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1.  Mycotic Abdominal Aneurysm Caused by Campylobacter Fetus: A Case Report for Surgical Management 
Annals of Vascular Diseases  2011;4(1):56-59.
We report a rare case of mycotic abdominal aortic aneurysm associated with Campylobacter fetus. A 72-year-old male admitted to the hospital because of pain in the right lower quadrant with pyrexia. The enhanced abdominal computed tomography (CT) examination showed abdominal aortic aneurysm (AAA) measuring 50 mm in maximum diameter and a high-density area of soft tissue density from the right lateral wall to the anterior wall of the aorta. However, since the patient showed no significant signs of defervescence after antibiotics administration, so we performed emergency surgery on the patient based on the diagnosis of impending rupture of mycotic AAA. The aneurysm was resected in situ reconstruction using a bifurcated albumin-coated knitted Dacron graft was performed. The cultures of blood and aneurysmal wall grew Campylobacter fetus, allowing early diagnosis and appropriate surgical management in this case, and the patient is making satisfactory progress. This is the fifth report of mycotic AAA characterizing culture positive for Campylobacter fetus in blood and tissue culture of the aortic aneurysm wall.
PMCID: PMC3595778  PMID: 23555431
mycotic abdominal aneurysm; Campylobacter fetus; vascular surgery
2.  Detection of extended-spectrum beta-lactamases in members of the family Enterobacteriaceae: comparison of the double-disk and three-dimensional tests. 
The three-dimensional and clavulanate double-disk potentiation tests were compared as procedures for the detection of extended-spectrum beta-lactamase production in 32 strains of Escherichia coli and Klebsiella pneumoniae, 31 of which produced TEM-1, TEM-2, TEM-3, TEM-4, TEM-5, TEM-7, TEM-8, TEM-9, TEM-10, TEM-12, TEM-101, SHV-1, SHV-2, SHV-3, SHV-4, SHV-5, CAZ-2, MIR-1, or an unidentified extended-spectrum beta-lactamase with a pI of 5.95, with some strains producing multiple beta-lactamases. The three-dimensional test, which was performed in conjunction with a routine disk diffusion test, detected extended-spectrum beta-lactamase production in 26 of 28 (93%) of the strains that produced extended-spectrum beta-lactamases. The clavulanate double-disk potentiation test detected extended-spectrum beta-lactamases in only 22 of the 28 strains (79%) when it was performed as currently recommended. The three-dimensional test, when performed in conjunction with the disk diffusion test, offered the advantages of providing simultaneous information about both antibiotic susceptibility and extended-spectrum beta-lactamase production, coupled with a greater sensitivity and earlier detection of extended-spectrum beta-lactamases.
PMCID: PMC192203  PMID: 1416878
3.  Clipping of a Mycotic Basilar Trunk Aneurysm under Cardiac Arrest in a Pregnant AIDS Patient 
Skull Base  2010;20(6):459-463.
We present the first case of a coccidioidomycosis mycotic anterior inferior cerebellar artery (AICA) aneurysm that was clipped under hypothermic cardiac standstill in a pregnant acquired immunodeficiency syndrome (AIDS) patient. A 24-year-old pregnant AIDS patient presented with intraventricular hemorrhage and hydrocephalus. Angiography revealed an 8-mm basilar trunk aneurysm with the right AICA protruding from the side wall of the aneurysm. The patient underwent a retrosigmoid craniotomy and direct clipping of the aneurysm under hypothermic cardiac standstill. At presentation, the patient had a poor grade due to subarachnoid and intraventricular hemorrhage. Despite her large posterior circulation aneurysm in the setting of AIDS with extensive coccidioidomycosis meningitis, the lesion was clipped successfully. To do so required the full range of neurosurgical repertoire, including a skull base approach and hypothermic cardiac standstill.
PMCID: PMC3134816  PMID: 21772805
Coccidioidomycosis meningitis; hypothermic cardiac standstill; mycotic aneurysm
4.  Imported PER-1 producing Pseudomonas aeruginosa, PER-1 producing Acinetobacter baumanii and VIM-2-producing Pseudomonas aeruginosa strains in Hungary 
Pseudomonas aeruginosa and Acinetobacter baumanii are important nosocomial pathogens with wide intrinsic resistance. However, due to the dissemination of the acquired resistance mechanisms, such as extended-spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL) production, multidrug resistant strains have been isolated more often.
