Changing in epidemiology of bacterial infections in cirrhosis-The role of drug-resistant bacteria
Iliana Mani, Larisa Vasilieva, Αlexandra Αlexopoulou, 2nd Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, “Hippokration” General Hospital Athens, Greece
Infections are common in cirrhotic patients, leading to worsening of liver function, episodes of acute decompensation and increased mortality. The high incidence of infections compared to the general population is the result of lack of local and systematic defense mechanisms combined with the phenomenon of bacterial translocation. Responsible pathogens are usually derived from endogenous flora, causing infections like spontaneous bacterial peritonitis and spontaneous bacteremia. Even though infections in cirrhotics have traditionally been induced by Gram-negative bacteria, changes in epidemiology have occurred such as increase in infections with grampositive cocci and rapid spread of multidrug-resistant strains. The frequency of multidrugresistant bacteria varies according to the geographical area. Moreover, the degree of resistance is not always the same. Consequently, the efficacy of empirical antimicrobial treatment has been reduced.
In these cases, successful treatment is dependent on the isolation of the responsible pathogen and the determination of its resistance to antibiotics. Since half of cultures of cirrhotic patients are negative, empirical administration of antibiotics could not be abandoned. Emergence of multidrug-resistant microbes should imply review of treatment strategy, surveillance of infections, registration of colonization in each center, knowledge of the microbial resistance pattern and measures to reduce it.
Key words: bacterial infections, cirrhosis, multidrug-resistant pathogens
Skin infections of humans and dogs caused by Malassezia yeasts: A review of the literature
Vasileios Stavropoulos, George Filioussis, Laboratory of Microbiology and Infectious Diseases,Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
Malassezia yeasts are the only eukaryotic commensal microorganisms of the normal skin of humans and animals. Their potential as causative agents in the pathogenesis of skin disorders causes continued speculation. The genus comprises 14 species, 8 of which have been linked to several skin diseases preferentially distributed in the seborrheic areas of the skin surface. The question whether they are mere commensals coincidentally found in diseased skin or a real cause of human skin disorders remains controversial. Malassezia furfuris the main anthropophilic species that is believed to be the causative agent of various human dermatological disorders including pityriasis versicolor, seborrheic dermatitis, atopic dermatitis, and dandruff. Predisposing factors to M. furfurskin diseases include bad nutrition, prolonged use of glucocorticoids or antibiotics. M. pachydermatisis a highly lipophilic species isolated from the skin and the external ear canal of healthy dogs. Humid environment, natural skin folding, sebaceous hypersecretion and prolonged use of glucocorticoids and / or antibiotics are factors that promote the growth of this species. Common clinical findings of M. pachydermatisdog infection are pruritic lesions characterized by alopecia, seborrhea, erythema and rancid smell. M. pachydermatis is occasionally isolated from human skin Moreover studies in which dogs have been infected by anthropophilic species of Malasseziaare also mentioned and contribute to the knowledge of ecology and possible mechanism of zoonotic transmission of this organism.
