Significance of Screening Tests and the Incidence of New Delhi Metallo-beta-lactamase-Producing Gram-negative Bacilli in the Surgery and Transplantation Wards of a Warsaw Medical Center During the Period From April 2014 to May 2017.

BACKGROUND: The first New Delhi metallo-beta-lactamase (NDM)-producing bacteria were isolated in 2008 in the world, and in 2011 in Poland. Due to the high clonal diversity (17 types) of their blaNDM gene, encoded on (Tn125-like) mobile genetic elements, these strains usually exhibit resistance to nearly all available antibiotics, which is particularly dangerous for organ transplant recipients. PURPOSE: To assess of the prevalence of Gram-negative NDM-positive bacilli in surgery/transplantation wards of a teaching hospital in Warsaw and to ascertain the significance of screening tests on the rates and nature of colonization. MATERIALS AND METHODS: The evaluated strains were isolated from 30 patients (between April 2014 and May 2017). The species were identified with VITEK-MS, antibiotic susceptibility was determined with VITEK 2, disk-diffusion, and/or E-test methods, according to EUCAST guidelines. The presence of the blaNDM-1 gene was confirmed using the polymerase chain reaction technique. RESULTS AND CONCLUSIONS: There were 77 blaNDM-1-positive Klebsiella pneumoniae strains isolated from 30 patients. Cultures from individual patients, mainly from rectal swabs (53.9%) and urine samples (39.8%), yielded 1-11 isolates. Fifteen patients were already colonized on admission, and the other 15 developed a symptomatic infection. In total, 24 (80%) patients were carriers, and their colonizations persisted for <1-20 months. Most isolates were susceptible only to colistin, gentamicin, amikacin, tigecycline, and/or sulfamethoxazole/trimethoprim. Gastrointestinal-tract-colonizing K pneumoniae are the main reservoir of the blaNDM-1 gene. Following the introduction of on-admission mandatory screening for carbapenem-resistant strains, the rates of NDM-producing K pneumoniae isolation increased (7.5-fold), while the rates of isolation from patients with symptomatic infections considerably decreased (2.8-fold).

Resistance to Aminoglycosides of Methicillin-Resistant Strains of Staphylococcus aureus, Originating in the Surgical and Transplantation Wards of the Warsaw Clinical Center-A Retrospective Analysis.

INTRODUCTION: Aminoglycoside resistance (AR) is common in health care-associated methicillin-resistant Staphylococcus aureus (HA-MRSA). AR is most often associated with the production of antibiotic modifying enzymes: bidomain AAC(6')-Ie/APH(2″)-Ia acetyltransferase and phosphotransferase, ANT(4')-Ia nucleotidyltransferase, and APH(3″)-IIIa phosphotransferase. AIM: Determination of aminoglycoside sensitivity, presence of genes encoding enzymes, and molecular typing of HA-MRSA strains derived from patients hospitalized in surgical and transplantation wards. MATERIALS AND METHODS: Fifty-four HA-MRSA strains, isolated from various materials from patients in the surgical and transplantation wards of Warsaw's clinical hospital, hospitalized between 1991 and 2007. The MIC values of gentamicin-GEN/tobramycin-TOB/amikacin-AK/netilmicin-NET were determined by the E-test (CLSI/EUCAST). Genes mecA/aacA-aphD/aadD/aph(3″)-IIIa were detected using PCR. SCCmec types were determined according to the Oliveira method and the sequence type (ST)/clonal complex (CC) by the MLST method. RESULTS: Of the isolates tested, 36 (66.7%) showed resistance to at least one aminoglycoside: TOB (57.4%), GEN (53.7%), AK (55.6%), NET (24.1%). The aacA-aphD gene was present in 29 MRSA-GEN-R (most often in combination with aadD, 15/29 or aph(3″)-IIIa, 10/29); the aacA-aphD gene was the only determinant of resistance in 1 isolate. The AR variants mainly belonged to the CC8 clonal complex (ST239/247/241/254/8) and most frequently contained SCCmec type III (3A) cassettes. CONCLUSIONS: Resistance to at least one aminoglycoside was present in 66.7% of HA-MRSA and in more than 22% to all of them. The presence of the aacA-aphD gene was sufficient to express the resistance phenotype to GEN/TOB/AK/NET. Resistant isolates were closely related to each other.