Case presentation
We report a case of a Hungarian tourist, who was initially hospitalized in Egypt and later transferred to Hungary. On the day of admission PER-1-producing P. aeruginosa, PER-1 producing A. baumannii, SHV-5-producing Klebsiella pneumoniae and VIM-2-producing P. aeruginosa isolates were subcultured from the patient's samples in Hungary. Comparing the pulsed-field gel electrophoresis (PFGE) patterns of the P. aeruginosa strains from the patient to the P. aeruginosa strains occurring in this hospital, we can state that the PER-1-producing P. aeruginosa and VIM-2-producing P. aeruginosa had external origin.
This is the first report of PER-1-producing P. aeruginosa,and PER-1-producing A. baumanii strains in Hungary. This case highlights the importance of spreading of the beta-lactamase-mediated resistance mechanisms between countries and continents, showing the importance of careful screening and the isolation of patients arriving from a different country.
PMCID: PMC2430584  PMID: 18513394
5.  Molecular Analysis of the Simultaneous Production of Two SHV-Type Extended-Spectrum Beta-Lactamases in a Clinical Isolate of Enterobacter cloacae by Using Single-Nucleotide Polymorphism Genotyping 
Antimicrobial Agents and Chemotherapy  2005;49(11):4716-4720.
Bacteria that simultaneously produce multiple extended-spectrum beta-lactamases are frequently isolated. We report an Enterobacter cloacae isolate, ES24, producing four different beta-lactamases (AmpC type beta-lactamase, TEM-1, SHV-7, and a novel extended-spectrum beta-lactamase, SHV-30). Direct sequencing of blaSHV gene products gave a “double peak” at position 703, suggesting the presence of more than one allele. Using fluorescence resonance energy transfer real-time PCR to detect single-nucleotide polymorphisms, we were able to distinguish two different blaSHV genes in a single isolate. This may prove to be a useful technique in surveys of beta-lactamase production in contemporary clinical isolates.
PMCID: PMC1280125  PMID: 16251316
6.  Nosocomial Escherichia coli meningitis in adults: Report of four cases and literature review 
We report four cases of nosocomial E. coli meningitis, in male patients with accidental and neurosurgical trauma. The interval between accidents/neurosurgical procedures and the onset of meningitis was 2-15 days (mean 6.25 days). The most consistent clinical features were fever and deterioration of consciousness level. Emergence of extended spectrum beta lactamase E. coli strains had been observed in two (50%) of our cases and the mean duration of antimicrobial treatment was 16.5 days (range: 6-24 days). Two of the four patients (50%) died in the hospital.
PMCID: PMC3821438  PMID: 24250185
E. coli; neurosurgical procedure; nosocomial meningitis
7.  E. coli Meningitis Presenting in a Patient with Disseminated Strongyloides stercoralis 
Introduction. Spontaneous Escherichia coli meningitis is an infrequent condition in adults and is associated with some predisposing factors, including severe Strongyloides stercoralis (SS) infections. Case Presentation. A 43-year-old Hispanic man, with history of travelling to the jungle regions of Peru and Brazil two decades ago, and who received prednisone due to Bell's palsy for three weeks before admission, presented to the Emergency Department with diarrhea, fever, and hematochezia. A week after admission he developed drowsiness, meningeal signs, abdominal distension, and constipation. A cerebrospinal fluid culture showed extended spectrum β-lactamase producing E. coli. A colonoscopy was performed and showed pancolitis. Three days after the procedure the patient became unstable and developed peritoneal signs. He underwent a laparotomy, which ended up in a total colectomy and partial proctectomy due to toxic megacolon. Three days later the patient died in the intensive care unit due to septic shock. Autopsy was performed and microscopic examination revealed the presence of multiple Strongyloides larvae throughout the body. Conclusion. Strongyloides stercoralis infection should be excluded in adults with spontaneous E. coli meningitis, especially, if gastrointestinal symptoms and history of travelling to an endemic area are present. Even with a proper diagnosis and management, disseminated strongyloidiasis has a poor prognosis.
PMCID: PMC3845250  PMID: 24324900
8.  Aortoesophageal Fistula after Endovascular Aortic Aneurysm Repair of a Mycotic Thoracic Aneurysm 
Mycotic aneurysms constitute a small proportion of aortic aneurysms. Endovascular repair of mycotic aneurysms has been applied with good short-term and midterm results. However, the uncommon aortoenteric fistula formation remains a potentially fatal complication when repairing such infective aneurysms. We present the case of an 80-year-old woman with thoracic and abdominal aortic mycotic aneurysms, which were successfully treated with endografting. However, the patient presented 3 months later with upper gastrointestinal bleeding secondary to erosion of the thoracic graft into the oesophagus. The patient was treated conservatively due to the high risk of surgical repair. There is currently little exposure to the management of mycotic aortic aneurysms. If suspected, imaging of the entire vasculature will aid initial diagnosis and highlight the extent of the disease process, allowing for efficient management. Aortic endografting for mycotic thoracic aneurysms is a high-risk procedure yet is still an appropriate intervention. Aortoenteric fistulae pose a rare but severe complication of aortic endografting in this setting.