Key words: Malassezia spp., skin infections, human, dog
Emergence, prevalence and mechanisms of fluoroquinolone resistance in Neisseria gonorrhoeae: A literature review
Konstantinos Stefanakis, Maria Stefanaki, Kalliopi Theodoridou, Constantinos Tsiamis, Georgia Vrioni Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
Gonorrhea is a widespread sexually transmitted infection and a major community health concern. Medication against Neisseria gonorrhoeaehas been circulating for decades, but the bacteria have progressively become resistant to nearly all drugs administered against them. N. gonorrhoeaedeveloped resistance to sulfonamides, penicillin, tetracyclines and spectinomycin, in a chronological order, throughout the 20th century. Fluoroquinolones, notably ciprofloxacin, displayed exceptional potency against the bacteria. They debuted in the 1980s, and consumption peaked during the 1990s. However, this trend was hindered by the sporadic emergence of quinolone-resistant N. gonorrhoeae(QRNG) that thrived in the East Asia – Western Pacific region. The ever-increasing prevalence of quinolone resistance led to the drugs’ gradual exclusion from gonorrhea treatment guidelines around the globe. Fluoroquinolones directly interfere with DNA synthesis by inhibiting DNA gyrase and topoisomerase IV. The GyrA and ParC genes, which encode the homonymous structural subunits of these enzymes, are the main targets of mutations that yield quinolone resistance. Moreover, changes in the permeability of the bacterial cytoplasmic membrane, owing to the increase of efflux pumps, prevent the drug from reaching its target. The thorough examination of these procedures may uncover the mechanisms of antimicrobial resistance and bolster the development of new therapeutic choices against gonococcus, whereas the epidemiological study of the prevalence of QRNG is vital for public health. Azithromycin and third-generation cephalosporins are the current recommended antimicrobials issued against the disease. Nevertheless, recent findings and warnings issued by the WHO have shown that N. gonorrhoeae might involving into a superbug.
Key words: gonorrhea, Neisseria gonorrhoeae, quinolones, resistance, QRNG
In vitroactivity of ceftaroline against methicillin-resistant Staphylococcus aureusisolates from blood and complicated skin and soft tissue infections and update on the EUCAST breakpoints
Angeliki Pantazatou1, Olga Apostolou1, Ioannis Deliolanis1, Georgios Maropoulos1, Athanassios Priftis2, Athanassios Tsakris2, Joseph Papaparaskevas2
1.Department of Microbiology, “Laikon” General Hospital, 11527, Athens, Greece
2.Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 11527, Athens, Greece
Ceftaroline fosamil is a novel cephalosporin active against methicillin-resistant Staphylococcus aureus(MRSA) and multidrug-resistant Streptococcus pneumoniae(MDRSpn). The aim of the present study was the evaluation of the compound against MRSA isolates from blood and complicated skin and skin structure infections (CSSSIs), the comparison of the current CLSI and EUCAST MIC interpretation guidelines, the evaluation of the disk-diffusion method for susceptibility testing,and the investigation of the underlying mechanisms in borderline and/or resistant isolates. A total of 329 MRSA isolates were included in the study. Ceftaroline MIC range was 0.064 – 4 mg/L. MIC50 and MIC90 were 0.5 and 1 mg/L, respectively. Three isolates exhibited MIC = 4 mg/L, and were considered as resistant using the CLSI guidelines M100 28th Ed., whilst 15 more isolates exhibited MIC = 2 mg/L and were considered as intermediate. All these 18 isolates were categorized as resistant using the EUCAST guidelines v7.1, but using the updated EUCAST guidelines v8.0, the categorization fell in accordance with the CLSI ones. Disk diffusion (DD), according to EUCAST v7.1, resulted in very major errors at 0.3%, and major errors at 5.2% (among isolates exhibiting MIC = 1 mg/L); using the updated guidelines v8.0 the major errors rate decreased to 1.5%, but were replaced by minor errors at 3.0% rate. SCCmec typing revealed mainly the Ν146Κ, Ε150Κ and H351N substitutions. Ceftaroline has an excellent in vitroactivity against MRSA isolates from blood and/or CSSSI. The updated EUCAST guidelines amended the discrepancies that were detected regarding the categorization of isolates exhibiting MIC = 2 mg/L and the DD major errors.
Key words: Ceftaroline, Staphylococcus aureus, Minimum Inhibitory Concentration, EUCAST, CLSI
Prevalence and biofilm forming potency of multi-drug resistant Staphylococcus aureusamong food handlers in Arba Minch University, South Ethiopia.
