The Resistance of Bacteria to Antibiotics

Antibiotici se upotrebljavaju 60-ak godina, njima se mogu liječiti praktički sve danas poznate infekcije, no, također, na njih se trajno razvija i rezistencija. U tekstu se opisuje nastanak rezistencije, mehanizmi rezistencije, na primjeru S. pyogenes i H. pylori odnos rezistencije i uporabe antibiotika te potanko današnje stanje rezistencije glavnih bakterijskih izvanbolničkih i bolničkih patogenih bakterija u Hrvatskoj. Na temelju tih podataka upozorava se na potrebu promjene empirijske antimikrobne terapije akutnih nekompliciranih infekcija mokraćnog sustava, invazivnih salmoneloza i πigeloza.Antibiotics have been in use for about 60 years, being applied in treatment of almost all today known infections. However, resistance to them has been permanently developing as well. In the text are described the emergence of resistance, its mechanisms, the relationship of resistance and use of antibiotics through the example of S. pyogenes and H. pylori, and in detail is described the present resistance of main pathogenic bacteria in Croatia (in community and in hospitals). The obtained data point to the need of changing the empirical antimicrobic therapy of acute non-complicated infections of the urinary system, invasive salmonellosis and shigellosis

Značenje meticilin-rezistentnih sojeva Staphylococcus aureus (MRSA) u humanoj medicini

Staphylococcus aureus (S. aureus) is one of the most important bacterial opportunistic pathogens in humans. It easily adapts to the various environmental conditions. Very important is rapid development of resistance to different antimicrobial agents. Especially important is the resistance to beta-lactam antibiotics (so called methicillin-resistant S. aureus: MRSA). MRSA strains differ according to the setting they cause infections to healthcare-acquired strains, community-acquired strains and animal strains. Healthcare- acquired MRSA strains were responsible for the largest epidemic of healthcare-associated infections that ever occurred in the world; community-acquired MRSA strains are huge problem in USA, not so important in Europe. Animal MRSA strains are new addition to human pathogens, but they are not very frequent. In Croatia, MRSA strains are big problem in hospitals but with the tendency of decreasing in recent years; community- acquired MRSA strains are so far very rare, and infections caused by animal MRSA strains are still not described in humans, although they are present in pig farms.Staphylococcus aureus (S. aureus) jedan je od najznačajnijih bakterijskih oportunističkih patogena u ljudi. Vrlo se lako adaptira na različite uvjete u okolini, a posebno je važno njegovo brzo stjecanje otpornosti na različite antibiotike. Osobito je važna otpornost na betalaktamske antibiotike (takozvani meticilin-rezistentni S. aureus: MRSA). Sojevi MRSA-e razlikuju se prema sredini u kojoj uzrokuju infekcije: bolnički stečeni, stečeni u izvanbolničkoj populaciji te oni povezani s domaćim životinjama. Bolnički MRSA izazvao je najveću epidemiju bolničkih infekcija ikada opisanu u svijetu; izvanbolnički MRSA velik je problem u SAD-u, manji u Europi. Životinjski sojevi MRSA-e novi su dodatak ljudskim patogenima, no ne s velikom učestalošću u svijetu. U Republici Hrvatskoj MRSA je velik problem u bolničkim ustanovama, s laganom tendencijom smanjenja posljednjih godina. Izvanbolnički MRSA zasad je vrlo rijedak, a infekcije životinjskim sojevima, premda su dokazane na svinjogojskim farmama, nisu još opisane

The place and role of serologic methods in detecting Helicobacter pylori infection

The aim of the study was to determine the place and role of serologic methods in detecting Helicobacter pylori (H. pylori) infection, on the basis of estimated enzyme-linked immunosorbent assay (ELISA) and complement fixation test (CFT) sensitivity and specificity. A total of 549 patients were included in the study. ELISA and CFT as serologic methods were compared with invasive methods (rapid urease test--CLO test, culture, histology). The sensitivity of serologic methods was above 90%, and their specificity was around 80%. Study results confirmed the value, reliability and usefulness of serologic methods in the detection of H. pylori infection

The Place and Role of Serologic Methods in Detecting Helicobacter Pylori Infection

The aim of the study was to determine the place and role of serologic methods in detecting Helicobacter pylori (H. pylori) infection, on the basis of estimated enzyme-linked immunosorbent assay (ELISA) and complement fixation test (CFT) sensitivity and specificity. A total of 549 patients were included in the study. ELISA and CFT as serologic methods were compared with invasive methods (rapid urease test – CLO test, culture, histology). The sensitivity of serologic methods was above 90%, and their specificity was around 80%. Study results confirmed the value, reliability and usefulness of serologic methods in the detection of H. pylori infection

