The effects of some antibiotics on polymorphonuclear leukocyte functions of elderly patients in vitro before and after zinc supplementation

Intracellular Penetration and Effects of Antibiotics on Staphylococcus aureus Inside Human Neutrophils: A Comprehensive Review

Neutrophils are important assets in defense against invading bacteria like staphylococci. However, (dysfunctioning) neutrophils can also serve as reservoir for pathogens that are able to survive inside the cellular environment. Staphylococcus aureus is a notorious facultative intracellular pathogen. Most vulnerable for neutrophil dysfunction and intracellular infection are immune-deficient patients or, as has recently been described, severely injured patients. These dysfunctional neutrophils can become hide-out spots or “Trojan horses” for S. aureus. This location offers protection to bacteria from most antibiotics and allows transportation of bacteria throughout the body inside moving neutrophils. When neutrophils die, these bacteria are released at different locations. In this review, we therefore focus on the capacity of several groups of antibiotics to enter human neutrophils, kill intracellular S. aureus and affect neutrophil function. We provide an overview of intracellular capacity of available antibiotics to aid in clinical decision making. In conclusion, quinolones, rifamycins and sulfamethoxazole-trimethoprim seem very effective against intracellular S. aureus in human neutrophils. Oxazolidinones, macrolides and lincosamides also exert intracellular antibiotic activity. Despite that the reviewed data are predominantly of in vitro origin, these findings should be taken into account when intracellular infection is suspected, as can be the case in severely injured patients.

Establishment of a method for measuring leukocyte phagocytosis based on 16S rDNA

The goal of this study was to develop a method for measuring leukocyte phagocytosis based on 16S rDNA, and to investigate its clinical significance. Whole blood was collected and incubated with bacteria. Free bacteria were removed using differential centrifugation. Bacteria phagocytosed by leukocytes were measured using real-time PCR technology based on universal primers of 16S rDNA. The change rate of bacterial DNA (CRD) was considered as a criterion of phagocyte function. In the test, the CRD of whole blood leukocytes from a healthy volunteer was repeatedly measured (five times) by the new method in order to document the repeatability. The CRD from the new method and the rate of phagocytosis measured using traditional microscopy were compared in a young healthy group and an aged group of volunteers to observe the relationship between the new method and traditional microscopy and to assess the clinical value of the new method. There was a significant correlation between real-time PCR technology and traditional microscopy (r = 0.82, P < 0.01). The coefficient of variation (CV) was 2.7% for the new method. The CRD was statistically significantly lower in the aged group than in the healthy young group (P < 0.05). The real-time PCR method established for measuring leukocyte phagocytosis was accurate and reliable, and has potential clinical application.

The effects of zinc supplementation on wound healing and metabolic status in patients with diabetic foot ulcer: A randomized, double-blind, placebo-controlled trial

This study was performed to determine the effects of zinc supplementation on wound healing and metabolic status in patients with diabetic foot ulcer. The current randomized, double-blind, placebo-controlled trial was conducted among 60 patients (aged 40-85 years old) with grade 3 diabetic foot ulcer. Participants were randomly divided into two groups (30 participants in each group) to take either 220 mg zinc sulfate supplements containing 50 mg elemental zinc or placebo daily for 12 weeks. After the 12-week intervention, compared with the placebo, zinc supplementation was associated with significant reductions in ulcer length (-1.5 ± 0.7 vs. -0.9 ± 1.2 cm, p = 0.02) and width (-1.4 ± 0.8 vs. -0.8 ± 1.0 cm, p = 0.02). In addition, changes in fasting plasma glucose (-40.5 ± 71.0 vs. -3.9 ± 48.5 mg/dl, p = 0.02), serum insulin concentration (-8.0 ± 15.4 vs. +1.1 ± 10.3 µIU/ml, p = 0.009), homeostasis model of assessment-estimated insulin resistance (-3.9 ± 7.1 vs. +0.8 ± 5.9, p = 0.007), the quantitative insulin sensitivity check index (+0.01 ± 0.03 vs. -0.002 ± 0.02, p = 0.04) and HbA1c (-0.5 ± 0.8 vs. -0.1 ± 0.5%, p = 0.01) in the supplemented group were significantly different from the changes in these indicators in the placebo group. Additionally, significant increases in serum HDL-cholesterol (+4.1 ± 4.3 vs. +1.1 ± 5.1 mg/dl, p = 0.01), plasma total antioxidant capacity (+91.7 ± 213.9 vs. -111.9 ± 188.7 mmol/L, p < 0.01) and total glutathione (+68.1 ± 140.8 vs. -35.0 ± 136.1 µmol/L, p = 0.006), and significant decreases in high sensitivity C-reactive protein (-20.4 ± 24.6 vs. -6.8 ± 21.3 µg/ml, p = 0.02) and plasma malondialdehyde concentrations (-0.6 ± 0.9 vs. -0.2 ± 0.7 µmol/L, p = 0.03) were seen following supplementation with zinc compared with the placebo. Zinc supplementation for 12 weeks among diabetic foot ulcer patients had beneficial effects on parameters of ulcer size and metabolic profiles.

