Bacterial brothers in arms: cooperation of Staphylococcus aureus and Pseudomonas aeruginosa during antimicrobial exposure

2019 ◽  
Vol 74 (9) ◽  
pp. 2657-2665 ◽  
Author(s):  
Justin R Lenhard ◽  
Nicholas M Smith ◽  
Christine D Quach ◽  
Tuan Q Nguyen ◽  
Linh H Doan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Polymyxin B ◽  
Bacterial Killing ◽  
Small Colony Variant ◽  
Killing Rate ◽  
Small Colony ◽  
Time Kill ◽  
Significant Protective Effect ◽  
Selection Of

Abstract Objectives The optimal selection of antibacterials during polymicrobial infections is poorly defined. The objective of the current investigation was to quantify the pharmacodynamics of relevant antimicrobials during co-culture of Pseudomonas aeruginosa with two separate Staphylococcus aureus phenotypes. Methods Time–kill experiments were conducted against co-cultures of the P. aeruginosa strain PA01 paired with either the normal phenotype (NP) MRSA isolate COL or the small colony variant phenotype (SCVP) MRSA isolate Ia48. The killing by levofloxacin, gentamicin, clindamycin, vancomycin and polymyxin B was evaluated to investigate drugs with activity against one or both pathogens. A Hill-type function and a mechanism-based model were used to describe bacterial killing. Results P. aeruginosa attenuated the activity of clindamycin against NP MRSA, with a reduction in the Emax (maximal killing) from 3.67 (95% CI 2.79–4.56) in monoculture to 1.86 (95% CI 1.35–2.37) during co-culture, whereas a significant protective effect was not observed for other antibacterials. The reduction in NP MRSA killing by clindamycin was described well by a mechanism-based model that generated a maximal killing rate constant of clindamycin against the susceptible NP MRSA subpopulation of 0.267 h−1 in monoculture and 0.0395 h−1 in the presence of P. aeruginosa. During exposure to gentamicin, P. aeruginosa was the dominant organism in co-culture experiments regardless of the drug concentration or S. aureus phenotype; however, the SCVP MRSA was able to dominate the joint population beginning at a levofloxacin concentration of 1.5 mg/L. Conclusions The anti-staphylococcal activity of clindamycin was attenuated by the presence of P. aeruginosa.

scholarly journals Small-Colony Variant Selection as a Survival Strategy for Staphylococcus aureus in the Presence of Pseudomonas aeruginosa

2009 ◽  
Vol 75 (21) ◽  
pp. 6910-6912 ◽  
Author(s):  
Lalitha Biswas ◽  
Raja Biswas ◽  
Martin Schlag ◽  
Ralph Bertram ◽  
Friedrich Götz
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Survival Strategy ◽  
Variant Selection ◽  
Small Colony Variant ◽  
Transport Chain ◽  
Small Colony ◽  
Selection Of

ABSTRACT Previously it has been demonstrated that Staphylococcus aureus is sensitive toward Pseudomonas-secreted exotoxins, which preferentially target the electron transport chain in staphylococci. Here it is shown that a subpopulation of S. aureus survives these respiratory toxins of P seudomonas aeruginosa by selection of the small-colony variant (SCV) phenotype. Purified pyocyanin alone causes the same effect. A hem B mutant of S. aureus survives cocultivation with P. aeruginosa without a decrease in CFU.

scholarly journals In Vitro Activity of the Bacteriophage Endolysin HY-133 against Staphylococcus aureus Small-Colony Variants and Their Corresponding Wild Types

2019 ◽  
Vol 20 (3) ◽  
pp. 716 ◽  
Author(s):  
Nina Schleimer ◽  
Ursula Kaspar ◽  
Dennis Knaack ◽  
Christof von Eiff ◽  
Sonja Molinaro ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Treatment Options ◽  
Nasal Carriage ◽  
Resistance Mechanisms ◽  
Resistance Pattern ◽  
Small Colony Variant ◽  
Small Colony ◽  
Time Kill ◽  
Bacteriophage Endolysin