DIAGNOSTIC APPROACH AND THERAPY FOR CYTOMEGALOVIRUS (CMV) INFECTION FOLLOWING ALLOGENEIC STEM CELL TRANSPLANTATION

Unatoč napretku u dijagnostici i sprječavanju CMV-bolesti u posljednjih nekoliko desetljeća, CMV-infekcija i dalje je velik dijagnostički i terapijski problem u primatelja alogenih krvotvornih matičnih stanica (aloKMS). Pored znatnog pobola koji se očituje u izravnim učincima CMV-infekcije (hepatitis, gastrointestinalna bolest, pneumonija, retinits), CMV neizravnim djelovanjem povećava osjetljivost prema oportunističkim infekcijama te povećava rizik od odbacivanja presatka i smrtnosti pridružene presadbi. Također, zbog mijelosupresije, nefrotoksičnosti ili pojave CMV-rezistentnih sojeva javljaju se ograničenja u upotrebi antivirusnih tvari koje se rabe za kontrolu CMV-infekcije. Cilj je ovoga rada prikazati probleme vezane uz CMV-infekciju koji se javljaju u primatelja aloKMS s posebnim naglaskom na dijagnostiku i liječenje odnosno sprječavanje nastanka CMV-bolesti.In spite of improvements in diagnostics and prevention of CMV disease in recent decades, CMV infection still remains major concern in terms of diagnosis and therapy in recipients of allogeneic stem cells. Besides considerable morbidity with direct effects of CMV infection (hepatitis, gastrointestinal disease, pneumonia, retinitis), there are also indirect effects such as increased susceptibility to opportunistic infections and an increased risk of graft rejection and transplant-related mortality. Also, myelosuppression, nephrotoxicity and emergence of drug-resistant CMV strains may limit the use of antiviral agents for the control of CMV infection. The aim of this paper is to show the problems associated with CMV infection in recipients of allogeneic stem cells with special emphasis on diagnostic procedures and treatment or prophylaxis of CMV disease

First report on PVL-positive methicillin-resistant Staphylococcus aureus of SCCmec type V, spa type t441 in Croatia

Purpose The aim of the study was to investigate the molecular epidemiology of community- associated MRSA in Primorsko-Goranska County of Croatia during a six-year period(2001-2007). Methods In period from 2001 and 2007, 46 MRSA isolates were collected in Rijeka, strains were subjected to susceptibility testing according to CLSI guidelines, mecA gene detection and SCCmec typing as well as detection of PVL. Strains were typed by Pulse Field Gel Electrophoresis (PFGE) and spa typing. Results All isolates were susceptible to vancomycin, linezolid, mupirocin, nitrofurantoin, only one strain was resistant to fusidic acid and co-trimoxazole. Results of SCCmec typing showed the presence of SCCmec type IV in 26 MRSA strains, SCCmec type V in three strains, and 13 strains comprised SCCmec I. SCCmec type II and III were not observed. Four MRSA strains were non-typeable by applied SCCmec typing methods. PVL was detected in 4 strains, two SCCmec IV and two SCCmec V. PFGE analysis, grouped MRSA strains into six similarity groups and 18 singletons. Dominating spa types in this collection of strains were t015, with 15 strains, followed by t041(N=7), t051,(N=2 ), t2850(N=2), t008(N=2)and single isolates t441, t002, t448, t018, t019, t355, t390, t026, t449, t148. We also detected two new spa types, t3510 and t3509, respectively. Conclusions This is the first report on SCCmec type V in Croatia, and, to our knowledge, first report of PVL-positive mehicillin-resistant Staphylococcus aureus SCCmec type V and t441(ST59-MRSA-V) in this part of Europe

Cotton textiles modified with citric acid as efficient anti-bacterial agent for prevention of nosocomial infections

