusion: Bacterial infections were seen in 37% of patients with acute pancreatitis. The commonest organisms were Pseudomonas aeruginosa and Escherichia coli. Most bacterial isolates were sensitive to third generation cephalosporins and quinolones. [source] Polymicrobial lung infection in postrenal transplant recipient diagnosed by fine-needle aspiration cytologyDIAGNOSTIC CYTOPATHOLOGY, Issue 4 2010Rajan Duggal M.D. Abstract Tuberculous and fungal infections are among the non-neoplastic lesions of the lung, in which fine-needle aspiration cytology (FNAC) has proven to be a useful technique in both immunocompromised and immunocompetent patients. The presence of polymicrobial infection in a renal transplant recipient is documented in the literature, but has rarely been diagnosed on cytology. We report a case of concomitant pulmonary cryptococcosis, aspergillosis, and tuberculosis in a renal transplant recipient diagnosed on FNAC. A 50-year-old renal transplant recipient, asymptomatic for 3 year, presented with intermittent low-grade fever associated with cough, expectoration, and a newly developed cavitatory lesion in the left lung on chest X-ray. Computed tomography-guided FNAC performed on the lung lesion showed fungal profiles with septate hyphae and acute-angled branching consistent with morphology of Aspergillus. In addition, numerous yeast forms of cryptococcus and a few acid-fast mycobacterial tubercle bacilli were seen. Guided FNAC is a useful and reliable technique for the diagnosis of pulmonary infection. One should always keep in mind the possibility of polymicrobial infections especially inimmunocompromised patients. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source] Significance of bacterial identification by molecular biology methodsENDODONTIC TOPICS, Issue 1 2004David A. Spratt Rapid advances in molecular biology over the last 20 years have provided a bewildering array of techniques aimed at helping us to tease apart all aspects of biology. The discipline of microbiology has gained greatly from these advances especially with respect to detection and identification of micro-organisms. Indeed these molecular biology techniques have changed the way we classy all life on Earth. An important part of endodontic microbiology is detection and identification of the micro-organisms associated with initiation and progression of this polymicrobial infection. A range of appropriate molecular techniques are reviewed in the present article and include aspects of comparative 16S rRNA gene sequencing, polymerase chain reaction detection, strategies for identification of unculturable bacteria, and whole community analysis. Some of these techniques are widely used in endodontic microbiology while others are used by only a few workers. The advantages and disadvantages of all the techniques are discussed and put into perspective. [source] Microbial interactions and differential protein expression in Staphylococcus aureus ,Candida albicans dual-species biofilmsFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2010Brian M. Peters Abstract The fungal species Candida albicans and the bacterial species Staphylococcus aureus are responsible for a majority of hospital-acquired infections and often coinfect critically ill patients as complicating polymicrobial biofilms. To investigate biofilm structure during polymicrobial growth, dual-species biofilms were imaged with confocal scanning laser microscopy. Analyses revealed a unique biofilm architecture where S. aureus commonly associated with the hyphal elements of C. albicans. This physical interaction may provide staphylococci with an invasion strategy because candidal hyphae can penetrate through epithelial layers. To further understand the molecular mechanisms possibly responsible for previously demonstrated amplified virulence during coinfection, protein expression studies were undertaken. Differential in-gel electrophoresis identified a total of 27 proteins to be significantly differentially produced by these organisms during coculture biofilm growth. Among the upregulated staphylococcal proteins was l -lactate dehydrogenase 1, which confers resistance to host-derived oxidative stressors. Among the downregulated proteins was the global transcriptional repressor of virulence factors, CodY. These findings demonstrate that the hyphae-mediated enhanced pathogenesis of S. aureus may not only be due to physical interactions but can also be attributed to the differential regulation of specific virulence factors induced during polymicrobial growth. Further characterization of the intricate interaction between these pathogens at the molecular level is warranted, as it may aid in the design of novel therapeutic strategies aimed at combating fungal,bacterial polymicrobial infection. [source] Protective role of osteopontin in endodontic infectionIMMUNOLOGY, Issue 1 2010Susan R. Rittling Summary Endodontic infections are polymicrobial infections resulting in bone destruction and tooth loss. The host response to these infections is complex, including both innate and adaptive mechanisms. Osteopontin (OPN), a secreted, integrin-binding protein, functions in the regulation of immune responses and enhancement of leucocyte migration. We have assessed the role of OPN in the host response to endodontic infection using a