Global spread of carbapenemase-producing bacteria

Klinički značaj enzima karbapenemaza očituje se u njihovoj sposobnosti hidrolize karbapenema, zbog čega bakterije koje ih proizvode razvijaju otpornost na ovu podskupinu β-laktamskih antibiotika širokog spektra, kao i na većinu ostalih pripadnika iste skupine (penicilini, cefalosporini). Karbapenemaza producirajući sojevi gram-negativnih bakterija od velikog su epidemiološkog značaja, budući da trend širenja ovih β-laktamaza među bolničkim, ali i izvanbolničkim izolatima postaje ozbiljna globalna prijetnja. Često uzrokuju manje ili veće epidemije u zdravstvenim ustanovama. Geni koji kodiraju karbapenemaze obično se prenose na druge bakterije zajedno s genima koji su odgovorni za rezistenciju na ostale skupine antibiotika, kao što su kinoloni i aminoglikozidi. Među najproširenijim karbapenemazama nalaze se metalo-β-laktamaze IMP, VIM i NDM-tipa, a početkom trećeg milenija postali smo svjedoci globalne krize zbog eksplozivnog širenja višestruko otporne Klebsiella pneumoniae koja proizvodi KPC β-laktamazu. Zabrinjava činjenica da pojava i širenje enterobakterija, pseudomonasa i acinetobaktera otpornih na karbapeneme značajno pridonosi povećanom pobolu i smrtnosti pacijenata. Za probir karbapenemaza producirajućih sojeva u mikrobiološkom laboratoriju koriste se klasične fenotipske metode zasnovane na kultivaciji, nakon čega je neophodno potvrditi produkciju enzima primjenom potvrdnih (fenotipskih i/ili molekularnih) metoda. Identifikacija specifičnih gena koji kodiraju enzime temelji se na molekularnim tehnikama. Dijagnostiku i interpretaciju dobivenih laboratorijskih rezultata otežava neprepoznavanje rezistencije nižeg stupnja koja se može javiti u određenom postotku karbapenemaza producirajućih sojeva. Zbog vrlo ograničenog izbora djelotvornih antibiotika vrlo je značajno rano otkrivanje producirajućih sojeva te sprječavanje njihova prijenosa. Pravovremeno otkrivanje inficiranih pacijenata, ali i zdravih kliconoša ključan je korak u prevenciji širenja rezistentnih sojeva bakterija.Carbapenemases are clinically important enzymes because they hydrolyse and inactivate the broad-spectrum β-lactam antibiotics carbapenems. Carbapenemase-producing strains are resistant to carbapenems and to most of the other classes of β-lactams (penicillins, cephalosporins). The growing trend of the carbapenemase-producing strains between inpatient and outpatient isolates of gram-negative bacteria is becoming a global health threat. Infections caused by carbapenemase-producing strains often occur as outbreaks. In addition, carbapenemase- encoding genes are frequently transferred to other bacteria along with the genes responsible for resistance to other classes of antibiotics, such as quinolones and aminoglycosides. The most widespread carbapenemases are metallo-β-lactamase IMP, VIM and NDM-types. At the beginning of the third millennium we witnessed the global spread of KPC-producing, multidrugresistant Klebsiella pneumoniae. The emergence and spread of carbapenem-resistant Enterobacteriaceae, Pseudomonas and Acinetobacter strains leads to an increase in morbidity and mortality rates. Phenotypic methods based on cultivation are used for screening of carbapenemase- producing strains, however, enzyme production must be confirmed by phenotypic or molecular methods. Identification of specific carbapenemase-encoding genes is mainly based on molecular techniques. Low level resistance that can occur in a certain percentage of carbapenemase-producing strains complicates detection and laboratory tests interpretation. Due to the very limited choice of effective antibiotics early detection of carbapenemase-producing strains becomes of paramount importance. Strict infection control measures, including active surveillance for timely detection of colonised patients and prompt isolation of carriers are key steps for preventing the transmission of these bacteria in healthcare settings