PMCID: PMC3167181  PMID: 21904681
9.  Aorto-enteric fistula development secondary to mycotic abdominal aortic aneurysm following intravesical bacillus Calmette–Guerin (BCG) treatment for transitional cell carcinoma of the bladder 
Intravesical BCG-instillation for bladder cancer is considered safe but is not without risk. While most side-effects are localised and self-limiting, the development of secondary vascular pathology is a rare but significant complication.
A 77-year-old male presented with a mycotic abdominal aortic aneurysm and associated aorto-enteric fistula 18 months after receiving intravesical BCG-instillations for early stage transitional cell carcinoma.
Response rates to intravesical BCG for early stage transitional cell carcinoma are high. The procedure produces a localised inflammatory response in the bladder but the exact mechanism of action is unclear. The treatment is generally well tolerated but BCG-sepsis and secondary vascular complications have been documented.
Mycotic abdominal aortic aneurysm with associated aorto-enteric fistula secondary to BCG is very rare. Few examples have been documented internationally and the extent of corresponding research and associated management proposals is limited.
Surgical options include in situ repair with prosthetic graft, debridement with extra-anatomical bypass and, occasionally, endovascular stent grafting. Recommended medical therapy for systemic BCG infection is Isoniazid, Rifampicin and Ethambutol.
Current screening methods must be updated with clarification regarding duration of anti-tuberculous therapy and impact of concomitant anti-tuberculous medication on the therapeutic action of intravesical BCG. Long-term outcomes for patients post graft repair for mycotic aneurysm are unknown and more research is required regarding the susceptibility of vascular grafts to mycobacterial infection.
Recognition of the risks associated with BCG-instillations, even in immunocompetent subjects, is paramount and must be considered even several months or years after receiving the therapy.
PMCID: PMC3537938  PMID: 23127864
BCG; Aortic aneurysm; Aorto-enteric fistula; Bladder carcinoma
10.  Infective endocarditis with cerebrovascular complications: timing of surgical intervention 
Management of infective endocarditis (IE) with cerebrovascular complications is difficult due to absence of concrete evidence. These patients usually have multiple neurological deficits and the optimal timing for cardiac operation remains controversial. The aims of this study were to present cases and discuss the treatment options for IE with cerebrovascular complications. From 1998 to 2010, 51 patients underwent operations for IE at our institution. From a review of medical records, 10 patients (19.6%) with preoperative neurological complications were identified. Data on these 10 patients were analysed. Cerebrovascular complications included cerebral infarction (n = 4, 40.0%), mycotic aneurysm (n = 1, 10.0%), mycotic aneurysm plus cerebral infarction (n = 3, 30.0%), meningitis (n = 1, 10.0%) and mycotic aneurysm with cerebral haemorrhage plus meningitis (n = 1, 10.0%). Of 5 patients having mycotic aneurysms, 3 underwent clipping before cardiac operations. The mean interval from craniotomy to cardiac operations was 26.7 ± 21.8 days. A cardiac operation was performed initially on seven patients. The mean interval from the onset of neurological deficit to cardiac operation was 7.4 ± 9.8 days. The mortality rate was 10.0%. Postoperative deterioration was not observed. Management of IE with cerebrovascular complications should be based on case-by-case multidisciplinary assessment of potential risks and benefits of intracranial and cardiac operations.
PMCID: PMC3420269  PMID: 22108940
Infective endocarditis; Cerebrovascular complications; Surgical intervention
11.  Extended-Spectrum Beta-Lactamases Producing Escherichia coli and Klebsiella pneumoniae: A Multi-Centric Study Across Karnataka 
There are sporadic reports on detection of extended-spectrum beta-lactamases (ESBL) producers from Karnataka; hence, this is a first multicentric study across Karnataka state to determine the prevalence of ESBL production among clinical isolates of Escherichia coli and Klebsiella pneumoniae.
Aims and objectives:
To determine the prevalence of ESBL producing clinical isolates of E. coli and K. pneumoniae from five geographically distributed centers across Karnataka, to study the susceptibility of ESBL producing isolates to other beta-lactam and beta-lactam-beta-lactamase inhibitors and to demonstrate transferability of plasmids coding for ESBL phenotype.
