Subgroup analysis of catheter infections (CI).

Group 2.1: CI with matching isolates from blood cultures and the port catheter tip (a). Group 2.2: CI with positive blood culture results and negative culture of the port catheter tip (b). Coagulase-negative staphylococci–CoNS, species–spp.</p

Microbiological spectrum of upper arm port associated infections.

Microbiological spectrum of port pocket infections (a, Group 1) and catheter infections (b, Group 2). Coagulase-negative staphylococci–CoNS, species–spp.</p

Case related data of port explantations.

ObjectivesInfections are common complications in venous access ports. The presented analysis aimed to investigate the incidence, microbiological spectrum, and acquired resistances of pathogens in upper arm port associated infections to provide a decision aid in the choice of therapy.Materials and methodsIn total, 2667 implantations and 608 explantations were performed at a high-volume tertiary medical center between 2015 and 2019. In cases with infectious complications (n = 131, 4.9%), procedural conditions and results of microbiological testing were reviewed retrospectively.ResultsOf 131 port associated infections (median dwell time 103 days, interquartile range 41–260), 49 (37.4%) were port pocket infections (PPI) and 82 (62.6%) were catheter infections (CI). Infectious complications occurred more often after implantation in inpatients compared to outpatients (P Staphylococcus aureus (S. aureus, 48.3%) and coagulase-negative staphylococci (CoNS, 31.0%). Other gram-positive and gram-negative species were encountered in 13.8% and 6.9%, respectively. CI were caused less frequently by S. aureus (8.6%) than CoNS (39.7%). Other gram-positive and gram-negative strains were isolated in 8.6% and 31.0%, respectively. Candida species were seen in 12.1% of CI. An acquired antibiotic resistance was detected in 36.0% of all significant isolates, occurring especially in CoNS (68.3%) and gram-negative species (24.0%).ConclusionsStaphylococci comprised the largest group of pathogens in upper arm port associated infections. However, gram-negative strains and Candida species should also be considered as a cause of infection in CI. Due to the frequent detection of potential biofilm-forming pathogens, port explantation is an important therapeutic measure, especially in severely ill patients. Acquired resistances must be anticipated when choosing an empiric antibiotic treatment.</div

Isolates with distinct susceptibility tests and frequency of strains with acquired resistances in port pocket infections and in catheter infections.

Isolates with distinct susceptibility tests and frequency of strains with acquired resistances in port pocket infections and in catheter infections.</p

Case characteristics of port pocket infections (PPI) and catheter infections (CI).

Case characteristics of port pocket infections (PPI) and catheter infections (CI).</p

Bard Titanium SlimPort^TM.

Fluoroscopic image of a Bard Titanium SlimPortTM with a 6F single lumen polyurethane catheter in typical location at the distal upper arm.</p

Case characteristics of all upper arm port explantations and explantations due to infectious complications.

Case characteristics of all upper arm port explantations and explantations due to infectious complications.</p

Case selection flow chart.

ObjectivesInfections are common complications in venous access ports. The presented analysis aimed to investigate the incidence, microbiological spectrum, and acquired resistances of pathogens in upper arm port associated infections to provide a decision aid in the choice of therapy.Materials and methodsIn total, 2667 implantations and 608 explantations were performed at a high-volume tertiary medical center between 2015 and 2019. In cases with infectious complications (n = 131, 4.9%), procedural conditions and results of microbiological testing were reviewed retrospectively.ResultsOf 131 port associated infections (median dwell time 103 days, interquartile range 41–260), 49 (37.4%) were port pocket infections (PPI) and 82 (62.6%) were catheter infections (CI). Infectious complications occurred more often after implantation in inpatients compared to outpatients (P Staphylococcus aureus (S. aureus, 48.3%) and coagulase-negative staphylococci (CoNS, 31.0%). Other gram-positive and gram-negative species were encountered in 13.8% and 6.9%, respectively. CI were caused less frequently by S. aureus (8.6%) than CoNS (39.7%). Other gram-positive and gram-negative strains were isolated in 8.6% and 31.0%, respectively. Candida species were seen in 12.1% of CI. An acquired antibiotic resistance was detected in 36.0% of all significant isolates, occurring especially in CoNS (68.3%) and gram-negative species (24.0%).ConclusionsStaphylococci comprised the largest group of pathogens in upper arm port associated infections. However, gram-negative strains and Candida species should also be considered as a cause of infection in CI. Due to the frequent detection of potential biofilm-forming pathogens, port explantation is an important therapeutic measure, especially in severely ill patients. Acquired resistances must be anticipated when choosing an empiric antibiotic treatment.</div

