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.

Clinical Significance of Gastrointestinal Carriage of Klebsiella Pneumoniae-Producing Extended-Spectrum Beta-Lactamases in Kidney Graft Recipients.

The burden of Klebsiella pneumoniae (KP) producing extended-spectrum beta-lactamases (ESBL+) urinary tract infections (UTIs) is a growing problem after kidney transplantation (KTX). The study was aimed at evaluating the incidence of KP ESBL+ gut colonization in KTX recipients and its correlation with clinical outcomes with special regard to UTIs. The study included all KTX patients hospitalized in our department between January 2014 and December 2016. During this period 2018 KTX patients were admitted: 605 in 2014, 750 in 2015, and 663 in 2016, respectively. Screening for drug-multiresistant Enterobacteriaceae gut carriage was performed in 104 patients (2014), 122 (2015), and 166 (2016). In 2014, 2015, and 2016, 18 (17.3%), 26 (21.3%), and 30 (18.1%) patients had positive test results, and 44 (42.3%), 36 (29.5%), and 45 (27.4%) KTX patients were diagnosed with KP ESBL+ UTI. In 2014, KP ESBL+ UTI was diagnosed in 30 (34.9%) cases with negative anal swab and in 14 patients (77.8%) with positive test result (P = .0008). In 2015, KP ESBL+ UTI was diagnosed in 21 patients (21.9%) with negative anal swab and in 15 (57.7%) with positive test result (P = .0004). In 2016, KP ESBL+ UTI was diagnosed in 24 patients (17.8%) with negative anal swab and in 21 (72.4%) with positive test result (P = .000001). In conclusion, we have revealed a strong association between gut K. pneumoniae colonization, female sex, and MPA intake and KP ESBL+ urinary tract infections in kidney transplant recipients. Our results indicate the very important role of KP ESBL+ screening, while strategies of identified carriers require further research.

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.

Clinical and Microbiological Evaluation of Removable Prosthetic Restorations in Patients Treated With an Organ Transplant.

BACKGROUND: Removable dentures improve function and aesthetics of masticatory organ. Their proper scheme of use and hygiene procedures have an impact on biofilm formation. Microorganisms in biofilm are often resistant to many antibiotics and may pose a potential threat to patients treated with organ transplant. The study provided for evaluation of dental prostheses hygiene standards with reference to staphylococcal microflora in kidney transplant recipients. METHODS: The study involved 62 patients with removable prostheses. Thirty-seven subjects of this group had renal replacement therapy. The other 25 were volunteers with normal renal function. Medical and dental history was collected. Denture hygiene was assessed and swab sampling for microbiological testing were performed on the impression surface of the denture plate. RESULTS: Denture hygiene standards and proper scheme of their use were significantly better in patients of the control group. In both groups, significantly with longer denture use, patient care to provide proper hygiene standards declines. Staphylococcal strains were found in 92% patients of the study group and 84% of the control group, 43% of which were multi-drug resistant strains. No relation was found between patients overall health conditions as well as denture use methods and composition of staphylococcal denture plaque. CONCLUSIONS: Overall health conditions and denture use methods might not have an influence on staphylococcal denture plaque composition. However, the studies conducted did not answer the question of whether the above factors cause quantitative differences. Multidrug-resistant staphylococcal strains inhabiting denture surface may pose a threat to the health of kidney transplant recipients.

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.

Successful Treatment of Urinary Tract Infection in Kidney Transplant Recipients Caused by Multiresistant Klebsiella pneumoniae Producing New Delhi Metallo-Beta-Lactamase (NDM-1) With Strains Genotyping.

