Volume 24, Issue 3, 2016
Review
Latent tuberculosis infection (LTBI): a real host defence or a permanent threat?
Sanduzzi Alessandro,
Ponticiello Antonio,
Bocchino Marialuisa,
Perna Francesco,
Vatrella Alessandro
Screening of latent infection by Mycobacterium tuberculosis (LTBI) and treatment of positive subjects is the key point in the prevention of TB; such a strategy should be performed mainly among individuals with risk of progression. Progression from LTBI to active TB is highest both in recent contacts of patients with active TB, and in immunocompromised subjects. Therefore, LTBI could either be considered a permanent host defence or, seen from the opposite point of view, it could represent a long-lasting threat if the efficiency of the immune system declines over a lifetime. Interferon gamma release assays (IGRAs) show better sensitivity and specificity than the Mantoux test.
Innovations in the field of fungal biofilms: looking for new targets and new chemical compounds
Furlanetto Costanza,
Merluzzi Sonia,
Palcic Stefano
Biofilms pose a serious problem for public health. Penetration of pharmacological agents within a biofilm is hampered by the morphological structure of such microbial communities. A biofilm infection therefore entails adverse outcomes both in the field of cost management and patient prognosis. The problem is further complicated if the drugs available to combat a biofilm-related fungal infection versus a bacterial one are compared: in the case of a fungal infection, the drugs available are less efficacious than antibiotics used to counteract a bacterial infection. Furthermore, even the fairly recent introduction of antifungals, such as echinocandins, start presenting some limits of usage, such as ineffectiveness in treating some fungal populations and increased resistance. It therefore becomes imperative to search for innovative molecules in order to combat this condition. The discovery of new molecules and/or new targets can make a difference. This paper illustrates the main innovative molecules that are coming to light in the field of infection by fungal biofilms.
Original article
Antimicrobial susceptibility against penicillin, ampicillin and vancomycin of viridans group Streptococcus in oral microbiota of patients at risk of infective endocarditis
Süzük Serap,
Kaşkatepe Banu,
Çetin Mustafa
The viridans group Streptococci (VGS) are most abundant in the mouth; in some instances they might emerge as pathogens particularly in infective endocarditis (IE). In this study, we aimed to define and determine the susceptibility against antibiotics of VGS that are members of the oral microbiota of patients exhibiting a risk of developing IE. Forty-nine patients at risk of infective endocarditis were included in the study. Identification of the bacteria was performed using API STREP (bioMérieux, France). Gradient test strips (E-Test, France) were used to determine MIC of the bacteria against penicillin, ampicillin, and vancomycin. The distribution of the isolated VGS groups was determined as follows: Streptococcus mitis 32.6% and anginosus group - 32.6%, S. sanguinis group - 16.3%, S. mutans group - 12.2%, and S. salivarius group - 6.1%. The rates of resistance and reduced sensitivity of the isolates for penicillin and ampicillin were determined at 61.2% and 55.1%, respectively. However, all isolates were found to be susceptible to vancomycin. We conclude that the antimicrobial resistance of VGS should be determined on a regular basis locally, and decisions on therapeutic and prophylactic interventions should be given taking this resistance into consideration.
Report of data on children with non-typhi Salmonella gastroenteritis in a three-year period
Küçük Öznur ,
Biçer Suat,
Uğraş Meltem,
Çöl Defne,
Giray Tuba,
Çiler Erdağ Gülay ,
Gürol Yeşim,
Yılmaz Gülden,
Yalvaç Zerrin,
Vitrinel Ayça,
Kaspar Çiğdem
The purpose of this study was to evaluate the clinical and laboratory data of children with acute gastroenteritis caused by non-typhoid Salmonella spp. infections. Clinical (demographic data, symptoms and findings) and laboratory data (stool microscopy, rapid antigen tests, culture, multiplex polymerase chain reaction and blood test results) of children with acute gastroenteritis caused by non-typhoid Salmonella spp. between January 2010 and October 2012 were evaluated. Differences between the groups for categorical variables were estimated with a chi-square or Fisher exact test; for continuous variables with two independent samples a t test was used. P values < 0.05 were considered statistically significant.