well-characterized mouse model. Periapical bone loss associated with endodontic infection was significantly more severe in OPN-deficient mice compared with wild-type 3 weeks after infection, and was associated with increased areas of inflammation. Expression of cytokines associated with bone loss, interleukin-1, (IL-1,) and RANKL, was increased 3 days after infection. There was little effect of OPN deficiency on the adaptive immune response to these infections, as there was no effect of genotype on the ratio of bacteria-specific immunoglobulin G1 and G2a in the serum of infected mice. Furthermore, there was no difference in the expression of cytokines associated with T helper type 1/type2 balance: IL-12, IL-10 and interferon-,. In infected tissues, neutrophil infiltration into the lesion area was slightly increased in OPN-deficient animals 3 days after infection: this was confirmed by a significant increase in expression of neutrophil elastase in OPN-deficient samples at this time-point. We conclude that OPN has a protective effect on polymicrobial infection, at least partially because of alterations in phagocyte recruitment and/or persistence at the sites of infection, and that this molecule has a potential therapeutic role in polymicrobial infections. [source] Cryptococcal infection in sarcoidosisINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 11 2002Khosrow Mehrany MD A 48-year-old man with a history of sarcoidosis was transferred to the Mayo Clinic for evaluation and management of progressive neurologic decline. Two years before admission, he was admitted to a local hospital with mental status changes accompanied by ataxia and severe headache. A diagnosis of pulmonary and central nervous system sarcoidosis was made based on computed tomography of the head, lumbar puncture, and chest radiography. A mediastinoscopy with lymph node biopsy exhibited noncaseating granulomas and negative stains for microorganisms. Prednisone therapy was initiated at 80 mg/day. Clinical improvement was apparent for 13 months during steroid therapy until the slow taper reached a dosage of 20 mg/day. At that time, the patient was readmitted to the local hospital with severe confusion and skin lesions. When intravenous methylprednisolone therapy for presumed central nervous system sarcoidosis did not improve the patient's mental status, he was transferred to the Mayo Clinic. Physical examination of the thighs revealed large, well-marginated, indurated, irregularly bordered, violaceous plaques and rare, umbilicated, satellite papules with central hemorrhagic crusts (Fig. 1A). Superficially ulcerated plaques with a similar appearance to the thigh lesions were coalescing around the lower legs (Fig. 1B). A skin biopsy specimen of the thigh demonstrated abundant numbers of encapsulated organisms and minimal inflammatory response (Fig. 2). Skin, blood, and cerebrospinal fluid cultures confirmed the presence of Cryptococcus neoformans. Amphotericin and flucytosine combination therapy was initiated, and steroid dosages were gradually tapered. A test for human immunodeficiency virus was negative. The patient was dismissed from hospital after a complicated 2-month course resulting in improved mental status but progression of the lower extremity ulcerations as a result of polymicrobial infection. Figure 1. (A) Violaceous plaque with satellite papules on thigh. (B) Ulcerating plaques coalescing around leg Figure 2. (A) Sparse inflammatory infiltrate and abundant encapsulated organisms (hematoxylin and eosin; × 20). (B) Cryptococcal organisms (Gomori's methenamine silver; × 40) [source] Prophylaxis of posttraumatic endophthalmitisACTA OPHTHALMOLOGICA, Issue 2009A ABU EL ASRAR Infectious endophthalmitis is a devastating complication of open globe injuries. The incidence of culture-positive endophthalmitis after open globe injuries varies between 0.5% and 17%. Several reports have demonstrated that delayed primary repair, dirty wound, breach of lens capsule, retained intraocular foreign body (IOFB), grade 4 injury (presenting visual acuity of worse than 5/200 to light perception), placement of primary intraocular lens, and rural setting are associated with an increased risk of posttraumatic endophthalmitis. Posttraumatic endophthalmitis is associated with its own microbiologic spectrum which is distinct from other subgroups of exogenous endophthalmitis. Posttraumatic endophthalmitis still carries a poor prognosis. Reasons for guarded prognosis include polymicrobial infection and the virulence of the infecting microorganisms. In addition, concomitant injuries may directly result in ocular damage that limits ultimate visual recovery. Because of the substantial incidence of endophthalmitis after open globe injuries, careful consideration should be given to the use of prophylactic antimicrobial therapy. The purpose of prophylaxis is to provide effective antibiotic levels as rapidly as possible against a broad range of organisms. Good coverage for most organisms is obtained with intravenous vancomycin coupled with a third generation cephalosporin, such as ceftazidime, which can penetrate the vitreous cavity in effective levels in inflamed aphakic experimental eyes. Recently, the use of prophylactic intravitreal antibiotic administration in high-risk cases was recommended. [source] | ||||||||||