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Cefotaxime-non-susceptibility of Haemophilus influenzae induced by additional amino acid substitutions of G555E and Y557H in altered penicillin-binding protein 3. J Infect Chemother 2019; 25:509-513. [PMID: 30879978 DOI: 10.1016/j.jiac.2019.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/13/2019] [Accepted: 02/18/2019] [Indexed: 11/21/2022]
Abstract
Cefotaxime-non-susceptible Haemophilus influenzae has rarely been isolated from clinical specimens. Although several reports have shown that amino acid (AA) alteration in penicillin-binding protein 3 (PBP3), encoded by the ftsI gene, reduces activity of cefotaxime, precise mechanisms conferring the non-susceptibility have been unclear. We analyzed the ftsI gene of two clinically isolated cefotaxime-non-susceptible H. influenzae strains, 16-11 and 20-07 (minimum inhibitory concentrations [MICs]: 16 and 8 μg/mL, respectively), and found that their deduced AA sequences of PBP3 included two AA substitutions of G555E and Y557H in addition to previously described AA alterations. To clarify whether the two additional substitutions are requisite for cefotaxime non-susceptibility, we produced transformants of Rd KW20 (cefotaxime MIC: ≤0.06 μg/mL) with the ftsI gene of 16-11. Cefotaxime MICs against transformants M1 and M2, of which deduced PBP3s were altered with that of 16-11 entirely and partially (only the N-terminal side up to the AA position 519), were 8 and 0.25 μg/mL, respectively. We also produced M2-555/7 through site-directed mutagenesis inducing additional substitutions of G555E and Y557H into the PBP3 of M2, against which cefotaxime MIC was 8 μg/mL. These findings show that the additional substitutions of G555E and Y557H in PBP3 with previously described alterations cause cefotaxime non-susceptibility. An additional substitution of either G555E or Y557H alone in altered PBP3 reduced cefotaxime activity but the elevation of MICs were within the category of susceptibility. To our knowledge, this is the first study clarifying a genetic factor in the PBP3 causing cefotaxime non-susceptibility among H. influenzae strains.
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Hussain A, Alajmi MF, Khan MA, Pervez SA, Ahmed F, Amir S, Husain FM, Khan MS, Shaik GM, Hassan I, Khan RA, Rehman MT. Biosynthesized Silver Nanoparticle (AgNP) From Pandanus odorifer Leaf Extract Exhibits Anti-metastasis and Anti-biofilm Potentials. Front Microbiol 2019; 10:8. [PMID: 30853939 PMCID: PMC6396724 DOI: 10.3389/fmicb.2019.00008] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 01/07/2019] [Indexed: 12/12/2022] Open
Abstract
Cancer and the associated secondary bacterial infections are leading cause of mortality, due to the paucity of effective drugs. Here, we have synthesized silver nanoparticles (AgNPs) from organic resource and confirmed their anti-cancer and anti-microbial potentials. Microwave irradiation method was employed to synthesize AgNPs using Pandanus odorifer leaf extract. Anti-cancer potential of AgNPs was evaluated by scratch assay on the monolayer of rat basophilic leukemia (RBL) cells, indicating that the synthesized AgNPs inhibit the migration of RBL cells. The synthesized AgNPs showed MIC value of 4-16 μg/mL against both Gram +ve and Gram -ve bacterial strains, exhibiting the anti-microbial potential. Biofilm inhibition was recorded at sub-MIC values against Gram +ve and Gram -ve bacterial strains. Violacein and alginate productions were reduced by 89.6 and 75.6%, respectively at 4 and 8 μg/mL of AgNPs, suggesting anti-quorum sensing activity. Exopolysaccharide production was decreased by 61-79 and 84% for Gram -ve and Gram +ve pathogens respectively. Flagellar driven swarming mobility was also reduced significantly. Furthermore, In vivo study confirmed their tolerability in mice, indicating their clinical perspective. Collective, we claim that the synthesized AgNPs have anti-metastasis as well as anti-microbial activities. Hence, this can be further tested for therapeutic options to treat cancer and secondary bacterial infections.