Sixty-seven children, 39 (58.2%) males and 28 (41.8%) females aged between 1 - 16 years (mean ± SD: 4.64 ± 2.91), were diagnosed with acute bacterial gastroenteritis caused by non-typhoid Salmonella spp. The main serotypes are Salmonella enteritidis (85%) and Salmonella typhimurium (7.5%). The presenting symptoms were diarrhoea (95.5%), fever (61.1%), vomiting (34.3%), abdominal pain (32.8%), loss of appetite (7.4%) and malaise (7.4%). Fever and dehydration (moderate and/or severe) were detected in 11 (16.4%) patients. The mean leukocyte count was 10.930/μL [95% confidence interval (CI), SD: ± 5.710/μL], neutrophil count was 7.880/μL (95% CI, SD: ± 4.960/μL), CRP was 64.16 mg/L (95% CI, SD: ± 76.24 mg/L), and erythrocyte sedimentation rate was 34.72 mm/hour (95% CI, SD: ± 13.64 mm/h). Stool microscopy was positive for leukocytes in 18 patients (26.8%). The definitive diagnosis was made with positive stool culture (n = 65) and/or PCR test (n = 4). Viral antigen positivity was detected in 10 patients (14.9%), evaluated as viral co-infection and false positive results. Antibiotic therapy and hospitalization were required in 26 (38.8%) and 23 (34.3%) patients, respectively. Salmonella carriage was detected in one patient (1.5%). Bloody diarrhoea, leukocytes in stool with an increased erythrocyte sedimentation rate and a CRP level without overt leukocytosis may indicate Salmonella infection. Viral antigens may cause false positive results in fast antigen tests in cases where clinical and laboratory findings indicate bacterial aetiology. Stool culture is a reference method in diagnosis whereas some agents may be detected via molecular techniques (polymerase chain reaction) in spite of negative culture. Multiplex polymerase chain reaction may be used to detect Salmonella spp. and may reveal false positivity for viruses as well as the detection of other bacteria.
Risk factors for methicillin-resistant Staphylococcus aureus colonisation or infection in intensive care units and their reliability for predicting MRSA on ICU admission
Callejo-Torre Fernando,
Eiros Bouza Jose Maria,
Olaechea Astigarraga Pedro,
Coma Del Corral Maria Jesus,
Martínez Mercedes Palomar,
Alvarez-Lerma Francisco,
López-Pueyo Maria Jesús,
Study Group and ENVIN–HELICS
Predicting methicillin-resistant Staphylococcus aureus (MRSA) in intensive care units (ICUs) avoids inappropriate antimicrobial empirical treatment and enhances infection control. We describe risk factors for colonisation/infection related to MRSA (MRSA-C/I) in critically ill patients once in the ICU and on ICU admission, and search for an easy-to-use predictive model for MRSA colonisation/infection on ICU admission. This multicentre cohort study included 69,894 patients admitted consecutively (stay>24h) in April-June in the five-year period 2006-2010 from 147 Spanish ICUs participating in the National Surveillance Study of Nosocomial Infections in ICUs (ENVIN-HELICS). Data from all patients included were used to identify risk factors for MRSA-C/I during ICU stays, from admission to discharge, using uni- and multivariable analysis (Poisson regression) to check that the sample to be used to develop the predictive models was representative of standard critical care population. To identify risk factors for MRSA-C/I on ICU admission and to develop prediction models, multivariable logistic regression analysis were then performed only on those admitted in 2010 (n=16950, 2/3 for analysis and 1/3 for subsequent validation).
We found that, in the period 2006-2010, 1046 patients were MRSA-C/I. Independent risk factors for MRSA-C/I in ICU were: age>65, trauma or medical patient, high APACHE-II score, admitted from a long-term care facility, urinary catheter, previous antibiotic treatment and skin-soft tissue or post-surgical superficial skin infections. Colonisation with several different MDRs significantly increased the risk of MRSA-C/I. Risk factors on ICU admission were: male gender, trauma critical patient, urgent surgery, admitted from other ICUs, hospital ward or long-term facility, immunosuppression and skin-soft tissue infection. Although the best model to identify carriers of MRSA had a good discrimination (AUC-ROC, 0.77; 95%CI, 0.72-0.82), sensitivity was 67% and specificity 76.5%. Including more complex variables did not improve prediction capability. Our conclusion is that clinical-demographic risk factors for colonisation/infection related to MRSA should not be used to accurately identify patients who would benefit from empirical anti-MRSA treatment or from specific preventive measures. Independent risk factors for MRSA colonisation/infection during ICU stay and on ICU admission are described. The latter should be considered in future studies for MRSA prediction.