Materials and Methods:
Two hundred isolates of E. coli and K. pneumoniae each were collected from each of the five centers (Bellary, Dharwad, Davangere, Kolar and Mangalore). They were screened for resistance to screening agents (ceftazidime, cefotaxime, ceftriaxone, aztreonam) and positive isolates were confirmed for ESBL production by test described by Clinical and Laboratory Standards Institute. Co-production of ESBL and AmpC beta-lactamase was identified by using amino-phenylboronic acid disk method. Susceptibility of ESBL producers to beta-lactam antibiotics and beta-lactamase inhibitors was performed. Transferability of plasmids was performed by conjugation experiment.
Overall prevalence of ESBL production among E. coli and K. pneumoniae across five centers of the state was 57.5%. ESBL production was found to be 61.4% among E. coli and 46.2% among K. pneumoniae. ESBL production was significantly more among E. coli than K. pneumoniae. Significant variations in distribution of ESBL across the state was observed among E. coli isolates, but not among K. pneumoniae isolates. All ESBL producers demonstrated minimum inhibitory concentration levels ≥2 μg/ml towards cefotaxime, ceftazidime and ceftriaxone.
Overall prevalence of ESBL production among clinical isolates of E. coli and K. pneumoniae across Karnataka state was high. The prevalence of ESBL production was significantly higher with E. coli than K. pneumoniae isolates. Higher rates of resistance to ceftriaxone and cefotaxime than to ceftazidime suggests the possibility of presence of CTX-M type ESBLs. Of all the beta-lactam/beta-lactamase inhibitor combinations tested, cefepime-tazobactam demonstrated highest in-vitro activity against ESBL producers. There was no statistical difference in the transferability of plasmids among E. coli and K. pneumoniae.
PMCID: PMC3969652
Beta-lactamase; beta-lactamase inhibitor; extended-spectrum beta-lactamases
12.  Meningitis Caused by Escherichia coli Producing TEM-52 Extended-Spectrum β-Lactamase within an Extensive Outbreak in a Neonatal Ward: Epidemiological Investigation and Characterization of the Strain▿  
Journal of Clinical Microbiology  2010;48(7):2459-2463.
Outbreaks caused by Enterobacteriaceae isolates producing extended-spectrum β-lactamases (ESBL) in neonatal wards can be difficult to control. We report here an extensive outbreak in a neonatal ward with a case of meningitis caused by an ESBL-producing Escherichia coli strain. Between 24 March and 29 April 2009, among the 59 neonates present in the ward, 26 neonates with ESBL-producing E. coli rectal colonization were detected (44%). One of the colonized neonates developed meningitis with a favorable outcome after treatment combining imipenem, gentamicin, and ciprofloxacin. Despite strict intensification of hygiene and isolation procedures for more than 1 month, ward closure to new admissions was necessary to control the outbreak. Randomly amplified polymorphic DNA and pulsed-field gel electrophoresis analysis performed on 31 isolates recovered from 26 neonates and two mother's milk samples showed a clonal strain. ESBL PCR assays indicated that the strain harbored a TEM-52 ESBL encoded by an IncI1 replicon. Phylogenetic analysis by multilocus sequence typing showed that the strain belonged to rare phylogenetic group C, which is closely related to group B1 but appears as group A by the triplex PCR phylogrouping method. The strain harbored the virulence genes fuyA, aer, and iroN and was virulent in a mouse model of septicemia. This work indicates the high potential of colonization, transmission, and virulence of some ESBL-producing E. coli clones.
PMCID: PMC2897521  PMID: 20519482
13.  Multi-resistant Escherichia coli and mycotic aneurysm: two case reports 
Mycotic aneurysms account for a small proportion of all aneurysms. Escherichia coli a gram-negative organism, is recognised as a rare cause of aortic aneurysm. We report two cases of mycotic aneurysm caused by the same strain of multi-resistant Escherichia coli. The purpose of this case report is to highlight the possibility that this strain may be associated with an increased risk of endovascular infection especially in extra-aortic sites. These aneurysms can be difficult to detect and can have serious consequences.
Case presentation
In case one, the patient presented with symptoms and signs of septicaemia secondary to a urinary tract infection. Despite adequate treatment the patient continued with pyrexia and raised inflammatory markers, therefore a series of CT scans of the abdomen and thorax were performed, which revealed two intra-thoracic pseudo-aneurysms with associated haematomas. In case two, the patient also developed Escherichia coli septicaemia. On day 44 he developed a swelling on the right side of his neck. An ultrasound scan showed a pseudoaneurysm of the right common carotid artery.