BACKGROUND: Klebsiella pneumoniae New Delhi metallo-beta-lactamase-1 (NDM-1) strains have recently become a new threat in kidney transplant recipients due to the strains' resistance to almost all antibiotics, including carbapenems. METHODS: We present a case series of 3 patients with urinary tract infections (UTIs) caused by multiresistant K pneumoniae NDM-1 strains who were treated with the same protocol. Genotyping sequencing with pulsed-field gel electrophoresis was performed in all cases. RESULTS: All patients were male and had undergone kidney transplantation 4, 7, and 8 months, respectively, before the admission. Combined antibiotic therapy consisting of imipenem/cilastatin in maximal doses, gentamicin and/or colistin for 21 to 27 days, followed by oral fosfomycin, was used in all cases. There were no further UTI episodes in 2 patients at the 12-month visit. Three months after initial treatment, the third patient presented with leukocyturia with no clinical symptoms and a urine culture positive for K pneumonia NDM-1 strain. Interestingly, the strain was susceptible to trimethoprim/sulfamethoxazole despite resistance in previous urine culture samples. The patient was successfully treated with trimethoprim/sulfamethoxazole 2 × 960 mg/d for 3 weeks followed by 480 mg/d and 3 doses of fosfomycin. Genotyping sequencing revealed identical DNA restriction fragments in bacterial strains from 2 patients. In the third case, although a difference in 2 restriction fragments was observed, the strain was considered related to the others. CONCLUSIONS: In cases of UTI caused by K pneumoniae NDM-1 strains, prolong combined treatment followed by oral fosfomycin prophylaxis can be successful. Strain genotyping should be performed to optimize further treatment protocols in such cases.

Urinary Tract Infections in Kidney Transplant Recipients Hospitalized at a Transplantation and Nephrology Ward: 1-Year Follow-up.

INTRODUCTION: The aim of this study was to investigate risk factors for urinary tract infections (UTI), the causative organisms of UTI and also their management and treatment. In addition, we evaluated the effects of UTI on renal graft function. METHODS: This analysis included 107 kidney transplant recipients (64% women) with a diagnosis of UTIs confirmed by positive results on urine culture. Type of pathogens, sensitivity to drugs, risk factors for infection, incidence of urosepsis, hospitalization period, treatment methods, and recurrence rates were analyzed. Statistical analysis was performed by using Pearson's χ(2) test, Yates' χ(2) test, the Student t test, Welch's t test, the Mann-Whitney U test, Fisher's exact test, and the Shapiro-Wilk normality test. RESULTS: The most common species isolated from urine samples included Escherichia coli (42%), Klebsiella pneumoniae (15%), and Enterococcus faecalis (10%). The percentage of multidrug-resistant strains was 31%, and urosepsis was diagnosed in 16% of patients. Recurrences developed in 76% of infected patients. Bricker ureterointestinal anastomosis was performed in 11% of patients. Risk factors for severe infections included: pre-transplantation urinary tract surgery (P = .02), double-J stent insertion (more common in men) during KTx (N = 34; 32%), (P = .021), reoperations following transplantation (P = .36), elevated tacrolimus levels at the time of infection (P = .024). Severe infections were diagnosed in patients with lower eGFRs, were associated with a need for longer hospitalization (P = .04) and escalation of antibacterial treatment. Carbapenems were used in 22 patients (20.5%). CONCLUSIONS: UTIs were more common in women, in patients with impaired function of the kidney transplant, and in those with a history of urinary tract interventions. Severe infections were associated with a risk of urosepsis, longer hospitalization, and a need for escalation of antibiotic treatment.

Comparison of Staphylococcal Flora in Denture Plaque and the Surface of the Pharyngeal Mucous Membrane in Kidney Transplant Recipients.

BACKGROUND: Biofilm occurring on removable prostheses is a reservoir of bacterial flora, consisting of both physiological and pathogenic multidrug-resistant microorganisms. Patients undergoing dialysis and organ transplantation are particularly prone to bacterial infections, which can have its source in denture plaque. This study was a comparison of the composition of staphylococcal flora within the surface of the pharyngeal mucous membrane as well as denture plaque in kidney transplant recipients. METHODS: The study included 44 subjects with removable prostheses who reported for a kidney transplant procedure. Swab samples were collected from prostheses and the pharyngeal wall. Isolated strains were identified and investigated for drug resistance. RESULTS: A total of 72 strains of Staphylococcus were isolated from the denture plaque and 53 from the pharynx. In the pharynx, the following species prevailed: Staphylococcus epidermidis, Staphylococcus warneri, and Staphylococcus aureus. The following species prevailed in denture plaque: S epidermidis, S aureus, and Staphylococcus haemolyticus. Among the pharyngeal strains, antibiotic resistance most commonly referred to natural penicillin (77%), constitutive macrolide-lincosamide-streptogramin B resistance (28%), and tetracycline (26.4%). In case of denture plaque, the highest percentage of strains demonstrated resistance to natural penicillin (60%), fosfomycin (32%), and cefoxitin (25%). In 10 subjects (48%), Staphylococcus-induced infections occurred in the first year after transplantation, 5 of which had the same bacterial strain as cultured previously from dentures. CONCLUSIONS: The denture biofilm and surface of the pharynx differ in terms of bacterial composition and bacterial drug resistance profiles. Denture plaque constitutes a considerable reservoir of staphylococcal flora, which can be a potential source of infection in organ transplant recipients.