Nasal carriage of methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) represents both a source and a risk factor for subsequent infections. However, existing MRSA decolonization strategies and antibiotic treatment options are hampered by the duration of administration and particularly by the emergence of resistance. Moreover, beyond classical resistance mechanisms, functional resistance as the formation of the small-colony variant (SCV) phenotype may also impair the course and treatment of S. aureus infections. For the recombinant bacteriophage endolysin HY-133, rapid bactericidal and highly selective in vitro activities against MSSA and MRSA has been shown. In order to assess the in vitro efficacy of HY-133 against the SCV phenotype, minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) were evaluated on clinical SCVs, their isogenic wild types, as well as on genetically derived and gentamicin-selected SCVs. For all strains and growth phases, HY-133 MIC and MBC ranged between 0.12 and 1 mg/L. Time-kill studies revealed a fast-acting bactericidal activity of HY-133 resulting in a ≥3 − log10 decrease in CFU/mL within 1 h compared to oxacillin, which required 4–24 h. Since the mode of action of HY-133 was independent of growth phase, resistance pattern, and phenotype, it is a promising candidate for future S. aureus decolonization strategies comprising rapid activity against phenotypic variants exhibiting functional resistance.

The Study of Bacillus Subtils Antimicrobial Activity on Some of the Pathological Isolates

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Bacterial Growth ◽  
Broad Spectrum ◽  
Inhibitory Activity ◽  
Bacterial Pathogens ◽  
Inhibitory Ability ◽  
Selection Of

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.

scholarly journals Increased Expression of Clumping Factor and Fibronectin-Binding Proteins by hemB Mutants of Staphylococcus aureus Expressing Small Colony Variant Phenotypes

2002 ◽  
Vol 70 (10) ◽  
pp. 5428-5437 ◽  
Author(s):  
Pierre Vaudaux ◽  
Patrice Francois ◽  
Carmelo Bisognano ◽  
William L. Kelley ◽  
Daniel P. Lew ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Surface Display ◽  
Human Embryonic Kidney Cells ◽  
Small Colony Variant ◽  
Reverse Transcription Pcr ◽  
Bacterial Adhesins ◽  
Transport Chain ◽  
Complete Restoration ◽  
Small Colony ◽  
Slow Growing

ABSTRACT Small colony variants (SCVs) of Staphylococcus aureus are slow-growing subpopulations that cause persistent and relapsing infections. The altered phenotype of SCV can arise from defects in menadione or hemin biosynthesis, which disrupt the electron transport chain and decrease ATP concentrations. With SCVs, virulence is altered by a decrease in exotoxin production and susceptibility to various antibiotics, allowing their intracellular survival. The expression of bacterial adhesins by SCVs is poorly documented. We tested fibrinogen- and fibronectin-mediated adhesion of a hemB mutant of S. aureus 8325-4 that is defective for hemin biosynthesis and exhibits a complete SCV phenotype. In this strain, adhesion to fibrinogen and fibronectin was significantly higher than that of its isogenic, normally growing parent and correlated with the increased surface display of these adhesins as assessed by flow cytometry. Real-time quantitative reverse transcription-PCR demonstrated increased expression of clfA and fnb genes by the hemB mutant compared to its isogenic parent. The influence of the hemB mutation on altered adhesin expression was confirmed by showing complete restoration of the wild-type adhesive phenotype in the hemB mutant, either by complementing with intact hemB or by supplementing the growth medium with hemin. Increased surface display of fibrinogen and fibronectin adhesins by the hemB mutation occurred independently from agr, a major regulatory locus of virulence factors in S. aureus. Both agr-positive and agr-lacking hemB mutants were also more efficiently internalized by human embryonic kidney cells than were their isogenic controls, presumably because of increased surface display of their fibronectin adhesins.

