Fabrizio Taglietti

Methicillin-Resistant Staphylococcus aureus: A Community Health Threat

Abstract Methicillin-resistant Staphylococcus aureus (MRSA), one of the most common causes of infections, has been traditionally recognized as a nosocomial pathogen. However, in recent years, its epidemiology has radically changed, being now observed even more frequently in the community, and accounting for > 50% of staphylococcal infections in the US outpatient setting. Community-acquired (CA)-MRSA strains typically cause infections among otherwise healthy individuals, with risk factors differing from those of nosocomial MRSA. The clinical manifestations may range from a furuncle to life-threatening infections, such as necrotizing fasciitis and pneumonia. The antibiotic treatment of these infections may also differ because CA-MRSA strains often retain susceptibility to antimicrobials other than glycopeptides and newer agents. Moreover, the production of toxins, such as the Panton-Valentine leukocidin (PVL), should influence the antibiotic choice because in these cases the use of a combination therapy with antimicrobial agents able to decrease toxin production is suggested. There are still many unanswered key questions regarding the epidemiology, prevention, and treatment of CA-MRSA infections. This article reviews current knowledge of CA-MRSA.

Reversion to susceptibility of a carbapenem-resistant clinical isolate of Klebsiella pneumoniae producing KPC-3

OBJECTIVES We report the case of a kidney-transplant patient, suffering an intra-abdominal abscess at the surgical site caused by a carbapenem-resistant ST258 Klebsiella pneumoniae clone, producing the KPC-3 carbapenemase. Under tigecycline treatment, the patient developed a sepsis caused by a carbapenem-susceptible ST258 K. pneumoniae strain. Complete DNA sequences of the plasmids carried by the resistant and susceptible strains from this patient were determined. METHODS The complete DNA sequences of plasmids were obtained by applying the 454 Genome Sequencer FLX-PLUS procedure on a library constructed of total plasmid DNA purified from the carbapenem-resistant and -susceptible strains. RESULTS In the carbapenem-resistant strain, four plasmids encoding 24 resistance genes, including blaKPC-3, and two putative virulence clusters were detected. In the susceptible strain, large rearrangements occurred in the KPC-carrying plasmid, causing the deletion of the entire Tn4401::blaKPC-3 transposon, with the consequent reversion of the strain to carbapenem susceptibility. The patient was successfully treated with carbapenems and fully recovered. CONCLUSIONS The description of the plasmid content in these two strains gives interesting insights into the plasticity of KPC-carrying plasmids in K. pneumoniae.

Cytomegalovirus pneumonia in immunocompetent host: Case report and literature review

CMV infection is highly prevalent in general population and its clinical picture generally ranges from asymptomatic disease to mononucleosis-like syndrome. While severe life-threatening CMV disease is well documented in certain immunocompromised risk groups, severe infection with symptomatic pneumonia in immunocompetent hosts has been rarely documented. In this paper we describe a case of primary CMV infection, complicated by severe CMV pneumonia in an immunocompetent host, successfully treated with oral valganciclovir. Moreover, we reviewed CMV pneumonia cases in immunocompetent adults reported in the literature.

Management of antibiotic resistance in the intensive care unit setting

Over the past few decades, an alarming increase of infections caused by antibiotic-resistant pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus species, carbapenem-resistant Pseudomonas aeruginosa, extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella spp., and multidrug-resistant Acinetobacter spp., has been observed, particularly in intensive care units. For clinicians, the rising resistance rate observed in nosocomial pathogens, when coupled with the lack of effective antimicrobials, represents the real challenge in the therapeutic management of critically ill patients. The contribution of clinicians in minimizing the increasing trend of resistance is represented by reduction of the patients’ exposure to antibiotics, which reduces the resistance-selecting pressure, and by avoiding unnecessary antibiotic treatments. Recent issues on strategies to minimize resistance development and to appropriately manage critically ill patients with infections caused by multidrug-resistant organisms in the intensive care unit setting are discussed in this article.

Carbapenemase-producing Klebsiella pneumoniae-related mortality among solid organ-transplanted patients: do we know enough?

