Trends of Bloodstream Infections in a University Greek Hospital during a Three-Year Period: Incidence of Multidrug-Resistant Bacteria and Seasonality in Gram-negative Predominance

Abstract

The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections' (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011-13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; bla/bla/bla in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried bla, four bla and bla and one bla. A significant increase in monthly BSIs' incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P < 0.001), summer (P < 0.001), and autumn (P < 0.001), as compared to winter months, while Gram-negative bacteria (P < 0.001) and fungi (P < 0.001) were more frequent in summer months. BSIs due to methicillin resistant S. aureus and carbapenem-resistant Gram-negative bacteria increased during the study period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative's BSI.

Bacterial bloodstream infections in level-I trauma intensive care unit in Serbia: incidence, causative agents and outcomes

“…and Pseudomonas spp. This is in line with data from Indian trauma center and ICU of University Greek Hospital [22,33] as well as from invasive isolates recovered in Serbian ICUs reported to Central Asian and Eastern European Surveillance of Antimicrobial Resistance (CAESAR) network in 2016 [34], which suggests reverse trend in causative agents of BSI in ICU and trauma patients in Serbia, from Gram-positive to Gram-negative, possibly due to dissemination of resistant clones of Gram-negative rods in ICU.…”

Antimicrobial resistance of major clinical pathogens in South Korea, May 2016 to April 2017: first one-year report from Kor-GLASS

“…We assessed the relative incidence of BSIs caused by E. coli compared with other species: The relative ratio of E. coli to Sta. aureus in Kor-GLASS was moderate at 2.6, which was lower than the 3.2 observed in Norway [ 10 ], similar to the ratios of 2.4 in Taiwan [ 11 ] and 2.2 in Netherlands [ 12 ], and higher than the ratios of 1.2 in Japan [ 13 ], 1.2 in Vietnam [ 14 ], 1.0 in Greece [ 15 ] and 1.1 in Malawi [ 16 ]. The relative ratio of E. coli to K. pneumoniae in South Korea was also moderate at 2.6, lower than in Northern European countries (5.4 in the Netherlands and 5.0 in Norway), similar to 2.5 in Japan and 3.0 in Taiwan, and higher than 1.0 in Vietnam.…”

Molecular characteristics and predictors of mortality among Gram-positive bacteria isolated from bloodstream infections in critically ill patients during a 5-year period (2012–2016)

“…In the present study, despite the high rate of multi-drug resistant pathogens (86; 61.0%; 10 MRSA, 65 MR-CNS, 11 VRE), 86.5% of patients received appropriate empiric treatment. This high percentage can be explained by the fact that these pathogens are prevalent in the Greek healthcare system, leading to an empiric initiation of anti-Gram-positive antibiotics, such as glycopeptides (vancomycin or teicoplanin), linezolid, or daptomycin in all patients with a severe infection [5]. Glycopeptides were the preferred agent as empiric coverage in our cohort, with only 11 isolates (8.7%) being resistant.…”

“…Due to widespread use of antibiotics, in addition to failing infection control practices, multidrug-resistant Gram-positive cocci are endemic in many countries, including Greece [2,5,6]. Staphylococcus aureus represents the most virulent among Gram-positive cocci and accounts for 9% of BSI in Greece, of which more than 40% were caused by strains resistant to methicillin (MRSA) [5]. MRSA incidence progressively declined from 2000 to 2015 [7].…”