Effect of Selective Antibiotic Pressure on the MLS-B Phenotype in Methicillin-Resistant Staphylococcus aureus Strains Originating From Patients From Transplantation Wards: 24 Years of Observations.

INTRODUCTION: Staphylococcus aureus infection, and health care-associated-methicillin resistant S aureus (HA-MRSA) in particular, is a serious risk for patients treated with organ transplantation. The frequent combined resistance of these bacteria to macrolides, lincosamides, and streptogramin-B (MLS-B) limits the use of these drugs in therapy. AIM: Evaluation of the mechanism of MLS-B resistance among HA-MRSA strains derived from patients treated in surgical-transplantation wards, over a 24-year period, and assessment of correlation of clindamycin use and resistance phenotype. MATERIALS AND METHODS: One hundred and twelve HA-MRSA strains from patients in surgical-transplantation wards (clinical hospital, Warsaw), hospitalized in the period from 1991 to 2014. Methicillin-resistance was determined using phenotypic and genetic methods by detecting the mecA gene. Erythromycin/clindamycin resistance was determined by E-test, the iMLS-B (inductive) and cMLS-B (constitutive) phenotypes by the D-test method. The number of defined daily doses (DDD), statistically per 1000 person-days, was calculated in accordance with the WHO guidelines. RESULTS: Resistance to erythromycin/clindamycin in MRSA strains increased from 1991 to 2004-2007 from 64.7/11.8% to 100/76.9%, respectively. The frequency of the cMLS-B phenotype in the years 1991/2010-2011/2012 was 5.9%/76.9%/69.7%, respectively, and correlated with the increased use of clindamycin in the examined wards. In 2012, the percentage of MLS-B-sensitive isolates increased from 3.9 to 21.7%, while constitutive resistance decreased to 69.7%, which correlated with a decrease in the use of clindamycin. CONCLUSIONS: The proportion of cMLS-B to iMLS-B phenotypes in HA-MRSA is related to the amount of clindamycin used in hospital wards. Limiting the selection pressure of antibiotics can lead to complete loss of resistance or return to the inductive mechanism of its regulation.

Drug Susceptibility Assessment in Stenotrophomonas Maltophilia Strains Isolated From the Blood of Organ Transplantation Recipients in a Warsaw Teaching Hospital During 2011 to 2014.

BACKGROUND: Blood infections with multidrug-resistant Gram-negative carbapenem-resistant bacilli are particularly dangerous and challenging to treat in organ transplant recipients. Resistance to carbapenems may be acquired, for example, in Enterobacteriaceae, Pseudomonas, or Acinetobacter spp. or innate, for example, in Stenotrophomonas maltophilia. The purpose of this study was to analyze blood infections caused by S maltophilia in organ transplant recipients and to compare drug susceptibility of these bacteria and the same species isolated from the blood of other inpatients. METHODS: A total of 26 S maltophilia strains isolated from blood samples of 26 patients (including 14 liver or kidney transplant recipients) hospitalized during 2011 to 2014 were evaluated in this study. Antibiotic susceptibility was determined via E-test and disk diffusion methods. RESULTS: Stenotrophomonas maltophilia strains isolated from blood exhibited sensitivity to trimethoprim/sulfamethoxazole (100%), levofloxacin (96.2%), ciprofloxacin (92.3%), ticarcillin/clavulanic acid (80.8%), and ceftazidime (53.9%). CONCLUSIONS: Because appropriate antibiotic therapy in the case of S maltophilia differs from the standard empirical therapy administered in the case of most other Gram-negative bacilli, early identification of this pathogen is of particular significance. The use of antibiotics to which this pathogen is sensitive eliminates the infection and helps avoid graft loss.

Epidemiological and Drug-Resistance Types of Methicillin-Resistant Staphylococcus Aureus Strains Isolated From Surgical and Transplantation Ward Patients During 2010 to 2011.