Streptococcus agalactiae: prevalence of antimicrobial resistance in vaginal and rectal swabs in Italian pregnant women
Matani Chiara,
Trezzi Michele,
Matteini Alice,
Catalani Carlotta,
Messeri Daniela,
Catalani Corrado
Intrapartum antibiotic prophylaxis (IAP) reduces both the vertical transmission of Streptococcus agalactiae or Group B Streptococcus (GBS) and the early onset of neonatal sepsis. However, existing guidelines do not recommend that antimicrobial susceptibility testing (AST) be routinely performed. Penicillin or ampicillin are indicated as first-choice antibiotics, cefazolin being an alternative in the case of history of mild allergic reactions, and vancomycin or clindamycin an alternative in the event of severe reactions. We performed a cross-sectional analysis to identify the presence of any bacterial resistance towards the antibiotics most frequently used for IAP in pregnant women with GBS positive vaginal-rectal swabs, in the Pistoia area of central Italy. Of the 255 tested samples, 65 (25.5%) were positive for GBS. Sensitivity to glycopeptides was over 90%, but lower to ampicillin and penicillin (87.10% and 87.93% respectively). Resistance towards clindamycin and erythromycin was as high as 43.75% and 32.20%. All tested GBS proved susceptible to moxifloxacin, linezolid and tigecycline. Our observed prevalence is aligned or slightly higher than data reported in other series. The less than full effectiveness and low percentages of ampicillin and penicillin sensitivity observed give cause for concern. We confirmed the increase in clindamycin and erythromycin resistance. Glycopeptides can be used as second-line antibiotics, but the complete AST of GBS should always be performed before IAP. Given that gentamicin is used synergically with penicillin when treating chorioamnionitis, it needs to be always included in the AST. This is the first study on the GBS sensitivity profile in Tuscany. Further investigation on a larger scale is required prior to implementing any changes in the current guidelines.
Identification of aminoglycoside resistance genes by Triplex PCR in Enterococcus spp. isolated from ICUs
Mirnejad Reza,
Sajjadi Nikta,
Zavaryani Sara Masoumi,
Piranfar Vahhab,
Hajihosseini Maryam,
Roshanfekr Maliheh
Early detection of antibiotic-resistant enterococci is an important part of patient treatment. Therefore, the aim of the present study was to evaluate the resistance patterns and simultaneously identify and characterise the resistance genes in Enterococcus spp. using a triplex polymerase chain reaction (PCR) method. In all, 150 consecutive Enterococcus spp were collected from several hospitals in Tehran (Iran) from January to December 2015. The Enterococcus species were identified by standard phenotypic/biochemical tests and PCR. The antimicrobial resistance patterns were determined using a disk diffusion method. The triplex PCR method was designed to identify gentamicin and other aminoglycoside resistance genes. Among the 150 Enterococcus specimens, 87 cases (58%) were Enterococcus faecalis, and 63 cases (42%) were Enterococcus faecium. The highest frequency of resistance was observed for tetracycline while the lowest was found for vancomycin. Among the identified samples, 56.9% contained the aac(6')-Ie-aph(2'')-Ia gene, 22.2% contained the aph(3')-IIIa gene, and 38.8% contained the ant(4')-Іa gene. Eight percent of the isolates contained the three aminoglycoside resistance genes. Data analysis showed that there was a significant correlation between the phenotypic gentamicin resistance and the presence of the aminoglycoside resistance genes (18.9%, p <0.05), while the correlation between the phenotypic streptomycin resistance and the corresponding genes was not significant (2.8%, p ≥0.5). Nearly half of the identified Enterococcus strains had increased aminoglycoside resistance. The direct correlation between resistance genes, such as the aminoglycoside resistance factor, and phenotypic resistance was not significant (p > 0.05).