The listeriosis triangle: Pathogen, host and the environment

Listeria monocytogenes is a foodborne pathogen well known for its adaptability to diverse environment and host niches and its high fatality rate among infected immunocompromised populations. Infection in the immunocompetent host occurs but risk factors for the disease primarily points to abnormalities in cell-mediated and innate immunity as major predispositions to listeriosis. After ingestion of contaminated food, this pathogen is able to cross the intestinal, blood-brain and placental barrier and leads to gastroenteritis, meningitis and maternofetal infections which may result in abortion and spontaneous stillbirth. Despite the extensive use of this bacterium in the study of cell-mediated immunity and intracellular growth, our understanding of the host, pathogen and environmental factors that impact the pathogenesis of listeriosis is still incomplete. This review will summarize current knowledge, including our own efforts, about pathogen, host and environmental factors that influence, and contribute to the pathogenesis of Listeria monocytogenes infection

Educiranost primalja o cijepljenju protiv gripe tijekom trudnoće

Gripa je potencijalno ozbiljna zarazna bolest, posebno za određene skupine kao što su trudnice, koje imaju povećani rizik od obolijevanja i smrtnosti. Osjetljivost trudnica na infekciju virusom gripe objašnjava se fiziološkim promjenama koje nastaju u trudnoći. Prevencija gripe cijepljenjem ključna je strategija za sprječavanje nastanka bolesti i razvoj mogućih komplikacija u trudnica i novorođenčadi. Primalje trebaju biti pouzdan i pravovremen izvor informacija o cijepljenju s obzirom na to da rade u izravnom doticaju s trudnicama. Cilj ovog istraživanja je ispitati znanje i stavove primalja u Hrvatskoj o cijepljenju trudnica protiv gripe. Rezultati anketnog istraživanja kojim su obuhvaćene 82 primalje iz cijele države pokazali su ograničena znanja ispitanika o cijepljenju protiv gripe tijekom trudnoće. Manje od polovine ispitanika smatra da je cijepljenje protiv gripe u trudnoći učinkovito, a samo četvrtina ispitanika smatra da je cjepivo sigurno. Trećina ispitanih primalja zna da se trudnicama u Hrvatskoj preporučuje inaktivirano cjepivo protiv gripe, a manje od četvrtine zna da se cjepivo može primijeniti u bilo kojem tromjesečju. Velika većina primalja uključenih u istraživanje (93%) navela je da ne pružaju trudnicama informacije o cijepljenju protiv gripe, a kao vodeći razlog navode manjak educiranosti. Nije utvrđena statistički značajna razlika u znanju i stavovima ovisno o stupnju obrazovanja i duljini radnog staža. Poboljšanje procijepljenosti trudnica protiv gripe uvelike ovisi o preporukama zdravstvenih djelatnika. Ova studija pruža vrijedan uvid u znanja, stavove i praksu hrvatskih primalja ukazujući na potrebu dodatne edukacije primalja o sigurnosti cjepiva protiv gripe i potencijalnoj koristi za majku i dijete

Systemic and Local CC Chemokines Production in a Murine Model of Listeria monocytogenes Infection

Repeated intragastric inoculation of Listeria monocytogenes into BALB/c mice resulted in prolonged bacteraemia and severe hepatic infection. Bacteria could also be isolated from the brain tissue of all experimental mice. During the inflammatory process, chemokine concentrations typically increased at the local site in comparison to the systemic level. The liver-to-serum ratio was more pronounced in the case of macrophage inflammatory protein 1α (MIP-1α), suggesting its role in the inflammatory response in the liver. The ratio of brain-to-serum concentration of monocyte chemoattractant protein 1 (MCP-1) remained the same as in the control animals, while it was lower in the infected mice, both in the case MIP-1α and in the case of regulated on activation, normal T cell expressed and secreted (RANTES). This is in correlation with slight inflammatory infiltrates found in the brain tissue early in infection