BACKGROUND: The increasing prevalence of multi-drug-resistant methicillin-resistant Staphylococcus aureus (MRSA) is a substantial problem in hospitals worldwide, especially in wards with immunocompromised patients undergoing organ transplant. Epidemiological characteristics and antibiotic susceptibility profiles of hospital-acquired (HA) MRSA strains isolated from surgical/transplantation ward patients were studied. METHODS: We analyzed 26 HA-MRSA strains isolated from 22 patients hospitalized at 3 different surgical and transplantation wards at a Warsaw clinical hospital during 2010 to 2011. Eleven patients were MRSA-asymptomatic carriers. Strain relatedness was evaluated through the use of multi-locus sequence typing (MLST), multi-locus variable-number tandem repeat analysis (MLVA), and random amplified polymorphic DNA/arbitrarily primed PCR (RAPD) methods. Antibiotic susceptibility was assessed the use of routine diagnostic methods. RESULTS: The evaluated strains belonged to 4 clonal complexes (CCs) and 4 sequence types (STs): CC30/ST36 (65.4%), CC8/ST8 (15.4%), CC5/ST1827 (11.5%), and CC1/ST1 (7.7%). Six MLVA types and 6 RAPD types were isolated. A ciprofloxacin-, erythromycin-, and clindamycin-resistant CC30/ST36 clone (MLVA type 1, RAPD type 1A) was isolated in all wards. The isolated HA-MRSA strains were most often resistant to ciprofloxacin (100%), erythromycin (96.2%), clindamycin (84.6%), and gentamycin (30.8%). CONCLUSIONS: A ciprofloxacin-, erythromycin-, and clindamycin-resistant HA-MRSA ST36 CC30 clone, which prevailed on transplantation wards in the years 2010 to 2011, is probably one of the international epidemic clones named UK EMRSA-16 or USA200.

Molecular analysis of carbapenem-resistant strains of Pseudomonas aeruginosa isolated from patients hospitalized in various transplantation wards between 2008 and 2011.

BACKGROUND: Recent years have seen a concerning increase in the number of carbapenem-resistant Pseudomonas aeruginosa strains. P aeruginosa is one of the most dangerous factors causing nosocomial infections, and immunosuppressed patients constitute a special risk group. The purpose of our study was to conduct a molecular analysis of 22 clinical isolates of carbapenem-resistant P aeruginosa obtained between 2008 and 2011. MATERIALS AND METHODS: Metallo-beta-lactamase (MBL) phenotype tests were conducted. A polymerase chain reaction technique was used to detect VIM, IMP, NDM, and GIM carbapenemase-encoding genes. The minimum inhibitory concentrations were determined for imipenem, meropenem, and doripenem. Molecular typing was conducted with the use of restriction fragment length polymorphism/pulsed-field gel electrophoresis (RFLP-PFGE). RESULTS: Of the 22 strains initially resistant to at least one carbapenem, we selected 18 that exhibited the MBL phenotype. Of those 18, we identified 15 strains expressing VIM carbapenemase-encoding genes. None of the other evaluated genes were detected. VIM-positive isolates exhibited higher levels of resistance than the other ones. The RFLP technique revealed 10 different PFGE types and 6 epidemic foci. Identical strains were isolated over the period of up to 3 years. CONCLUSIONS: The reason for resistance to carbapenems in the majority (68%) of P aeruginosa strains isolated at the evaluated hospital was the presence of VIM carbapenemase. It is safe to say that the VIM carbapenemase is responsible for a higher level of resistance than unidentified mechanisms. Carbapenem-resistant strains of P aeruginosa spread clonally within individual wards and are likely to be of hospital origin.

Molecular and phenotypic characteristics of methicillin-resistant Staphylococcus aureus strains isolated from hospitalized patients in transplantation wards.

OBJECTIVES: Hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) frequently causes therapeutic problems and provides information about the epidemiological condition of the ward. MATERIALS AND METHODS: HA-MRSA isolated from patients on transplantation wards in 1991, 1994, 1996, and from 2005 to 2007 were compared using molecular methods such as restriction fragment length polymorphism-pulse field gel electrophoresis, multilocus sequence typing (MLST), multiplex polymerase chain reaction (PCR) for detection type of staphylococcal chromosomal cassette mec, and PCR for detection. RESULTS: The analysis covered HA-MRSA strains, each from a different patient. All organisms were typed using molecular methods. MLST results were compared with an international base. The examined strains belonged to five different worldwide known clonal complexes: CC8 (78%), CC5 (12%), CC1 (4%), CC30 (2%), and CC51 (4%). All could be recognized as representatives of a clonal complex CC8 clones: ST239-III (sequence type 239 and SCCmec type III named EMRSA-1, -4, -11, Brasilian, Hungarian) occurred with a frequency of 35.9%, ST254-IV (EMRSA-10, Hannover) occurred in 33.3%, ST247-I (EMRSA-5,-7, Iberian) occurred in 20.5%, ST241-III (Finland-UK) occurred in 5.15%, and ST8-IV (EMRSA-2,-6) occurred in 5.15%. CONCLUSION: The predomination of different clones of HA-MRSA in the particular years was observed. In 1991, the EMRSA-10 (Hannover) clone predominated (53.3%). The Brasilian-Hungarian (EMRSA-1, -4, -11) clone predominated in 1994 (50%) as well as from 2005 to 2007 (41.3%), whereas in 1996 the Iberian clone was most frequent (53.9%).

