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Citral modulates virulence factors in methicillin-resistant Staphylococcus aureus. Sci Rep 2021; 11:16482. [PMID: 34389776 PMCID: PMC8363631 DOI: 10.1038/s41598-021-95971-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 07/27/2021] [Indexed: 11/17/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for high morbidity and mortality rates. Citral has been studied in the pharmaceutical industry and has shown antimicrobial activity. This study aimed to analyze the antimicrobial activity of citral in inhibiting biofilm formation and modulating virulence genes, with the ultimate goal of finding a strategy for treating infections caused by MRSA strains. Citral showed antimicrobial activity against MRSA isolates with minimum inhibitory concentration (MIC) values between 5 mg/mL (0.5%) and 40 mg/mL (4%), and minimum bactericidal concentration (MBC) values between 10 mg/mL (1%) and 40 mg/mL (4%). The sub-inhibitory dose was 2.5 mg/mL (0.25%). Citral, in an antibiogram, modulated synergistically, antagonistically, or indifferent to the different antibiotics tested. Prior to evaluating the antibiofilm effects of citral, we classified the bacteria according to their biofilm production capacity. Citral showed greater efficacy in the initial stage, and there was a significant reduction in biofilm formation compared to the mature biofilm. qPCR was used to assess the modulation of virulence factor genes, and icaA underexpression was observed in isolates 20 and 48. For icaD, seg, and sei, an increase was observed in the expression of ATCC 33,591. No significant differences were found for eta and etb. Citral could be used as a supplement to conventional antibiotics for MRSA infections.
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Salerno T, Siqueira AK, Pinto JPDAN, Cunha MDLRDSD, Silvestre PK, Condas LAZ, Lara GHB, Pereira JG, Silva AVD, Listoni FJP, Martins LDSA, Motta RG, Ribeiro MG. Safety issues of raw milk: evaluation of bacteriological and physicochemical characteristics of human milk from a bank in a teaching hospital, focusing on Staphylococcus species. Rev Inst Med Trop Sao Paulo 2021; 63:e54. [PMID: 34231819 PMCID: PMC8266376 DOI: 10.1590/s1678-9946202163054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/22/2021] [Indexed: 11/27/2022] Open
Abstract
Many infants are nurtured with milk supplied by human banks, whose
bacteriological and physical-chemical profiles are a major issue. We
investigated the bacteriological and physical-chemical characteristics, as well
as genotypic and phenotypic and profiles of Staphylococcus
species isolated from 240 samples of breast milk from a bank in a teaching
hospital. Dornic acidity of milk revealed that 95.4% (229/240) had acceptable
limits (< 8.0 oD). Caloric intake showed a wide variation in cream
content (4%), fat (4%) and energy values (559.81 Kcal/L).
Staphylococcus (105/186 or 56.5%) and
Enterobacter (25/186 or 13.4%) were the most prevalent
genera, although other microorganisms were identified, including
Klebsiella pneumoniae and Pseudomonas
aeruginosa. Amoxicillin/clavulanic acid (125/157 or 79.6%),
vancomycin (115/157 or 73.2%), and cephalexin (112/157 or 71.3%) were the most
effective antimicrobials. High resistance rates of isolates were found to
penicillin G (141/157 or 89.8%), ampicillin (135/157 or 86%), and oxacillin
(118/157 or 75.2%). Multidrug resistance to ≥ 3 antimicrobials occurred in 66.2%
(123/186) of the isolates. Residues of microbial multiplication inhibitory
substances were found in 85% (204/240) of samples. Among the
coagulase-positive-CPS and negative-CoNS staphylococci, the
mecA gene was detected in 53.3% (8/15) and 75% (30/40),
respectively. Genes sea, seb and sec were
detected in 20% (3/15) of CPS, while tsst-1 was detected in
13.34% (2/15). In addition, 13.3% (2/15) of S. aureus were
toxin-producers. Genes sea, seb and sec were
detected in 90% (36/40), 5% (2/40) and 15% (6/40) CoNS, respectively.
Enterotoxin production was identified in 5% (2/40) of CoNS. The identification
of multidrug-resistant bacteria, staphylococci species toxin-producers harboring
methicillin-resistance genes, and residues of microbial multiplication
inhibitory substances reinforce the need for a continuous vigilance of milk
quality offered to infant consumption by human banks.
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Affiliation(s)
- Tatiana Salerno
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - Amanda Keller Siqueira
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - José Paes de Almeida Nogueira Pinto
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | | | | | - Larissa Anuska Zeni Condas
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - Gustavo Henrique Batista Lara
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - Juliano Gonçalves Pereira
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - Aristeu Vieira da Silva
- Universidade de Feira de Santana, Departamento de Ciências Biológicas, Feira de Santana, Bahia, Brazil
| | - Fernando José Paganini Listoni
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - Lorrayne de Souza Araújo Martins
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - Rodrigo Garcia Motta
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
| | - Márcio Garcia Ribeiro
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, São Paulo, Brazil
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Molecular characterization of methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolates from human milk samples in Brazil. Braz J Microbiol 2020; 51:1813-1817. [PMID: 32822004 DOI: 10.1007/s42770-020-00367-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/13/2020] [Indexed: 02/06/2023] Open
Abstract
Human milk is the best nutrient for infants. The donor human milk is stored in a milk bank before pasteurization. However, the human milk is not sterile and could be colonized with different types of bacteria. Many studies have shown S. aureus to be the most prevalent potential pathogen detected in human milk. This study characterized 22 methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolates from raw human milk for the presence of virulence genes and agr type. Moreover, the genotypic as identified characterization was realized. The presence of virulence genes sei, seg, sec, seh, and etb was identified in resistant and sensitive strains. We observed the predominance of agr type II. The presence of SCCmec IV (67%, 4/6) and V (33%, 2/6) characterized resistant strains as CA-MRSA. Endemic lineages detected (ST1635/CC5-t002, ST5/CC5-t002, ST72/CC5-t126, ST1/CC1-t127, ST45/CC45-t065, and ST398/t1451) could be related to epidemic clones, such as USA800/ST5, USA700/ST72, USA400/ST1, USA600/ST45, and ST398. This study made it possible to understand the characteristics of virulence and clonality of some strains that circulate in breast milk in our region. The discovery of human milk colonization by MSSA and MRSA strains with molecular characteristics similar to infectious clones spread globally demonstrates the importance of monitoring strains that can spread and cause serious infections.
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