Aim. To study the antimicrobial activity of citric acid (CA) and sodium hypophosphite monohydrate (SHP) against gram-positive and gram-negative bacteria, and to determine the influence of conventional and microwave thermal treatments, on the effectiveness of antimicrobial treatment of cotton textiles. ----- Method. Textile material was impregnated with CA and SHP solution and thermally treated by either conventional or microwave drying/curing treatment. Antibacterial effectiveness was tested according to ISO 20743:2009 standard, using absorption method. The surfaces were morphologically observed by scanning electron microscopy, while physical characteristics were determined by wrinkle recovery angles method (DIN 53 891), tensile strength (DIN 53 837), and whiteness degree method (AATCC 110-2000). ----- Results. Cotton fabric treated with CA and SHP showed significant antibacterial activity against MRSA (6.38 log10 treated by conventional drying and 6.46 log10 treated by microwave drying before washing, and 6.90 log10 and 7.86 log10, respectively, after 1 cycle of home domestic laundering washing [HDLW]). Antibacterial activity was also remarkable against S. aureus (4.25 log10 by conventional drying, 4.58 log10 by microwave drying) and against P. aeruginosa (1.93 log10 by conventional drying and 4.66 log10 by microwave drying). Antibacterial activity against P. aeruginosa was higher in samples subjected to microwave than in conventional drying. Antibacterial activity was reduced after 10 HDLW cycles but the compound was still effective. The surface of the untreated cotton polymer was smooth, while minor erosion stripes appeared on the surfaces treated with antimicrobial agent, and long and deep stripes were found on the surface of the washed sample. ----- Conclusion. CA can be used both for the disposable (non-durable) materials (gowns, masks, and cuffs for blood pressure measurement) and the materials that require durability to laundering. The current protocols and initiatives in infection control could be improved by the use of antimicrobial agents applied on cotton carbohydrate polymer

Distributed lags time series analysis versus linear correlation analysis (Pearson's r) in identifying the relationship between antipseudomonal antibiotic consumption and the susceptibility of Pseudomonas aeruginosa isolates in a single Intensive Care Unit of a tertiary hospital

The relationship between antibiotic consumption and selection of resistant strains has been studied mainly by employing conventional statistical methods. A time delay in effect must be anticipated and this has rarely been taken into account in previous studies. Therefore, distributed lags time series analysis and simple linear correlation were compared in their ability to evaluate this relationship. Data on monthly antibiotic consumption for ciprofloxacin, piperacillin/tazobactam, carbapenems and cefepime as well as Pseudomonas aeruginosa susceptibility were retrospectively collected for the period April 2006 to July 2007. Using distributed lags analysis, a significant temporal relationship was identified between ciprofloxacin, meropenem and cefepime consumption and the resistance rates of P. aeruginosa isolates to these antibiotics. This effect was lagged for ciprofloxacin and cefepime [1 month (R=0.827, P=0.039) and 2 months (R=0.962, P=0.001), respectively] and was simultaneous for meropenem (lag 0, R=0.876, P=0.002). Furthermore, a significant concomitant effect of meropenem consumption on the appearance of multidrug-resistant P. aeruginosa strains (resistant to three or more representatives of classes of antibiotics) was identified (lag 0, R=0.992, P<0.001). This effect was not delayed and it was therefore identified both by distributed lags analysis and the Pearson's correlation coefficient. Correlation coefficient analysis was not able to identify relationships between antibiotic consumption and bacterial resistance when the effect was delayed. These results indicate that the use of diverse statistical methods can yield significantly different results, thus leading to the introduction of possibly inappropriate infection control measures

Emergence of Uropathogenic Extended-Spectrum b Lactamases-Producing Escherichia coli Strains in the Community

The aim of this study was to determine the virulence characteristics and resistance pattern of the extended-spectrum b lactamases (ESBLs)-producing Escherichia coli strains isolated from urine of outpatients in the Zagreb region during a five-month period, and to compare them with the non ESBLs-producing E. coli strains isolated in the same period. Out of 2,451 E. coli strains isolated from urine of nonhospitalized patients with significant bacteriuria, a total of 39 ESBLsproducing strains (1.59%) were detected by a double-disk diffusion technique and by the broth-dilution minimal inhibitory concentration reduction method. The 45 non ESBLs-producing strains were randomly chosen, and phenotype of the two groups of strains was characterized and compared. Serogroup O4, hemolysin production, expression of P- and type 1 fimbriae as well as resistance to gentamicin and amikacin were significantly more prevalent characteristics among the ESBLs-producing strains than among non ESBLs-producing strains (p<0.01), while higher prevalence of trimethoprim- sulfamethoxazole resistance among ESBLs-producing strains was not statistically significant (p>0.05). Chromosomal DNA analysis by pulsed-field gel electrophoresis exhibited a great genomic similarity among ESBLs-producing strains and revealed that those highly virulent and resistant E. coli strains isolated from urine of outpatients in the Zagreb region had a clonal propagation