Evaluation of the prevalence of insertion element IS16 in vancomycin-resistant enterococci strains of Enterococcus faecium isolated from transplantology patients from a Warsaw Hospital between 2010 and 2012.

The study included 79 vancomycin-resistant Enterococcus faecium (VRE) strains isolated from 33 patients after kidney (n = 19) or liver (n = 14) transplantation; these patients were hospitalized between 2010 and 2012. The strains were obtained from infected persons as well as from carriers. All examined strains were tested for the susceptibility to antimicrobials active against enterococci and for the presence of vanA and vanB genes as well as the presence of the insertion sequence IS16 considered as one of the markers of hospital-associated strains. All 79 VRE strains of E faecium possessed IS16 and the vanA (vanB-negative) determinant. All tested strains were resistant to at least three groups of drugs; therefore, they were recognized as multidrug resistant. All isolates were resistant to glycopeptides, ampicillin, and most were resistant to tetracyclines, macrolides, nitrofurans, and high concentrations of aminoglycosides. The presence of insertion element IS16 and multiple resistance determinants prove that strains colonizing or infecting solid organ recipients were typical nosocomial pathogens.

Specific character of anaerobic bacterial infections in patients treated in transplantation wards at one of the clinical hospitals in Warsaw.

Immunocompromised patients and patients undergoing invasive procedures are predisposed to bacterial infections, due to the possibility of micro-organism translocation from their physiological habitat. Infectious complications may occur both in the early and late post-transplantation periods. The purpose of this study was to evaluate the proportion as well as susceptibility profiles of obligatory anaerobes in the etiology of infections in patients hospitalized at transplantation wards of a large clinical hospital in Warsaw. A total of 104 strains of obligatory anaerobes derived from patients hospitalized in two transplantation clinics at a clinical hospital in Warsaw were evaluated. The strains were isolated from 87 clinical samples collected from 84 patients of two transplantation wards between 2007 and 2012. A total of 104 obligatory anaerobic bacterial strains were isolated and identified, with Gram-positive and Gram-negative bacteria constituting 60.6% and 39.4% of the isolates, respectively. Almost exclusively non-spore-forming anaerobes were detected in evaluated samples. The present study showed all isolated Gram-positive bacteria to be susceptible to ß-lactam antibiotics. Metronidazole-resistant bacteria were found among the genera Propionibacterium and Actinomyces. All Gram-negative rods were susceptible to imipenem and metronidazole. Among them, Bacteroides spp. and Parabacteroides distasonis showed resistance to penicillin G (100%). Because of their pathogenicity and altered antibiotic susceptibility profiles, the bacteria of the genera Bacteroides and Parabacteroides are of greatest clinical importance. Approximately 25% of isolates exhibit also resistance to clindamycin. Because of the growing rates of clindamycin resistance, the role of metronidazole in the treatment of Bacteroides spp. is of increasing importance.

Blood infections in patients treated at transplantation wards of a clinical hospital in Warsaw.