Key Roles of Human Polymorphonuclear Cells and Ciprofloxacin in Lactobacillus Species Infection Control

Lactobacilli have the potential to act as reservoirs of antibiotic resistance genes similar to those found in human pathogens, with the risk of transferring these genes to many pathogenic bacteria. In this study, we investigated the role of human polymorphonuclear cells (PMNs) against Lactobacillus spp. both resistant and susceptible to ciprofloxacin (a fluoroquinolone) and the effect of ciprofloxacin on the interaction between PMNs and three Lactobacillus spp. with different patterns of susceptibility to this drug. Hence, the primary functions of PMNs, such as phagocytosis and bacterial intracellular killing, against lactobacilli were investigated. The rate of PMN phagocytosis was high for ciprofloxacin-sensitive and ciprofloxacin-resistant strains. The patterns of intracellular killing of ciprofloxacin-sensitive and ciprofloxacin-resistant strains by PMNs underline that PMNs alone were able to kill lactobacilli. The addition of ciprofloxacin to PMNs did not result in a significant increase in the bacterial uptake by phagocytes. On the contrary, ciprofloxacin had a marked effect on PMN intracellular killing, resulting in increased numbers of killed ciprofloxacin-sensitive bacteria in comparison with antibiotic-free controls. Our data show that by itself, the profile of antibiotic resistance does not constitute an intrinsic factor of greater or lesser pathogenicity toward the host. The ability of PMNs to kill a diverse array of bacterial pathogens is essential for human innate host defense, primarily in immunocompromised patients.

Association of complement C3 and interleukin-1 with foot infections in diabetic patients

The study of the bacteriological profile, the association of complement C3, interleukin-1beta, and zinc therapy of diabetic foot ulcers (type two) was investigated. Twenty diabetics without foot ulcers (group I), 50 diabetics with foot ulcers (group II), and 10 matched normal controls (group III) were enrolled in this study. Diabetic foot ulcers were mostly of grade 2. The most frequent organisms were Clostridium spp., Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, respectively. Vancomycin, Imipenem, and Meropenem were the most effective against Gram-positive and Gram-negative aerobes, while Imipenem, Meropenem and Chloramphenicol for Gram-positive anaerobes. Group II had abnormal levels of C3 (72%). A significant higher concentration of C3 was found in group II. Group II had abnormal levels of IL-1β (60%). A significant higher concentration of IL-1β was found in group II. Zinc therapy (25 mg/day/oral) induced a highly significant decrease in the frequency of Gram-positive anaerobes and levels of IL-1β. Significantly increases all mineral concentrations in serum level except Mn(+2). The study highlights the prevalence of antibiotic multi-drug resistant bacteria causing foot infections in diabetics which require combined antimicrobial therapy. Altered levels of serum complement C3 and IL-1β might be responsible for depressed immune response which might be causes for delayed wound healing and repeated infections. Zinc supplementation may help in healing the wounds by enhancing the immune response.

Reactive oxygen intermediate-induced pathomechanisms contribute to immunosenescence, chronic inflammation and autoimmunity

Deregulation of reactive oxygen intermediates (ROI) resulting in either too high or too low concentrations are commonly recognized to be at least in part responsible for many changes associated with aging. This article reviews ROI-dependent mechanisms critically contributing to the decline of immune function during physiologic - or premature - aging. While ROI serve important effector functions in cellular metabolism, signalling and host defence, their fine-tuned generation declines over time, and ROI-mediated damage to several cellular components and/or signalling deviations become increasingly prevalent. Although distinct ROI-associated pathomechanisms contribute to immunosenescence of the innate and adaptive immune system, mutual amplification of dysfunctions may often result in hyporesponsiveness and immunodeficiency, or in chronic inflammation with hyperresponsiveness/deregulation, or both. In this context, we point out how imbalanced ROI contribute ambiguously to driving immunosenescence, chronic inflammation and autoimmunity. Although ROI may offer a distinct potential for therapeutic targeting along with the charming opportunity to rescue from deleterious processes of aging and chronic inflammatory diseases, such modifications, owing to the complexity of metabolic interactions, may carry a marked risk of unforeseen side effects.

Synthesis, structural characterization and influence on the phagocytic activity of human neutrophils of thiazoline and thiazine derivative ligands and their zinc(II) complexes

The zinc(II) complexes dichloro[2-(3,4-dichlorophenyl)imino-kappaN-(2-thiazolin-kappaN-2-yl)thiazolidine]zinc(II) (1) and dichloro[2-(3,4-dichlorophenyl)imino-kappaN-(4H-5,6-dihydro-1,3-thiazin-kappaN-2-yl)tetrahydrothiazine]zinc(II) (2) have been isolated and characterized in the solid state by X-ray diffraction, elemental analysis and IR spectra. In both complexes, the environment around the zinc(II) ion may be described as a distorted tetrahedral geometry, with the metallic atom coordinated to two chlorine atoms [Zn-Cl(1)=2.218(1)A; Zn-Cl(2)=2.221(1)A], one imino nitrogen [Zn-N(3)=2.042(2)A] and one thiazoline nitrogen [Zn-N(1)=2.022(2)A] in complex 1 and to two chlorine atoms [Zn-Cl(1)=2.216(1)A; Zn-Cl(2)=2.192(1)A], one imino nitrogen [Zn-N(3)=2.045(2)A] and one thiazine nitrogen [Zn-N(1)=2.039(2)A] in complex 2. In addition, we also report in this study the crystal structure of the 2-(3,4-dichlorophenyl)imino-N-(2-thiazolin-2-yl)thiazolidine (TdTn) ligand as well as the synthesis and characterization by X-ray diffraction, (1)H and (13)C NMR spectra, elemental analysis, IR and electronic spectra of the 2-(3,4-dichlorophenyl)imino-N-(4H-5,6-dihydro-1,3-thiazin-2-yl)tetrahydrothiazine (TzTz) ligand. Besides, we study the phagocytic function in humans neutrophils treated with each complex and ligand aforementioned.