<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec><h3>Introduction</h3>
<p>A low concentration of ketamine is used to cause an anti-depressive effect. The mechanism of ketamine's action in depression is believed to result, among others, from its anti-inflammatory activity. Despite the fact that only high concentrations of ketamine inhibit bacterial growth, it is clear that even a sub-inhibitory concentration of chemicals may change bacterial properties. Considering the above, in the current study we aimed to evaluate the in vitro influence of ketamine on proliferation of enterococci and their interactions with monocytes.</p>
</sec>
<sec><h3>Materials and Methods</h3>
<p>The studied strains were isolated as etiological agents of infection at Medical University of Gdansk. The proliferation and metabolic activity were determined using the FACSVerse flow cytometer after addition of CFDA-SE to bacterial suspension. For the determination of phagocytosis resistance, THP-1 human monocytes cell line was used. Suspension of monocytes which engulfed CFDA-SE–stained bacteria was then stained with propidium iodide to evaluate cytotoxicity of enterococci.</p>
</sec>
<sec><h3>Results</h3>
<p>The result of the study showed unexpected response of bacterial cells to ketamine at an early stage of culture. In 57.7% of strains, both proliferation rate and metabolic activity were boosted. This group of strains was also less susceptible to phagocytosis than in culture without ketamine. Different response of isolates to ketamine was also visible in changes of proteins’ profile determined by MALDI-TOF.</p>
</sec>
<sec><h3>Conclusions</h3>
<p>The analysis of bacteria at an early stage in the growth curve demonstrated the bacterial diversity in response to ketamine and let us set the hypothesis that microbiome susceptibility to ketamine may be one of the elements which should be taken into consideration when planning the successful pharmacotherapy of depression</p>
</sec>
</abstract>

Introduction
A low concentration of ketamine is used to cause an anti-depressive effect. The mechanism of ketamine's action in depression is believed to result, among others, from its anti-inflammatory activity. Despite the fact that only high concentrations of ketamine inhibit bacterial growth, it is clear that even a sub-inhibitory concentration of chemicals may change bacterial properties. Considering the above, in the current study we aimed to evaluate the in vitro influence of ketamine on proliferation of enterococci and their interactions with monocytes.

Materials and Methods
The studied strains were isolated as etiological agents of infection at Medical University of Gdansk. The proliferation and metabolic activity were determined using the FACSVerse flow cytometer after addition of CFDA-SE to bacterial suspension. For the determination of phagocytosis resistance, THP-1 human monocytes cell line was used. Suspension of monocytes which engulfed CFDA-SE–stained bacteria was then stained with propidium iodide to evaluate cytotoxicity of enterococci.

Results
The result of the study showed unexpected response of bacterial cells to ketamine at an early stage of culture. In 57.7% of strains, both proliferation rate and metabolic activity were boosted. This group of strains was also less susceptible to phagocytosis than in culture without ketamine. Different response of isolates to ketamine was also visible in changes of proteins’ profile determined by MALDI-TOF.

Conclusions
The analysis of bacteria at an early stage in the growth curve demonstrated the bacterial diversity in response to ketamine and let us set the hypothesis that microbiome susceptibility to ketamine may be one of the elements which should be taken into consideration when planning the successful pharmacotherapy of depression

Ketamine used in the therapy of depressive disorders impacts protein profile, proliferation rate, and phagocytosis resistance of enterococci

Department of Medical Microbiology, Faculty of Medicine

Department of Pathology and Experimental Rheumatology, Faculty of Medicine

Department of Psychiatry, Faculty of Medicine

Hospital of the Medical University of Gdansk

Postępy Higieny i Medycyny Doświadczalnej

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Introduction
A low concentration of ketamine is used to cause an anti-depressive effect. The mechanism of ketamine's action in depression is believed to...

Source	Number of strains
Upper respiratory tract	6
Cervical canal	4
Vagina	4
Wound	5
Urine (> 10⁶ cfu/mL)	4
Bedsore	3
Sperm	1

Reference	m/z	Group A	Group A +	Group B	Group B +
Stępień-Pyśniak D	2211	67	88	0	25
	2663	29	0	0	17
	3421	29	29	33	20
	3669	26	35	24	0
	4439	100	100	100	100
	4778	28	37	22	17
	5361	53	40	38	62
	6084	14	16	15	10
	6231	14	15	18	0
	6403	25	24	31	26
	6839	31	32	40	38
	7326	42	59	42	13
	7572	23	0	23	19
	8911	12	15	21	12
	9544	27	35	23	26

Ketamine used in the therapy of depressive disorders impacts protein profile, proliferation rate, and phagocytosis resistance of enterococci

Article Category: Original Study

Data publikacji: 09 sie 2022

Zakres stron: 333 - 338

Otrzymano: 03 sty 2022

Przyjęty: 11 maj 2022

DOI: https://doi.org/10.2478/ahem-2022-0047

Słowa kluczowe
proliferation, phagocytosis resistance, enterococci, ketamine

© 2022 Tomasz Jarzembowski et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Source of strains

Ketamine used in the therapy of depressive disorders impacts protein profile, proliferation rate, and phagocytosis resistance of enterococci

Article Category: Original Study

Data publikacji: 09 sie 2022

Zakres stron: 333 - 338

Otrzymano: 03 sty 2022

Przyjęty: 11 maj 2022

DOI: https://doi.org/10.2478/ahem-2022-0047

Słowa kluczoweproliferation, phagocytosis resistance, enterococci, ketamine

© 2022 Tomasz Jarzembowski et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Source of strains

Słowa kluczowe
proliferation, phagocytosis resistance, enterococci, ketamine