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Affiliation(s)
- Afzal Hussain
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohamed F Alajmi
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Meraj A Khan
- Program in Translational Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada
| | - Syed A Pervez
- Helmholtz Institute Ulm, Electrochemical Energy Storage, Ulm, Germany
| | - Faheem Ahmed
- Department of Physics, College of Science, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Samira Amir
- Department of Chemistry, College of Science & General Studies, Al Faisal University, Riyadh, Saudi Arabia
| | - Fohad M Husain
- Department of Food Science and Nutrition, College of Food and Agriculture, King Saud University, Riyadh, Saudi Arabia
| | - Mohd S Khan
- Protein Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Gouse M Shaik
- Protein Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Iftekhar Hassan
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Rais A Khan
- Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Md Tabish Rehman
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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Amino Acid Substitution in the Major Multidrug Efflux Transporter Protein AcrB Contributes to Low Susceptibility to Azithromycin in Haemophilus influenzae. Antimicrob Agents Chemother 2017; 61:AAC.01337-17. [PMID: 28848006 DOI: 10.1128/aac.01337-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/10/2017] [Indexed: 11/20/2022] Open
Abstract
Clarithromycin-resistant Haemophilus influenzae strains with a nonsense mutation in acrR generally exhibited susceptibility to azithromycin, although one strain was found to be nonsusceptible; we aimed to clarify the differences. This strain had an amino acid substitution, Arg327Ser, in AcrB. Introduction of this substitution into H. influenzae Rd caused an increase in the MIC of azithromycin, suggesting that this substitution contributed to nonsusceptibility. These findings indicate that azithromycin-nonsusceptible isolates could occur through stepwise mutation in the acr region.
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Kiyasu Y, Akiyama D, Kurihara Y, Koganemaru H, Hitomi S. Pericarditis caused by Campylobacter fetus subspecies fetus associated with ingestion of raw beef liver. J Infect Chemother 2017; 23:833-836. [PMID: 28803866 DOI: 10.1016/j.jiac.2017.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/08/2017] [Accepted: 07/22/2017] [Indexed: 02/04/2023]
Abstract
Campylobacter fetus is an organism residing primarily in the gastrointestinal tracts of cattle and sheep and transmitting to humans through ingestion of contaminated food products or surface water. The organism has caused various extraintestinal infections but, to date, purulent pericarditis due to the organism has rarely been described. We report a case of purulent pericarditis due to C. fetus subsp. fetus, occurring in a patient having several predisposing conditions, including receiving hemodialysis therapy, recent surgery for cecal cancer, and administration of esomeprazole. The patient mentioned having eaten homemade raw beef liver two weeks before the onset, suggesting that the ingested food product was contaminated with C. fetus and the organism transmitted to the pericardium through the bloodstream although blood culture was negative. The causative organism, recovered from the pericardial effusion, was unidentifiable with commercial systems but determinable with molecular methods at the subspecies level. The patient fully improved with pericardiocentesis and subsequent administration of ciprofloxacin, to which the organism was considered susceptible, for a total of four weeks. This is the first case of C. fetus pericarditis in which a history of ingesting a raw food product was clearly mentioned.
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Affiliation(s)
| | - Daiki Akiyama
- Department of Emergency and Critical Care Medicine, University of Tsukuba Hospital, Japan
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Seyama S, Wajima T, Nakaminami H, Noguchi N. Clarithromycin Resistance Mechanisms of Epidemic β-Lactamase-Nonproducing Ampicillin-Resistant Haemophilus influenzae Strains in Japan. Antimicrob Agents Chemother 2016; 60:3207-10. [PMID: 26953210 PMCID: PMC4862528 DOI: 10.1128/aac.00163-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 02/29/2016] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to clarify the clarithromycin resistance mechanisms of β-lactamase-nonproducing ampicillin-resistant Haemophilus influenzae strains. In all clarithromycin-resistant strains, the transcript level of acrB was significantly elevated, and these strains had a frameshift mutation in acrR Introduction of the acrR mutation into H. influenzae Rd generated a clarithromycin-resistant transformant with the same MIC as the donor strain. Our results indicate that the acrR mutation confers clarithromycin resistance by the increasing the transcription of acrB.
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Affiliation(s)
- Shoji Seyama
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Takeaki Wajima
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Hidemasa Nakaminami
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Norihisa Noguchi
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
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