Influence of Double-J Catheters on Urinary Infections After Kidney Transplantation.

BACKGROUND: One of the most important problem in kidney transplantation is risk of the urinary anastomosis stricture. In uncertain cases the use of a double-J (or JJ) catheter is a standard solution. In case of urinary leak or fistula after the reanastomosis operation, transuretheral JJ implantation is used. A number of patients after JJ use present urinary infection. METHODS: Between 2012 and 2014, 283 kidney transplantations were performed in our center. In 77 cases (27.2%), a JJ was used at the time of operation, in 10 other cases (3.5%) during postoperative period. RESULTS: Urinary infection was observed in 95 patients (33.6%), with Proteus, Klebsiella, Enterobacter, Escherichia, Enterococcus, Pseudomonas, Morganella, and Staphylococcus cultures. In the group of patients without JJ catheters, infections were found in 27.6% of cases and in group with JJ, in 47.1% (46.8% in intraoperative use of catheters and 50% in postoperative curse). CONCLUSIONS: The analysis shows that use of JJ catheters gives urinary infections almost twice more frequent (47.1% vs 27.6%; P = .001) with no difference if the implantation took place during or after the operation.

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.

Bacterial and fungal infections in the early post-transplant period after kidney transplantation: etiological agents and their susceptibility.

BACKGROUND: Infections remain serious complications in solid-organ transplant recipients, despite professional medical care, the introduction of new immunosuppressive drugs, and treatment that decreases the risk of infections. METHODS: The study covered 295 adult patients undergoing kidney transplantation (KTx) between September 2001 and December 2007. All the patients were followed prospectively for infections from the KTx date and during the first 4 weeks after surgery. Samples of clinical materials were investigated for microbiological cultures. The microorganisms were cultured and identified in accordance with standard bacteriological procedures. Susceptibility testing was carried out through the use of Clinical and Laboratory Standards Institute procedures. RESULTS: From 295 KTx recipients, 1073 clinical samples were taken for microbiological examination. Positive cultures were 26.9% (n = 289) of all samples tested; 525 strains were collected. Gram-positive bacteria were isolated in 52.2% (n = 274), Gram-negative bacteria were isolated in 40.8% (n = 214), and fungal strains were isolated in 7% (n = 37). Urine specimens (n = 582) were obtained from 84.5% of 245 recipients during the first month after transplantation. Among the isolated bacterial strains (n = 291), the most common were Gram-negative bacteria (56.4%). Gram-positive bacteria comprised 35.7%; fungal strains were found in 23 cases (7.9%). In surgical site specimens (n = 309), Gram-positive bacteria (72.1%) were the most common. Gram-negative bacteria comprised 24.4%. In blood specimens (n = 138), Gram-positive bacteria (81.6%) were the most common. Gram-negative bacteria comprised 15.8%; fungi were isolated in 2.6%. In respiratory tract specimens (n = 13), among the isolated bacterial strains (n = 8), the most common were Gram-positive bacteria (57.1%). Gram-negative bacteria comprised 14.3%; fungi were isolated in 28.6%. CONCLUSIONS: Urine samples were predominantly positive after KTx. Our study showed Gram-positive bacteria in 52.2% after kidney transplantation. The proportion of isolates of multi-drug-resistant bacterial strains (MRCNS, vancomycin-resistant strains, high-level aminoglycoside-resistant strains, extended-spectrum beta-lactamase producers, and high-level aminoglycoside-resistant strains) was increased. These data indicate the need for strict adherence to infection control procedures in these patients.

Bacterial and fungal infections in the early post-transplantation period after liver transplantation: etiologic agents and their susceptibility.