Whilst a case report cannot prove that a heightened risk exists, we suggest that it is an area worthy of further surveillance. We recommend when older patients with atheromatosis develop prolonged Escherichia coli septicaemia, the possibility of an infected aneurysm should be borne in mind.
PMCID: PMC2726478  PMID: 19830106
14.  Burden of different beta-lactamase classes among clinical isolates of AmpC-producing Pseudomonas aeruginosa in burn patients: A prospective study 
Pseudomonas aeruginosa is one of the most common pathogens causing infections in burns, and shows increasing resistance to β-lactam antibiotics by producing different classes of beta-lactamases. It is also not unusual to find a single isolate that expresses multiple β-lactamase enzymes, further complicating the treatment options. Thus, in this study, we aimed to determine the coexistence of different beta-lactamase enzymes in clinical isolates of P. aeruginosa in the burn ward.
Materials and Methods:
A total of 101 clinical isolates of P. aeruginosa from the burn ward were identified and tested for the presence of different beta-lactamase enzymes (extended spectrum beta lactamase (ESBL), Amp C and metallo β-lactamases (MBL) from October 2006 to May 2009. In vitro susceptibility pattern of antipseudomonal antibiotics was done by the Kirby Bauer disc diffusion method.
A total of 33 (32.7%) isolates were confirmed to be positive for AmpC beta-lactamase. Co-production of AmpC along with ESBL and MBL was reported in 24.5% and 45.5% isolates, respectively. A total of 12 (11.9%) isolates were resistant to three or more antibiotic classes (multidrug resistance). Imipenem and piperacillin/tazobactum showed high sensitivity, with 86.1% and 82.2%, respectively.
This study reveals the high prevalence of multidrug- resistant P. aeruginosa producing beta-lactamase enzymes of different mechanisms in this region from burn patients. The emerging antimicrobial resistance in burn wound pathogens poses serious therapeutic challenge. Thus proper antibiotic policy and measures to restrict the indiscriminate use of cephalosporins and carbapenems should be taken to minimize the emergence of this multiple beta -lactamase producing pathogen.
PMCID: PMC3506070  PMID: 23188953
AmpC; extended-spectrum beta lactamase; metallo β-lactamases; Pseudomonas aeruginosa
15.  Spontaneous disruption of mycotic aneurysm involving innominate artery. 
Journal of Korean Medical Science  2003;18(4):589-591.
We report a case of ruptured mycotic aneurysm involving innominate artery requiring an urgent surgical treatment. A 62-yr-old woman presented with fever and dyspnea. Previously, she was diagnosed with colon cancer and received right hemicolectomy and one cycle of adjuvant chemotherapy. On echocardiogram, pericardial effusion was noted and emergency pericardiocentesis was performed. CT scan revealed aortic aneurysm involving ascending aorta and innominate artery, and thrombi surrounding those structures. Patch repair of the defect in the ascending aorta and ringed Goretex graft to bypass the innominate and ascending aorta were performed. We believe that this is the first case of ruptured mycotic aneurysm involving innominate artery.
PMCID: PMC3055067  PMID: 12923339
Current opinion in pharmacology  2007;7(5):459-469.
Summary of recent advances
Since their first description more than twenty years ago, Escherichia coli and Klebsiella pneumoniae possessing extended-spectrum class A beta-lactamases (ESBLs) continue to thwart our best clinical efforts. In the “early years” the most common beta-lactamases were of the TEM and SHV varieties. Now, CTX-M enzymes are being discovered though out the world and are becoming the most prevalent beta-lactamases found in clinical isolates. The Klebsiella pneumoniae carbapenemases (KPC) (ESBL type enzymes that confer resistance to extended spectrum cephalosporins and carbapenems) present the most significant challenge to date. Structural studies of ESBLs indicate that active site expansion and remodeling are responsible for this extended hydrolytic activity. Continuing questions still exist regarding the optimal detection method for ESBLs. Most relevant are the increasing concerns regarding the status of carbapenems as “best therapy” for ESBL producing bacteria in light of the emergence of carbapenemases.