F. Taglietti, S. Di Bella, V. Galati, S. Topino, M. Iappelli, N. Petrosillo Carbapenemase-producing Klebsiella pneumoniaerelated mortality among solid organ-transplanted patients: do we know enough? Transpl Infect Dis 2013: 15: E164–E165. All rights reserved F. Taglietti, S. Di Bella, V. Galati, S. Topino, M. Iappelli, N. Petrosillo National Institute for Infectious Diseases “L. Spallanzani,” Rome, Italy, Kidney Transplant Unit, San Camillo-Forlanini Hospital, Rome, Italy

Hemolytic anemia due to acute cytomegalovirus infection in an immunocompetent adult: a case report and review of the literature

IntroductionCytomegalovirus is a common virus responsible for a wide range of clinical manifestations. Hemolysis is a rare but potentially life-threatening complication of cytomegalovirus infection, described mostly in immunocompromised patients, the pathogenesis of which is still unclear.We performed a review of the literature regarding cases of hemolytic anemia during acute cytomegalovirus infection in apparently immunocompetent individuals. We searched for relevant articles in PubMed for the period of 1980 through 2008.Case presentationWe describe a case of Coombs-negative hemolytic anemia in a 44-year-old Caucasian immunocompetent man with acute cytomegalovirus infection.ConclusionClinicians should consider cytomegalovirus infection in the differential diagnosis of hemolytic anemia in immunocompetent adults. Possible therapeutic options include antiviral therapy and steroids, although the best treatment strategy is still controversial.

Clostridium difficile infection among hospitalized HIV-infected individuals: epidemiology and risk factors: results from a case-control study (2002-2013)

BackgroundHIV infection is a risk factor for Clostridium difficile infection (CDI) yet the immune deficiency predisposing to CDI is not well understood, despite an increasing incidence of CDI among such individuals. We aimed to estimate the incidence and to evaluate the risk factors of CDI among an HIV cohort in Italy.MethodsWe conducted a retrospective case-control (1:2) study. Clinical records of HIV inpatients admitted to the National Institute for Infectious Disease “L. Spallanzani”, Rome, were reviewed (2002-2013). Cases: HIV inpatients with HO-HCFA CDI, and controls: HIV inpatients without CDI, were matched by gender and age. Logistic regression was used to identify risk factors associated with CDI.ResultsWe found 79 CDI episodes (5.1 per 1000 HIV hospital admissions, 3.4 per 10000 HIV patient-days). The mean age of cases was 46 years. At univariate analysis factors associated with CDI included: antimycobacterial drug exposure, treatment for Pneumocystis pneumonia, acid suppressant exposure, previous hospitalization, antibiotic exposure, low CD4 cell count, high Charlson score, low creatinine, low albumin and low gammaglobulin level. Using multivariate analysis, lower gammaglobulin level and low serum albumin at admission were independently associated with CDI among HIV-infected patients.ConclusionsLow gammaglobulin and low albumin levels at admission are associated with an increased risk of developing CDI. A deficiency in humoral immunity appears to play a major role in the development of CDI. The potential protective role of albumin warrants further investigation.

Are There Reasons To Prefer Tetracyclines to Macrolides in Older Patients with Community-Acquired Pneumonia?

We thank S. Di Bella et al. for their comments regarding the potential of tetracyclines to improve the treatment of community-acquired pneumonia (CAP) in elderly patients at risk of Clostridium difficile infection (CDI) ([1][1]). Prescribing for CAP is a major driver of seasonal trends in antibiotic

Daptomycin efficacy in the central nervous system of a patient with disseminated methicillin- resistant Staphylococcus aureus infection: a case report

IntroductionStaphylococcus aureus has emerged as a major nosocomial pathogen in the last decades and also represents the second most common pathogen isolated from patients in outpatient settings. Although methicillin-resistant S.aureus infections were traditionally limited to hospitals, community-associated cases of methicillin-resistant S.aureus infections have been reported. In our case, we observed an unexpected event during treatment.Case presentationA 60-year-old Caucasian man developed fever and multiple muscle and brain abscesses caused by Panton-Valentine leukocidin-negative community-associated methicillin-resistant S. aureus.ConclusionAlthough our patient was given antimicrobials active against the isolated methicillin-resistant S. aureus strain, it was only after the introduction of daptomycin that his skin, soft tissue and muscle lesions and also brain manifestations improved.

Acute hepatocellular and cholestatic injury during therapy with hydrochlorothiazide - clinicohistopathologic findings: a case report.

IntroductionHydrochlorothiazide and thiazide-like diuretics are considered first-line drugs for initial therapy in uncomplicated arterial hypertension. Acute cholecystitis is a well-known complication during treatment with thiazide, and these drugs are also reported to be followed by pronounced insulin resistance.Case presentationWe describe a case of acute cholestatic hepatitis in a 68-year-old Caucasian man who was receiving olmesartan and hydrochlorothiazide for arterial hypertension. From the clinical and histologic findings, we diagnosed him as having hepatocellular-cholestatic injury and a disorder of glucose metabolism in the liver. To the best of our knowledge, no histopathologic description of hydrochlorothiazide hepatotoxicity has previously been documented in the literature.ConclusionIn the differential diagnosis of cholestatic hepatitis, clinicians should be aware of the possibility of liver damage in patients receiving hydrochlorothiazide therapy.