Case report
A family cluster of hepatitis A virus due to an uncommon IA strain circulating in Campania (southern Italy), not associated with raw shellfish or berries: a wake-up call to implement vaccination against hepatitis A?
Tosone Grazia,
Mascolo Silvia,
Bruni Roberto,
Taffon Stefania,
Equestre Michele,
Tosti Maria Elena,
Ciccaglione Anna Rita,
Martucci Fiorella,
Liberti Alfonso,
Iannece Maria Donata,
Orlando Raffaele
Hepatitis A virus is a widely occurring disease, with different prevalence rates between countries in the North and West and those in the South and East. In Italy endemicity is low/medium, but not homogeneously distributed: in the northern/central regions a large hepatitis A outbreak due to genotype IA, related to the consumption of contaminated mixed frozen berries, occurred between 2013 and 2014, whereas in southern Italian regions recurrent outbreaks of hepatitis A, due to the IB genotype, still result from consumption of raw seafood. In 2014 an uncommon genotype IA strain was isolated from five patients (2 adults and 3 children) with hepatitis A, living in the surroundings of Naples (Campania) who did not have any of the most common risk factors for hepatitis A in Italy, such as consumption of raw shellfish or frozen berries, or travel to endemic countries. Moreover, based on the analysis of viral sequences obtained, this strain differed from several others in the national database, which had been recently isolated during Italian outbreaks. This case report reinforces the need to implement both information campaigns about the prevention of hepatitis A and vaccination programmes in childhood; in addition, it would be suitable to sequence strains routinely not only during large outbreaks of hepatitis A in order to obtain a more detailed national database of HAV strains circulating in Italy.
Atypical clinical presentation of meningococcal meningitis: a case report
Izzo Ilaria,
Pileri Paola,
Merello Maria,
Gnesin Paolo,
Cogi Enrico,
Aggiusti Carlo,
Giacomelli Laura,
Ettori Stefano,
Colombini Paolo,
Collidà Andrea
A young woman was examined in the Emergency Department for fever, pharyngitis and widespread petechial rash. Physical examination, including neurological evaluation, did not show any other abnormalities. Chest X-ray was negative. Blood exams showed leukocytosis and CPR 20 mg/dL (nv<0.5 mg/dL). On the basis of these results and petechial rash evidence, lumbar puncture was performed. CSF was opalescent; physico-chemical examination showed: total proteins 2.8 (nv 0.15-0.45), glucose 5 (nv 59-80), WBC 7600/µL (nv 0-4/ µL). In the hypothesis of meningococcal meningitis, antimicrobial therapy was started. Blood and cerebrospinal fluid cultures were positive for N. meningitidis. During the first hours the patient experienced hallucinations and mild psychomotor agitation, making a spontaneous recovery. A brain MRI showed minimal extra-axial inflammatory exudates. She was discharged after 10 days in good condition. We underline the need to consider meningococcal meningitis diagnosis when any suggestive symptom or sign is present, even in the absence of the classic meningitis triad, to obtain earlier diagnosis and an improved prognosis.
Postnatal cytomegalovirus infection in an infant with congenital thrombocytopenia: how it can support or mislead the diagnosis of Wiskott-Aldrich syndrome
Poddighe Dimitri,
Comi Elena Virginia,
Nedbal Marco,
Soresina Annarosa,
Bruni Paola
A male newborn developed a post-natal cytomegalovirus (CMV) infection, arising in the clinical setting of congenital thrombocytopenia, which was diagnosed as being alloimmune. The evidence of active CMV infection in an infant showing slow-resolution lower airways infection, persistent neonatal and low platelet volume thrombocytopenia, and diffuse eczema (associated to very high levels of serum immunoglobulin E) led to the diagnosis of Wiskott-Aldrich syndrome (WAS) before the third month of life, despite the presence of several confounding clinical factors. The correct interpretation of all clinical features supported the precocious diagnosis of WAS.