PMCID: PMC2235939  PMID: 17875405
17.  What is the optimal timing for surgery in infective endocarditis with cerebrovascular complications? 
Neurologic dysfunction complicates the course of 10–40% of left-side infective endocarditis (IE). In right-sided IE, instead, when systemic emboli occur, paradoxical embolism should be considered. The spectrum of neurologic events includes embolic cerebrovascular complication (CVC), intracranial haemorrhage, ruptured mycotic aneurysm, transient ischaemic attack (TIA), meningitis, encephalopathy and brain abscess. Cardiopulmonary bypass might exacerbate neurological deficits due to: heparinization and secondary cerebral haemorrhage; hypotension and cerebral oedema in areas of the disrupted blood brain barrier. A best evidence topic was written according to a structured protocol. The question addressed was, whether there is an optimal timing for surgery in IE with CVCs. One hundred papers were found using the reported search criteria, and out of these 20 papers, provided the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results were tabulated. We found that evidence is conflicting because of lack of controlled studies. The optimal timing for the valve replacement depends on the type of neurological complication and the urgency of the operation. The new 2009 Guidelines on the prevention, diagnosis, and treatment of infective endocarditis (IE) recommend a multidisciplinary approach and to wait for 1–2 weeks of antibiotics treatment before performing cardiac surgery. However, early surgery is indicated in: heart failure (class 1 B), uncontrolled infection (class 1 B) and prevention of embolic events (class 1B/C). After a stroke, surgery should not be delayed as long as coma is absent and cerebral haemorrhage has been excluded by cranial CT (class IIa level B). After a TIA or a silent cerebral embolism, surgery is recommended without delay (class 1 level B). In intracranial haemorrhage (ICH), surgery must be postponed for at least 1 month (class 1 level C). Surgery for prosthetic valve endocarditis (PVE) follows the general principles outlined for native valve IE. Every patient should have a repeated head CT scan immediately before the operation to rule out a preoperative haemorrhagic transformation of a brain infarction. The presence of a haematoma warrants neurosurgical consultation and consideration of cerebral angiography to rule out a mycotic aneurysm.
PMCID: PMC3420303  PMID: 22108925
Infective endocarditis; Cerebrovascular complication; Brain injury; Stroke cardiac surgery; Timing
18.  Ruptured Intracranial Mycotic Aneurysm in Infective Endocarditis: A Natural History 
Case Reports in Medicine  2010;2010:168408.
Mycotic aneurysms are a rare cause of intracranial aneurysms that develop in the presence of infections such as infective endocarditis. They account for a small percentage of all intracranial aneurysms and carry a high-mortality rate when ruptured. The authors report a case of a 54-year-old man who presented with infective endocarditis of the mitral valve and acute stroke. He subsequently developed subarachnoid hemorrhage during antibiotic treatment, and a large intracranial aneurysm was discovered on CT Angiography. His lesion quickly progressed into an intraparenchymal hemorrhage, requiring emergent craniotomy and aneurysm clipping. Current recommendations on the management of intracranial Mycotic Aneurysms are based on few retrospective case studies. The natural history of the patient's ruptured aneurysm is presented, as well as a literature review on the management and available treatment modalities.
PMCID: PMC2946581  PMID: 20885918
19.  A Conserved Virulence Plasmidic Region Contributes to the Virulence of the Multiresistant Escherichia coli Meningitis Strain S286 Belonging to Phylogenetic Group C 
PLoS ONE  2013;8(9):e74423.
Recent isolation of the non-K1 Escherichia coli neonatal meningitis strain S286, belonging to phylogroup C, which is closely related to major group B1, and producing an extended-spectrum beta-lactamase, encouraged us to seek the genetic determinants responsible for its virulence. We show that S286 belongs to the sequence O type ST23O78 and harbors 4 large plasmids. The largest one, pS286colV (∼120 kb), not related to resistance, contains genes characteristic of a Conserved Virulence Plasmidic (CVP) region initially identified in B2 extra-intestinal avian pathogenic E. coli (APEC) strains and in the B2 neonatal meningitis E. coli strain S88. The sequence of this CVP region has a strong homology (98%) with that of the recently sequenced plasmid pChi7122-1 of the O78 APEC strain Chi7122. A CVP plasmid-cured variant of S286 was less virulent than the wild type strain in a neonatal rat sepsis model with a significant lower level of bacteremia at 24 h (4.1±1.41 versus 2.60±0.16 log CFU/ml, p = 0.001) and mortality. However, the mortality in the model of adult mice was comparable between wild type and variant indicating that pS286colV is not sufficient by itself to fully explain the virulence of S286. Gene expression analysis of pS286colV in iron depleted environment was very close to that of pS88, suggesting that genes of CVP region may be expressed similarly in two very different genetic backgrounds (group C versus group B2). Screening a collection of 178 human A/B1 extraintestinal pathogenic E. coli (ExPEC) strains revealed that the CVP region is highly prevalent (23%) and MLST analysis indicated that these CVP positive strains belong to several clusters and mostly to phylogroup C. The virulence of S286 is explained in part by the presence of CVP region and this region has spread in different clusters of human A/B1 ExPEC, especially in group C.