Neutrophil recruitment during ALA and effects of selective neutrophil depletion.

<p>(A) Levels of CCL3 mRNA were increased in liver tissue of infected mice (ALA) compared with sham-operated mice (sham) or naïve mice (naïve). (B) Gating strategy to define neutrophils isolated from the abscessed region of the infected liver (abscess), a healthy region from the same liver lobe (healthy tissue), and liver tissue of a naïve mouse (naïve) following intrahepatic amebic infection (n = 3–4 animals/group). Neutrophils were defined as CD11b⁺Ly6G⁺ cells. (C) FACS analysis of blood leukocytes at the indicated time points after neutrophil depletion with anti-Ly6G and anti-GR1 antibodies; control mice were subjected to depletion with a non-specific immunoglobulin (rat IgG). CD11b pre-gated cells were further defined as neutrophils by the expression of Ly6G (n = 5 animals/group) and as blood monocytes by the expression of Ly6C (n = 5 animals/group). Depletion efficacy was estimated on indicated time points after the first treatment. (D) Representative T₂ weighted MRI images of mouse liver tissue showing the size of the abscess (arrowheads) following depletion with anti-Ly6G or anti-GR1 antibodies compared to control mice at the indicated times post-infection. (E) Abscess volume in control mice and anti-Ly6G- and anti-GR1-treated mice. Data represent the mean ± SEM of three independent experiments (n = 9–13); <i>P</i>-values were determined by the unpaired Student's t-test (^*<i>P</i><0.05).</p

ALA formation following depletion of Kupffer cells by clodronate liposomes.

<p>(A) Gating strategy to define resident CD11b⁺F4/80^hi (subset 1) and transient inflammatory CD11b^hiF4/80^lo (subset 2) Kupffer cells in the livers of mice five days after a single intravenous (i.v.) administration of clodronate liposomes (clod) or empty liposomes (ctrl) three days post-infection. Data represent the mean ± SEM of three independent experiments (n = 3 animals/group). (B) Gating strategy to define CD11b⁺CD68⁺ (region 1) and CD11b⁺CD68⁻ (region 2) Kupffer cells following treatment with clodronate liposomes (clod) or empty liposomes (ctrl) three days post-infection. (C) Immunohistochemical staining of liver tissue sections two days post i.v. administration of empty liposomes (ctrl) or clodronate liposomes (clod) using an anti-F4/80 antibody; Kupffer cells are indicated by the brown staining. (D) Gating strategy to define CD11b⁺Ly6G⁻Ly6C⁺ inflammatory monocytes derived from total liver and blood leukocytes five days post-clodronate treatment and three days post-infection. Data represent the mean ± SEM of three independent experiments (n = 3 animals/group). (E) Abscess size in wild-type (WT), clodronate-treated (clod), and control (ctrl) mice was monitored by MRI at the indicated times post-infection. Data represent the mean ± SEM of two experiments (3–4 mice/group). (F) PAS staining of abscessed liver tissue sections from control (ctrl) or clodronate-treated mice three days post-treatment and one day post-infection. Arrows indicate <i>E. histolytica</i> trophozoites. Data represent the mean ± SEM; <i>P</i>-values were determined by the Mann-Whitney U and unpaired Student's t test (^*<i>P</i><0.05).</p