SMALL COLONY VARIANT STAPHYLOCOCCUS AUREUS MULTIORGAN INFECTION

2007 ◽  
Vol 26 (3) ◽  
pp. 269-271 ◽  
Author(s):  
Hemant Agarwal ◽  
Rosemary Verrall ◽  
Sudha P. Singh ◽  
Yi-Wei Tang ◽  
Gregory Wilson
Keyword(s):  
Staphylococcus Aureus ◽  
Small Colony Variant ◽  
Small Colony

scholarly journals Choice of sanitary-indicative microorganisms for the assessment of the safety of split-systems

2019 ◽  
Vol 95 (3) ◽  
pp. 296-301
Author(s):  
U. A. Rakhmanin ◽  
S. E. Shibanov ◽  
Sergey V. Kozulya
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
Split Systems ◽  
Air Conditioning Systems ◽  
Cleaning And Disinfection ◽  
Epidemiological Link ◽  
And Staphylococcus Aureus ◽  
Selection Of

Purpose of work is a compilation of data about the microflora which colonizes a split-system, with the aim of selection of sanitary-indicative microorganisms, whose presence in the sample would indicate to the need for cleaning and disinfection of split-systems. Materials and methods. In the article there were used data of five years author’s scientific inquiry, related to the prevention of respiratory diseases, associated with the usage of a local air conditioning systems. We also use the data from the literature. Results. For selection of “indicative” microorganisms, we proposed the usage of nine criteria, each of them have numeric value from 0 to 3 points (risk for health, prevalence rate of the disease, epidemiological link, speed of split system’s colonization, difficulty of cultivation, resistance in the environment, resistance to disinfectants, frequency of detection in home air conditioning systems, frequency of detection in air conditioning systems of public buildings). After the calculation Pseudomonas aeruginosa and Staphylococcus aureus received maximal score (20 points). Therefore, these two types of bacteria are indicative microorganisms. The detection of these microorganisms in split systems will indicate to the contamination of air-conditioning system. This microflora also is a criterion of cleaning and disinfection quality - presence of these microorganisms in the samples after this process will mean that the processing of air conditioning systems was performed poorly. Conclusions. Split systems are very faster colonized by conditionally pathogenic and pathogenic microflora. To prevent the possible hazard for population’s health it is necessary to develop the normative base, according to which sanitary-and-hygienic control over the split-systems working must be carried out. Proposed criteria suggest that Pseudomonas aeruginosa and Staphylococcus aureus are indicative microorganisms, and it’s identification in the air-conditioning system would mean risk for health and necessity for cleaning and disinfection.

scholarly journals A site-directed Staphylococcus aureus hemB mutant is a small-colony variant which persists intracellularly.

1997 ◽  
Vol 179 (15) ◽  
pp. 4706-4712 ◽  
Author(s):  
C von Eiff ◽  
C Heilmann ◽  
R A Proctor ◽  
C Woltz ◽  
G Peters ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Small Colony Variant ◽  
Small Colony ◽  
A Site

Phage Activity Against Planktonic and Biofilm Staphylococcus aureus Periprosthetic Joint Infection Isolates

2021 ◽  
Author(s):  
Katherine M. Caflisch ◽  
Robin Patel
Keyword(s):  
Staphylococcus Aureus ◽  
Successful Treatment ◽  
Periprosthetic Joint Infection ◽  
Joint Infection ◽  
Bacterial Isolates ◽  
Small Colony Variant ◽  
Small Colony ◽  
Planktonic State ◽  
Phage Activity

We recently reported the successful treatment of a case of periprosthetic joint infection (PJI) with phage. Phage activity against bacteria causing PJI has not been systematically evaluated. Here we examined the in vitro activity of seven lytic phages against 122 clinical isolates of Staphylococcus aureus recovered between April 1999 and February 2018 from subjects with PJI. Phages were assessed against planktonic and biofilm phenotypes. Activity of individual phages was demonstrated against up to 73% of bacterial isolates in the planktonic state and up to 100% of biofilms formed by isolates that were planktonically phage-susceptible. Susceptibility to phage was not correlated with small colony variant status. These results demonstrate that phages can infect S. aureus causing PJI in both planktonic and biofilm phenotypes, and thus are worthy of investigation as an alternative or addition to antibiotics in this setting.

Sign in / Sign up

Export Citation Format

Share Document