PMCID: PMC3784414  PMID: 24086343
20.  Mycotic visceral aneurysm complicating infectious endocarditis: Imaging diagnosis and follow-up 
One of the rarest complications of endocarditis, infected (mycotic) aneurysms result from haematogenous dissemination of septic emboli and occur more frequently in patients with cardiac valvular abnormalities or prosthetic valves, intravenous drug abuse, diabetes and immunosuppression conditions such as HIV infection. Although often clinically unsuspected, mycotic aneurysms are potentially life-threatening because of disseminated sepsis and propensity to rupture. Contrast-enhanced multidetector CT provides prompt detection, characterization and vascular mapping of these lesions, allowing correct planning of surgical or interventional therapies and reproducible follow-up. Because of their characteristically unpredictable behaviour, mycotic aneurysms may undergo spontaneous thrombosis, size reduction, rapid enlargement or rupture, therefore strict imaging surveillance with CT and/or color Doppler ultrasound is necessary.
PMCID: PMC3391851  PMID: 22787357
Endocarditis; mesenteric artery; mycotic aneurysm; sepsis; visceral aneurysm
21.  Extended-Spectrum Beta-Lactamases Producing E. coli in Wildlife, yet Another Form of Environmental Pollution? 
Wildlife is normally not exposed to clinically used antimicrobial agents but can acquire antimicrobial resistant bacteria through contact with humans, domesticated animals and the environment, where water polluted with feces seems to be the most important vector. Escherichia coli, an ubiquitous commensal bacterial species colonizing the intestinal tract of mammals and birds, is also found in the environment. Extended-spectrum beta-lactamases producing E. coli (ESBL-E. coli) represent a major problem in human and veterinary medicine, particular in nosocomial infections. Additionally an onset of community-acquired ESBL-E. coli infections and an emergence in livestock farming has been observed in recent years, suggesting a successful transmission as well as persistence of ESBL-E. coli strains outside clinical settings. Another parallel worldwide phenomenon is the spread of ESBL-E. coli into the environment beyond human and domesticated animal populations, and this seems to be directly influenced by antibiotic practice. This might be a collateral consequence of the community-onset of ESBL-E. coli infections but can result (a) in a subsequent colonization of wild animal populations which can turn into an infectious source or even a reservoir of ESBL-E. coli, (b) in a contribution of wildlife to the spread and transmission of ESBL-E. coli into fragile environmental niches, (c) in new putative infection cycles between wildlife, domesticated animals and humans, and (d) in problems in the medical treatment of wildlife. This review aims to summarize the current knowledge on ESBL-E. coli in wildlife, in turn underlining the need for more large scale investigations, in particular sentinel studies to monitor the impact of multiresistant bacteria on wildlife.
PMCID: PMC3244693  PMID: 22203818
ESBL; wildlife; wild birds; rodents; multiresistance
22.  Different ratios of the piperacillin-tazobactam combination for treatment of experimental meningitis due to Klebsiella pneumoniae producing the TEM-3 extended-spectrum beta-lactamase. 
We evaluated the pharmacokinetics and therapeutic efficacies of piperacillin and tazobactam, a beta-lactamase inhibitor, given either alone or in different combinations (80:10, 200:10, and 80:25 mg/kg/h), in experimental meningitis due to a strain of Klebsiella pneumoniae producing the TEM-3 extended-spectrum beta-lactamase. Treatment was administered intravenously as a 7-h constant infusion preceded by a bolus of 20% of the total dose. The mean (+/- standard deviation) rates of penetration into the cerebrospinal fluid (CSF) of infected animals were 6.7 +/- 3.9% for piperacillin given alone and 36.3 +/- 21.9% for tazobactam given alone. Combination treatment significantly magnified the concentration of either drug in CSF. Concentrations of bacteria in CSF increased throughout therapy in animals given either drug alone, even at high dosages. In animals given the combination at dosages of 80:10 and 200/10 mg/kg/h, only a suboptimal reduction of CSF bacterial titers was obtained in vivo, i.e. -0.49 +/- 0.34 and -0.73 +/- 0.49 log CFU/ml/h, respectively. An increase in the tazobactam dosage within the combination (80:25 mg/kg/h) was required in order to obtain a significantly faster elimination of viable organisms from the CSF (-0.97 +/- 0.35 log CFU/ml/h). The study shows that tazobactam is able to provide effective protection against piperacillin hydrolysis by the TEM-3 enzyme within the CSF. Appropriate dosage regimens of various beta-lactam-tazobactam combinations may deserve comparative studies in experimental meningitis caused by organisms producing extended-spectrum beta-lactamases.