Mohammedaman Mama1, Getaneh Alemu1, Aseer Manilal1, Mohammed Seid2, Akbar Idhayadhulla3
1.Department of Medical Laboratory Science, College of Medicine and Health Sciences, Arba Minch University, Arba Minch, Ethiopia
2.Department of Medical Laboratory Science, Arba Minch College of Health Sciences, Arba Minch, Ethiopia
3.Post Graduate and Research Department of Chemistry, Nehru Memorial College, (A?liated to Bharathidasan University), Puthanampatti -621007, Tamil Nadu, South India
Food borne diseases create pervasive health problems across the globe. The problem is severe in underdeveloped countries due to the difficulties in securing optimal hygienic food handling practices. Hence, this study is intended to explicate the prevalence, antibiotic resistance and biofilm forming profile of Staphylococcus aureusamong food handler’s working in Arba Minch University, South Ethiopia. A cross sectional study was conducted from April to June, 2015. Pre-tested structured questionnaire was used to collect data about socio demographic characteristics and other associated factors. The nasal samples were collected and examined for bacterial identification based on standard procedures. Bacterial isolates with highest and broadest rank of antimicrobial resistance and biofilm forming potency was chosen for partial 16s rRNA gene sequencing. All the laboratory experiments were performed in triplicates. A total of 281 food handlers were enrolled in the study with a response rate of 100%. Majority of the food handlers were females (72.6%) and were educated up to primary level (36.4%). Twenty (7.1 %) of them were found to be positive for nasal colonization of S. aureus, of which one strain (5.2%) was resistant to oxacillin. All the isolates showed high frequency of resistance to penicillin and cotrimoxazole. Results of biofilm forming assay revealed that out of 15 multidrug resistant isolates, two of them are potent biofilm producers. Further, DNA sequencing and BLAST analysis of the amplified ribosomal genes of two potent biofilm producers demonstrated a 98-99% homology with S. aureus16S rRNA genes. In conclusion, food handlers are usually the main source of food contamination with S. aureus. Therefore, constant epidemiological surveillance through biannual routine tests and improvement of personal hygiene are recommended to control the transmission route.
Key words: Food handlers, Staphylococcus aureus, nasal carriage, biofilm, multi-drug resistance
Role of hypoxia-inducible factor (HIF)-1α and CD11b in pathogenesis of experimental cerebral malaria in mice.
Kresna Septiandy Runtuk1, Loeki Enggar Fitri2, Rintis Noviyanti3
1.Master Program of Biomedical Sciences, Faculty of Medicine, Universitas Brawijaya, Malang, Indonesia
2.Parasitology Department, Faculty of Medicine, Universitas Brawijaya, Malang, Indonesia
3.Malaria Pathogenesis Unit, Eijkman Institute of Molecular Biology, Jakarta, Indonesia
Malaria is one of transmittable diseases caused by Plasmodiumspp. infection. Severe malaria, including cerebral malaria can lead to deaths. Involvement of cytokines and other molecular markers have been shown in development of cerebral malaria signs. The aims of the present study is to determine the effect of Plasmodium berghei ANKA to the HIF-1α and CD11b expressions, and the correlation between HIF-1α CD11b with cerebral malaria symptoms in mice model. C57BL/6 mice were divided into two groups, control group and group that was infected by Plasmodium berghei ANKA. Parasitemia and clinical score were observed until 7th day, then brains were collected and stained by immunohistochemistry to determine HIF-1α and CD11b expression in both groups. The HIF-1α and CD11b expressions were observed under 1000x magnification in light microscope. There was a significant differences between each group (p=0.001) of HIF-1α expression in response to Plasmodium berghei ANKA infection. In contrast, there were no differences on CD11b expression in response to Plasmodium berghei ANKA infection (p=0.096). There was no correlation between the expression of HIF-1α and CD11b (r=0.220) in mice with cerebral malaria. In conclusion, Plasmodium berghei ANKA infection enhanced HIF-1α expression but not CD11b due to the variability of microglia in the brain.
Key words: CD11b; Cerebral Malaria; HIF-1α; Malaria; Plasmodium berghei ANKA