OBJECTIVE: It has been reported in many studies that one of the main factors influencing morbidity and mortality in patients receiving transplants is infection after transplantation. PATIENTS AND METHODS: The study included 190 adult patients undergoing orthotopic liver transplantation (OLT) between September 2001 and December 2007. All the patients were followed prospectively for infections from the OLT date and during the first 4 weeks after surgery. Immunosuppression consisted of steroids and tacrolimus. Antimicrobial prophylaxis included piperacillin/tazobactam, fluconazole, and selective bowel decontamination (SBD) was performed. Samples of clinical materials were investigated for microbiological cultures. The micro-organisms were cultured and identified in accordance with standard bacteriological procedures. Susceptibility testing was performed using Clinical and Laboratory Standards Institute procedures. RESULTS: From 190 OLT recipients, 2213 clinical samples were obtained for microbiological examination. Positive cultures were found in 27.2% (n = 603) of all samples tested; 1252 strains were collected. Gram-positive bacteria were found in 64.1% (n = 802), Gram-negative bacteria were found in 31.6% (n = 396), and fungal strains were isolated in 4.3% (n = 54). Surgical site specimens (n = 1031) were obtained from 190 recipients during the first month after transplantation. Positive cultures accounted for 29.2% (n = 301) of all samples tested. Among the isolated microbial strains (n = 677), most common were Gram-positive bacteria (73.7%; n = 499). Gram-negative bacteria comprised 25.1% (n = 170). There were fungal strains in 1.2% (n = 8). There were 539 urine specimens. Positive cultures accounted for 16.7% (n = 90) of those. Among the isolated microbial strains (n = 210), most common were Gram-negative bacteria (62.4%; n = 131). Gram-positive bacteria comprised 28.6% (n = 60) and fungi 9% (n = 19). There were 549 blood specimens. Positive cultures were found in 30.6% (n = 168) of all samples tested. Among the isolated microbial strains (n = 263), most common were Gram-positive bacteria in 72.3% (n = 190); Gram-negative bacteria were found in 26.2% (n = 69), and fungal strains were isolated in 1.5% (n = 4). There were 69 respiratory tract specimens. Positive cultures were found in 46.4% (n = 32) of all samples tested. Among the isolated microbial strains (n = 84), most common were Gram-positive bacteria (51.2%; n = 43); Gram-negative bacteria comprised 27.4% (n = 23) and fungi 21.4% (n = 18). CONCLUSIONS: (1) Surgical site samples were predominated samples after LTx. (2) Our study showed Gram-positive bacteria were 64.1% (n = 802), Gram-negative bacteria, 31.6% (n = 396) and fungal strains isolated in 4.3% (n = 54). (3) The increased proportion of isolates of multi-drug-resistant bacterial strains (methicillin resistant coagulase negative Staphylococcus, vancomycin-resistant Enterococcus, high-level aminoglycoside resistance, and extended- spectrum ß-lactamase). (4) These data indicate strict cooperation infection control procedures in these patients.

Bacterial and fungal infections in the early post-transplantation period after simultaneous pancreas-kidney transplantation: etiological agents and their susceptibility.

OBJECTIVE: This study aims to evaluate the frequency of microbial isolates and their susceptibility profiles cultured from clinical samples obtained from 26 simultaneous pancreas-kidney transplant (SPK) recipients suspected of infections during the early post-transplantation period. PATIENTS AND METHODS: Data on microbiologic culture of 26 adult patients undergoing SPK were collected prospectively from 2001 to the end of 2006. Isolation and identification of cultured micro-organisms were 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 guidelines. RESULTS: All the patients were followed prospectively for the first 4 weeks after surgery. In total, 263 samples from clinical materials obtained from 26 SPK recipients were cultured. Bacterial cultures were positive in 29.3% (n = 77) clinical samples. Of these, 219 microbial strains were cultured. Gram-positive bacteria were found in 64% (n = 140), Gram-negative bacteria in 22.8% (n = 50), and fungal strains were isolated in 13.2% (n = 29). Incidence rate values for subsequent isolation of micro-organisms in the sub-periods of time for decreasing the SPK were Gram-positive bacteria (102.3-18.7; I versus IV), growing the Gram-negative bacteria (14-46.1 I versus III) IV were 14, decreasing to fungi (22.1-1.6, I versus IV). Until now this early post-transplantation period was considered homogeneous time after transplantation. This study shows that this period is actually heterogenous, with statistically significant differences being observed between results obtained in consecutive 4 weeks after transplantation. CONCLUSIONS: The results of this study show that the incidence rate was elevated with increasing age in the SPK group of patients. In the SPK group, our data showed the highest rate of isolation of micro-organisms compared with recipients of kidneys or liver.