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.

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.