Recurrent complicated urinary tract infection due to rare pathogen Sphingomonas paucimobilis: contamination or real deal?
Demir Tulin,
Dadali Mumtaz
Sphingomonas paucimobilis is an aerobic, oxidase-positive, yellow-pigmented, non-fermentative, Gram-negative opportunistic pathogen that rarely causes infections
in humans. It is commonly found in nosocomial environments and, despite its low clinical virulence, it can be responsible for several different infections especially
among patients with underlying disease. Here we describe a clinical case of a 46-year-old male paraplegic patient with a history of neurogenic bladder due to insulin-dependent diabetes mellitus and renal failure who was admitted to the urology clinic of a university hospital in Kirsehir, Turkey, with the complaints of urinary tract infection (UTI) including fever, chills, dysuria, abdominal and back pain. The urine culture was positive for Sphingomonas paucimobilis identified by the Vitek-2 system and the patient was successfully treated with oral co-trimoxazole 800/160 mg twice a day for ten days associated to cefixime and fosfomycin.
A literature review of UTIs associated to Sphingomonas paucimobilis is reported as well.
HIV positive patient with HSV-2 encephalitis: case report
Pagliano Pasquale,
Ascione Tiziana,
Carleo Maria Aurora,
Boccia Giovanni,
De Caro Francesco,
Tortora Fabio
Incidence of brain infections in Human Immunodeficiency Virus (HIV) positive patients is reduced after the availability of current high active antiretroviral therapy (HAART). Herpes Simplex Virus type 2 (HSV-2) is an infrequent cause of encephalitis in HIV patients despite it is frequently involved in sexual transmitted infections. Here, we report a case of HSV-2 encephalitis occurring in a patient without full suppression of HIV replication within the brain.
A 38 year-old HIV infected man was admitted to our department because of recurrent generalized seizure and fever during the previous 24 hours. Eight months before our observation the patient was switched from a protease inhibitor based regimen to a rilpivirine-based regimen without any evidence of HIV-RNA replication in the plasma.
When the patient was admitted in our hospital, he was febrile and moderately confused, no deficit of cranial nerves was reported, motility was conserved, but he was unable to walk. Laboratory examinations performed at admission demonstrated an increase of cerebrospinal fluid (CSF) protein and cells with lymphocyte prevalence, and normal CSF glucose. HSV-2-DNA and HIV-RNA were present within CSF at admission. Nuclear Magnetic Resonance imaging of the brain revealed lesions of the medial part of both temporal lobes including hippocampus without any sign of bleeding. A 21-day course of acyclovir therapy was administered with consistent improvement of clinical findings and disappearance of HSV-2-DNA within CSF. After the episode, HAART was switched to a regimen with high CSF penetrability containing abacavir, lamivudine, darunavir and ritonavir. Twelve months after HSV-2 encephalitis neurologic evaluation was normal, but symptoms of depression were reported, HIV-RNA remained undetectable both in the plasma and CSF, and CD4+ lymphocytes were above 500/L. No opportunistic infection was reported.
Patients switched to regimen well tolerated such those containing rilpivirine, that have poor drug concentration within CSF could be considered at risk for opportunistic infection of the brain. Further larger investigation needs to confirm this finding.
The Infections in the History of Medicine
Zika virus infection: Challenge
Wiwanitkit Viroj
Not available
Daniel Mollière (1848-1890), the French anatomist and surgeon, and his encounters with nosocomial infections in the operating theatre
Tsoucalas Gregory,
Laios Konstantinos,
Karamanou Marianna,
Sgantzos Markos,
Androutsos George
Daniel Mollière, was a French anatomist and surgeon, born in Lyon, who succeeded in his short life in making his mark in surgery. He was a prolific writer who left a series of medical treatises and a committed surgeon who was responsible for various significant innovative apparatuses in the medical sper. As he lived in an era when the role of microbe had already been recognized, he was among the first to use antisepsis and install extreme measures against microbes, both in the air and on the skin'. Fountains with fresh clean water, carbonic acid, cross ventilation, medical blouses, combined with Valette's apparatus for the dressing of amputations, were some of his precautions to reduce surgical infections and post-operative mortality.