Izazovi određivanja antimikrobnog učinka polifenola

As multidrug resistance gains momentum, the last two decades have seen an ever-growing interest in the antimicrobial properties of plant extracts and plant-derived compounds. Most of the focus is on polyphenols – a large and diverse group of phytochemicals with strong antibacterial activity. Testing methods provide reliable results as long as they follow standard procedures. However, methods and procedures used in antimicrobial susceptibility testing (AST) are often too diverse to allow comparison of results. The lack of uniformity and comparability is much owed to the absence of guidelines. The focus of this review is to give a critical overview of different methods used in the assessment of polyphenols antimicrobial efficacy and to highlight the importance of their standardisation.Istraživanje antimikrobnih učinaka biljnih ekstrakata i spojeva u proteklih nekoliko desetljeća zaokuplja interes brojnih znanstvenika zbog sve veće otpornosti bakterija na antibiotike. Najčešći i najviše proučavani sekundarni biljni metabolite su polifenoli – brojna i raznolika skupina fitokemikalija s dokazanim antibakterijskim djelovanjem. Međutim, istraživači koji proučavaju antimikrobni učinak prirodnih spojeva biljnoga podrijetla susreću se s brojnim preprekama, koje je potrebno prepoznati i izbjeći. Na rezultate ispitivanja antimikrobne osjetljivosti mogu utjecati brojni čimbenici, a izbor odgovarajuće metode ispitivanja od presudnog je značaja. Nepostojanje postupnika/smjernica za testiranje antimikrobnog učinka bioaktivnih prirodnih spojeva uvelike utječe na ujednačenost, analizu i usporedbu brojnih objavljenih rezultata. U načelu, samo primjena standardiziranih metoda osigurava dobivanje pouzdanih rezultata. Cilj je ovoga preglednog rada sustavno i kritički prikazati različite metode koje se koriste za ispitivanje antimikrobnog učinka polifenola te istaknuti potrebu za njihovom standardizacijom

HOST AND BACTERIAL FACTORS IN PATHOGENESIS OF LISTERIOSIS

SAŽETAK Listerioza jest zoonoza do koje u većem broju slučajeva dolazi nakon konzumacije zagađenih namirnica. U zdravih odraslih osoba infekcija bakterijom Listeria monocytogenes posljeduje prolaznom, asimptomatskom kolonizacijom crijeva, ili slikom neinvazivna febrilnoga gastroenteritisa. Infekcija fetusa, novorođenčeta, ili imunokompromitirane osobe, može posljedovati razvojem invazivne infekcije praćene visokim postotkom smrtnosti. Zbog svojstva unutarstaničnoga parazitiranja, bakterija Listeria monocytogenes dugi se niz godina koristi kao oruđe za proučavanje stanične biologije i mehanizama stanične imunosti.ABSTRACT Listeriosis is a zoonosis usually transmitted through contaminated food or vertically from mother to foetus. In an immunocompetent, adult person the infection results in transitory asymptomatic gastrointestinal colonization or febrile, non-invasive gastroenteritis. The infection of the foetus, newborn or immunocompromised person can result in a serious invasive disease with high mortality rate. As a facultative intracellular pathogen, Listeria monocytogenes is widely used as model for studying cellular biology and mechanisms of cellular immunity

The Listeriosis Triangle: Pathogen, Host and the Environment

Listeria monocytogenes is a foodborne pathogen well known for its adaptability to diverse envirnoment and host niches and its high fatality rate among infected immunocompromised populations. Infection in the immunocompetent host occurs but risk factors for the disease primarily points to abnormalities in cell-mediated and innate immunity as major predispositions to listeriosis. After ingestion of contaminated food, this pathoge is able to cross the intestinal, blood-brain and placental barrier and leads to gastroenteritis, meningitis and maternofetal infections which may result in abortion and spontaneous stillbirth. Deispite the extensive use of this bacterium in the study of cell-mediated immunity and intracellular growth, our understanding of the host, pathogen and environmental factor that impact the pathogenesis of listeriosis is still inclomplete. This review will summarize current knowledge, including our own efforts, about pathogen, host and environmental factors that influence, and contribute to the pathogenesis of Listeria monocytogenes infection

The Listeriosis Triangle: Pathogen, Host and the Environment

Listeria monocytogenes is a foodborne pathogen well known for its adaptability to diverse envirnoment and host niches and its high fatality rate among infected immunocompromised populations. Infection in the immunocompetent host occurs but risk factors for the disease primarily points to abnormalities in cell-mediated and innate immunity as major predispositions to listeriosis. After ingestion of contaminated food, this pathoge is able to cross the intestinal, blood-brain and placental barrier and leads to gastroenteritis, meningitis and maternofetal infections which may result in abortion and spontaneous stillbirth. Deispite the extensive use of this bacterium in the study of cell-mediated immunity and intracellular growth, our understanding of the host, pathogen and environmental factor that impact the pathogenesis of listeriosis is still inclomplete. This review will summarize current knowledge, including our own efforts, about pathogen, host and environmental factors that influence, and contribute to the pathogenesis of Listeria monocytogenes infection