Establishment of the etiology in blood infection is always advisable. The purpose of this study was to evaluate the proportion of different bacterial species, including aerobic and anaerobic bacteria in blood cultures of patients hospitalized in transplantation wards of a large clinical hospital between 2010 and 2012. A total of 1994 blood samples from patients who were treated at one of two transplantation wards of a large hospital in Warsaw were analyzed using an automated blood culture system, BacT/ALERT (bioMerieux, France). The 306 bacterial strains were obtained from the examined samples. The highest proportion were bacteria from the family Enterobacteriaceae (112 strains; 36.6%) with Escherichia coli (61 strains), Klebsiella pneumoniae (30 strains), and Enterobacter cloacae (10 strains) most commonly isolated. The non-fermenting bacilli constituted 21.6% (66 strains), with most common Stenotrophomonas maltophilia (31 strains), Pseudomonas aeruginosa (14 strains), Achromobacter spp. (12 strains), and Acinetobacter baumannii (3 strains). Most frequent Gram-positive bacteria were staphylococci (25.2%). Of 77 staphylococcal strains, 56 were coagulase-negative staphylococci and 21 Staphylococcus aureus. Other Gram-positive bacteria included enterococci (14 strains) and Streptococcus pneumoniae (1 strain). Obligatory anaerobic bacteria were represented by 19 strains (6.2% of total isolates). Among all Enterobacteriaceae, 49 isolates (43.7%) produced extended-spectrum ß-lactamases (ESBLs). Resistance to methicillin was detected in 62% of S aureus isolates and in 46% of coagulase-negative staphylococci. Of 14 enterococci cultured from blood samples, 2 strains (14.3%) were resistant to vancomycin. Both were Enterococcus faecium. Resistant strains of Gram-negative and Gram-positive bacteria are significant problems for patients in the transplantation ward.

Acinetobacter baumannii multidrug-resistant strain occurrence in liver recipients with reference to other high-risk groups.

INTRODUCTION: The increasing clinical significance of Acinetobacter baumannii species is due to its ability to survive in hospital environments, its species-specific multidrug resistance, and its ability to instantly develop various drug-resistance mechanisms through antibiotic pressure. MATERIALS AND METHODS: We identified 16 A baumannii strains isolated from patients presenting postoperative infections in 2010. A baumannii isolates were obtained from clinical specimens by standard microbiologic methods. As previously described, we performed polymerase chain reaction (PCR) analysis for carbapenemase-encoding genes (VIM, IMP, SPM, OXA23, OXA24, OXA51, OXA58) in Acinetobacter spp. RESULTS: The double-disk synergy test phenotypic method did not detect any A baumannii strains producing metallo-beta-lactamaus cultured from swabs from all the patient groups. No products of PCR amplification with specific starters for VIM, IMP, and SPM (Sao Paulo metallo-ß-lactamase) genes were found. All analyzed strains were colistin-sensitive. Among five strains from liver recipients, one was imipenem- and meropenem-resistant. Four among six strains isolated from cancer patients were resistant to imipenem and/or meropenem; 1/5 were imipenem-and meropenem-resistant; 1, meropenem-resistant and imipenem-sensitive; 1, meropenem- and imipenem-resistant; and 1 with intermediate resistance to both meropenem and imipenem among swabs cultured from patients with postoperative complication after bone fracture. Fifteen among 16 analyzed A baumannii strains had an OXA51 gene. Two among five A baumannii strains isolated in liver recipients had only an OXA51 gene; one, OXA51 and OXA24 genes; one, OXA51 and OXA23 genes.

Comparison of bacteria isolated from urinary tract infections in patients on transplant versus urologic wards.

OBJECTIVE: Urinary tract infections (UTI) are the most common hospital infections. Complications include sepsis and shock. Immunosuppressed transplant surgery patients may experience loss of the graft due to UTI. The purpose of this study was to determine the main microorganisms responsible for UTIs among patients of transplant wards compared to urologic wards. Additionally, drug susceptibility profiles of the most frequent microorganisms were analyzed. MATERIALS AND METHODS: We analyzed the results of positive urine cultures from patients on 2 transplant versus 1 urologic ward in 2010. RESULTS: The most common pathogen in urine samples from all 3 wards was Escherichia coli. Often, other Gram-negative bacilli of the genus Klebsiella spp, were cultured as well as Gram-positive cocci (Enterococcus spp). Yeasts of the genus Candida were only found in urine of patients of transplant wards. The percentage of resistant bacteria was much higher among bacteria from transplant patients. CONCLUSIONS: The high level of antimicrobial resistance of microorganisms isolated from the urine of transplant patients and the relatively high incidence of fungal infections, demand an especially quick, accurate microbiological diagnosis for this group of patients.

Strains of Klebsiella pneumoniae producing extended spectrum beta-lactamases, isolated from organ recipients.