PMCID: PMC284425  PMID: 8192442
23.  Risk Factors Associated with the Community-Acquired Colonization of Extended-Spectrum Beta-Lactamase (ESBL) Positive Escherichia Coli. An Exploratory Case-Control Study 
PLoS ONE  2013;8(9):e74323.
The number of extended-spectrum beta-lactamase (ESBL) positive (+) Escherichia coli is increasing worldwide. In contrast with many other multidrug-resistant bacteria, it is suspected that they predominantly spread within the community. The objective of this study was to assess factors associated with community-acquired colonization of ESBL (+) E. coli.
We performed a matched case-control study at the Charité University Hospital Berlin between May 2011 and January 2012. Cases were defined as patients colonized with community-acquired ESBL (+) E. coli identified <72 h after hospital admission. Controls were patients that carried no ESBL-positive bacteria but an ESBL-negative E.coli identified <72 h after hospital admission. Two controls per case were chosen from potential controls according to admission date. Case and control patients completed a questionnaire assessing nutritional habits, travel habits, household situation and language most commonly spoken at home (mother tongue). An additional rectal swab was obtained together with the questionnaire to verify colonization status. Genotypes of ESBL (+) E. coli strains were determined by PCR and sequencing. Risk factors associated with ESBL (+) E. coli colonization were analyzed by a multivariable conditional logistic regression analysis.
We analyzed 85 cases and 170 controls, respectively. In the multivariable analysis, speaking an Asian language most commonly at home (OR = 13.4, CI 95% 3.3–53.8; p<0.001) and frequently eating pork (≥3 meals per week) showed to be independently associated with ESBL colonization (OR = 3.5, CI 95% 1.8–6.6; p<0.001). The most common ESBL genotypes were CTX-M-1 with 44% (n = 37), CTX-M-15 with 28% (n = 24) and CTX-M-14 with 13% (n = 11).
An Asian mother tongue and frequently consuming certain types of meat like pork can be independently associated with the colonization of ESBL-positive bacteria. We found neither frequent consumption of poultry nor previous use of antibiotics to be associated with ESBL colonization.
PMCID: PMC3770595  PMID: 24040229
24.  Increase resistant rates and ESBL production between E. coli isolates causing urinary tract infection in young patients from Iran 
Brazilian Journal of Microbiology  2012;43(2):766-769.
Emerging antimicrobial resistance rates and Extended-spectrum beta-lactamase producing Escherichia coli recovered from urinary tract infections (UTI) is an increasing problem in specific regions, limiting therapeutic options. One hundred E. coli isolates causing UTI in patients with age from 2 months to 12 years admitted at CMC in the period of April 2009 to March 2010 were tested for antibiotic susceptibility using the disk diffusion method. Surprisingly high resistance rates were recorded for E. coli against TMP/SMX (84%), cefalotin (66%), cefuroxime (50%), cefixime (50%) and ceftriaxone (45%). Antimicrobial susceptibility of E. coli isolates was followed by meropenem (98%), amikacin (95%), nitrofurantoin (91%) and gentamicin (68%). Extended spectrum beta-lactamase production, was observed in 32% of community and 42% of nosocomial isolates. The results of this study and numerous observations regarding the increasing resistance to these antibiotics, in several countries, emphasize the need for local population-specific surveillance for guiding empirical therapy for UTI in children.
PMCID: PMC3768812  PMID: 24031888
E. coli; Urinary Tract Infection; Antimicrobial susceptibility; ESBL
25.  Transradial approach for the endovascular treatment of type I endoleak after aortic aneurysm repair: a case report 
BMC Surgery  2013;13(Suppl 2):S47.
Endovascular repair of aortic aneurysms (EVAR) is obtained through the positioning of an aortic stent-graft, which excludes the aneurysmatic dilation. Type I endoleak is the most common complication, and it is caused by an incompetent proximal or distal attachment site, causing the separation between the stent-graft and the native arterial wall, and in turn creating direct communication between the aneurysm sac and the systemic arterial circulation. Endoleak occurrence is associated with high intrasac pressures, and requires a quick repair to prevent abdominal aortic aneurysm rupture.
Case presentation
We report the first case of a 80-year-old man undergoing percutaneous closure of a peri-graft endoleak (type I) by transcatheter embolization through radial arterial access.
The transradial approach has been shown to be a safe and effective alternative to the traditional transfemoral approach. A decrease in vascular complications and improved patient comfort are the primary benefits of this technique in patients with previous EVAR.
PMCID: PMC3851154  PMID: 24267381

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