OBJECTIVE: The aims of this work were to define the effectiveness of identification of the extended-spectrum beta-lactamases (ESBL) phenotype, and to define the genotype of Klebsiella pneumoniae ß-lactamase. MATERIALS AND METHODS: We identified ESBL phenotypes in 110 strains of K pneumoniae isolated from samples from patients of transplantation wards, using the double-disk synergy test (DDST). For the chosen strains, polymerase chain reaction (PCR) was applied to detect genes determining SHV, CTX-M, and TEM. RESULTS: We showed synergism of clavulanic acid and investigated antibiotics including ceftazidime (89.1%), cefotaxime (80%), and aztreonam (82.7%) against ESBL-positive strains PCR revealed that TEM and CTX-M were present in 88.89% of strains. CONCLUSIONS: The ESBL mechanism of resistance is frequent among K pneumoniae strains isolated from transplant recipients. Strains with simultaneous synthesis of more than one beta-lactamase predominated.

Participation of strictly anerobic bacteria in infections among hospitalized transplant patients in a clinical hospital in Warsaw.

BACKGROUND: Many strictly anerobic bacteria are a part of the human commensal microflora. Especially multitudinously they inhabit the skin, mucous membranes, gastrointestinal tract, respiratory, and genital tracts. Infections with these bacteria may occur after escape of the bacteria from their natural habitat. There are often mixed anerobic and aerobic infections. After rupture of the gastrointestinal tract or surgery, the organisms can cause significant pathology including abscesses and bacteremia. OBJECTIVE: The aim of this study was to estimate the prevalence of gram-negative strictly anerobic bacteria isolated from different samples collected from patients on transplant wards. MATERIALS AND METHODS: Samples from patients with suspected infections. Underwent isolation and identification of microorganisms under anerobic conditions using standard laboratory methods. RESULTS: Gram-negative rods were observed in 46% of clinical samples, most frequently Bacteroides genus as well as Fusobacterium necrophorum/F.nucleatum and F.mortiferum (14%). Most species of the genus Bacteroides were accompanied by Escherichia coli, less frequently with other aerobic gram-negative rods or gram-positive cocci. CONCLUSION: Gram-negative bacteria were frequently isolated in the samples. Because they are the part of the normal flora, this observation indicated the endogenous nature of infections resulting from bacterial translocation out of their natural habitat.

The dominant sequence types of vancomycin-resistant Enterococcus faecium among transplantation ward patients.

OBJECTIVES: Vancomycin-resistant enterococci (VRE) frequently cause therapeutic problems and provide information about the epidemiological condition of the ward. MATERIALS AND METHODS: VRE isolated from patients on transplantation wards in 2007-2008 were compared using 2 molecular methods: RFLP-PFGE (restriction fragment length polymorphism-pulse field gel electrophoresis) and MLST (multilocus sequence typing). RESULTS: The analysis covered 29 Enterococcus faecium strains resistant to glycopeptides, each from a different patient. All organisms were typed using 2 molecular methods. MLST results were compared with an international base. The 30 examined strains belonged to 8 different worldwide known sequence types. All could be recognized as representatives of a single clonal complex CC17. CONCLUSION: Both methods of typing appeared to be useful to asses the epidemiological condition of the investigated wards.

A threat of the Klebsiella pneumoniae carbapenemase-producing strains among transplant recipients.

BACKGROUND: Infections due to Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae are associated with increased therapeutic failure and mortality. Our laboratory recognized several strains producing KPC, most of which originated from transplantation ward patients. MATERIALS AND METHODS: All strains of K pneumoniae resistant to at least 1 carbapenem isolated in 2010 were examined for KPC production by disc diffusion and then verified by molecular methods. RESULTS: All positive strains originated from 7 patients. Six of them were from transplantation wards. None of the KPC-producing strains was isolated from the patient's blood. CONCLUSIONS: A quick, accurate diagnosis of KPC-producing strains enabled immediate isolation of carriers or infected persons. Isolation prevented spread of dangerous strains among immunocompromised patients and reduced the possibility of serious infections.

Mechanisms of resistance to antimicrobial drugs in pathogenic Gram-positive cocci.

Many species of Gram-positive cocci are pathogenic. The most important are staphylococci, streptococci, and enterococci. Widespread usage of antibiotics was the main cause for the appearance and spread of resistance to almost all antimicrobials. The occurrence, mechanisms, and genetic background of resistance to antimicrobial drugs other than beta-lactams and glycopeptides among pathogenic staphylococci, streptococci, and enterococci are discussed in the text. Well-established agents (such as macrolides, lincosamides, streptogramins, aminoglycosides, quinolones, mupirocin, chloramphenicol) as well as new agents (linezolid, daptomycin, quinupristine/dalfopristine, ratapamulin, tigecycline, iclaprim and new generations of quinolones) are considered.

Surgical site infections in the early posttransplant period after simultaneous pancreas-kidney transplantation.

OBJECTIVE: This study evaluated the frequency of microbial isolates and their susceptibility profiles among cultures from the "surgical site" of 26 simultaneous pancreas-kidney (SPKT) recipients in the early posttransplant period. PATIENTS AND METHODS: Data on microbiologic cultures of 26 adult patients undergoing SPKT were collected prospectively from 2001 to the end of 2006. The isolation and identification of cultured micro-organisms was performed according to standard microbiological procedures and commercially available tests. Susceptibility of the strains to antibacterial agents was made by the Clinical and Laboratory Standards Institute (CLSI) guidelines. RESULTS: All patients were followed prospectively for the first 4 weeks after surgery yielding 168 microbial isolates from the surgical site. The most commonly isolated organisms were Gram-positive bacteria (65.5%) with domination of staphylococci (52.7%) as methicillin-resistant S aureus and methicillin-resistant coagulase-negative staphylococci. The second most common were enterococci (33.6%) with the presence of an high level aminoglycoside-resistant strains (64.9%) and vancomycin-resistant strains (2.7%). Gram-negative bacteria comprised 19% of positive cultures; among them were isolated extended spectrum beta-lactamase producers and carbapenem-resistant strains. Yeast-like fungi comprised 15.5% of positive cultures. In conclusion, we observed predominantly Gram-positive bacteria, comprising 65.5% of isolates. The increased proportion of multi-drug-resistant bacterial isolates may be due to the frequent prophylaxis of bacterial infections in patients.

Urinary tract infections in the early posttransplant period after simultaneous pancreas-kidney transplantation.

OBJECTIVE: Urinary tract infection (UTI) is among the common infection in simultaneous pancreas-kidney transplantation (SPKT). PATIENTS AND METHODS: The study included 26 adult patients undergoing SPKT between September 2001 and December 2006. All the patients were followed prospectively for UTI during the first 4 weeks after surgery. Urine samples were investigated for bacteriologic cultures. The micro-organisms were identified in accordance with standard bacteriologic procedures. Susceptibility testing was carried out using Clinical and Laboratory Standards Institute (CLSI) procedures. RESULTS: Among 77 urine specimens obtained from all recipients during the first month, there were 30 isolated bacterial strains. The most common were Gram-positive bacteria (53.3%) with predominance of enterococci (75%) associated with high levels of aminoglycoside resistant strains (HLAR; 58.3%) and vancomycin-resistant strains (VRE; 25%). Gram-negative bacteria were detected in 46.7% of positive cultures. CONCLUSIONS: In our study, enterococci predominated as 75% of Gram-positive isolates. The increased proportion of multi-drug-resistant bacteria, which can caused severe UTI in patients after SPKT, may be due to the frequent use of prophylaxis of bacterial infections in patients.

Etiologic agents of bacteremia in the early period after simultaneous pancreas-kidney transplantation.

BACKGROUND: Bacteremia is among the known complications in simultaneous pancreas-kidney transplantation (SPKT). This study evaluated the frequency of microbial isolates and their susceptibility profiles among cultures of clinical samples obtained from blood and from the tips of blood vessel catheters of 26 SPKT recipients suspected of bacteremia in the early posttransplant period. PATIENTS AND METHODS: Data on microbiologic blood cultures of 26 adult patients undergoing SPKT were collected prospectively from 2001 to the end of 2006. The isolation and identification of cultured microorganisms were performed according to standard microbiological procedures and commercially available tests. The susceptibility of the strains to antibacterial agents was established by the Clinical and Laboratory Standards Institute guidelines. RESULTS: All patients were followed prospectively for the first 4 weeks after surgery. Among 66 clinical samples, there were 23 microbial isolates from blood samples of 17 recipients and catheter tips of 12 recipients. The most common isolates were Gram-positive bacteria (73.9%) with domination of staphylococci (64.7%) and MRCNS strains (81.8%). Gram-negative bacteria comprised 17.4% of positive cultures, whereas yeast-like fungi, 8.7% with a predominance of Candida glabrata. CONCLUSION: Our study showed predominately Gram-positive bacteria in 73.9% of isolates. The increased proportion of multi-drug-resistant bacteria and fungi to antimicrobial agents may be due to the frequent use of these agents for prophylaxis of bacterial infections in patients.