Bacteriostatic and Bactericidal Effect of Tigecycline on Leptospira spp.

Abstract

Tigecycline is a relatively new antimicrobial, belonging to glycylcyclines with antimicrobial activity against a large spectrum of bacteria. Very few data are available on its effect on Leptospira spp., which consist in a bacteriostatic mechanism. The aim of this investigation was to evaluate the bacteriostatic and bactericidal effect of tigecycline on reference Leptospira strains belonging to 16 serovars. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined through the microdilutions method, and tetracycline was used as the control. Results showed that tigecycline had higher MIC and MBC values than tetracycline. Obtained MIC values were between 4 and 32 µg/mL, while MBC values between 16 and >128 µg/mL. Patoc (MIC: 4 µg/mL; MBC: 16 µg/mL) resulted in the most susceptible serovar, while the most resistant were Bataviae (MIC: 32 µg/mL; MBC: 64 µg/mL), Bratislava (MIC: 8 µg/mL; MBC 128 µg/mL), and Tarassovi (MIC: 8 µg/mL; MBC: >128 µg/mL). This is the first investigation focused on the effect of tigecycline against Leptospira spp. reference strains. Since tigecycline is used as a treatment for bacteremia and urinary tract disease, and these symptoms could be linked to Leptospira infection, the possibility of using this antibiotic as a treatment for leptospirosis should be evaluated. Further studies are needed to explore the possibility to use tigecycline for in vivo application against Leptospira.

Leptospirosis-Induced Myocarditis and Arrhythmias

“…Recent evidence shows that tigecycline possesses both in vivo bacteriostatic and bactericidal effects on Leptospira strains. 31 Despite it being associated with increased mortality among intensive care unit patients, the multidisciplinary team opted for a synergistic combination as the patient spiraled down further. 32 , 33 …”

Preliminary Evaluation of In Vitro Bacteriostatic and Bactericidal Effect of Salt on Leptospira spp.

“…Sterile NaCl was added to EMJH medium in order to reach a stock solution with 21.05% of salt; this allowed to start to test a concentration of 20% of NaCl, considering the inoculum addition, as reported below. The minimum inhibitory concentration (MIC) determination was performed by the broth microdilution method, as previously reported [ 37 , 38 ]. Leptospira cultures were quantified with spectrophotometry using optical density at 420 nm (Multiskan™ FC Microplate Photometer; Thermo Fisher Scientific, Haverhill, MA, USA) to reach a concentration which corresponds approximately to 1.5 × 10 8 cfu/mL: considering that an OD ranging between 0.052 to 0.1 corresponds to approximately 2–3 × 10 8 leptospires per mL, cultures were diluted in EMJH to reach this OD, using EMJH as blank; after, standardized culture was diluted 1:2 in EMJH to reach the desired inoculum concentration [ 39 , 40 ].…”

“…Leptospira cultures were quantified with spectrophotometry using optical density at 420 nm (Multiskan™ FC Microplate Photometer; Thermo Fisher Scientific, Haverhill, MA, USA) to reach a concentration which corresponds approximately to 1.5 × 10 8 cfu/mL: considering that an OD ranging between 0.052 to 0.1 corresponds to approximately 2–3 × 10 8 leptospires per mL, cultures were diluted in EMJH to reach this OD, using EMJH as blank; after, standardized culture was diluted 1:2 in EMJH to reach the desired inoculum concentration [ 39 , 40 ]. The procedure to assess the MIC and minimum bactericidal concentration (MBC) is the same previously reported [ 37 ]. In detail, in each well of the 96-well plates, two-fold serial dilutions were performed in EMJH/salt medium, ranging from a 20% to 0.03% salt concentration.…”

High-throughput sequencing technologies in the detection of livestock pathogens, diagnosis, and zoonotic surveillance

“… Disease Pathogen Route of infection Antibiotic resistance genes Transfer source References Bovine tuberculosis Mycobacterium bovis, Mycobacterium tuberculosis Drinking infected milk, inhaling the bacterium shed by infected animals, or direct bacterial contact with a cut or other breaks in the skin pncA, embB, katG, inhA, rpoB, rrs, gyrA, gyrB Respiratory secretions, feces, milk [120] , [121] , [122] , [123] , [124] Salmonellosis Salmonella sp. Gastroenteritis mcr-1 ESBL-CTX-M-1, ESBL-CTX-M-2, ESBL-CTX-M-9 ESBL-CTX-M-15 ESBL-CTX-M-65, ESBL-TEM-52, CMY-2, CipR Pork products, poultry, seafood, milk, chicken, eggs [120] , [121] Leptospirosis Leptospira interrogans Skin or mucous membranes (eyes, nose, or mouth), especially if the skin is broken from a cut or scratch rpsL, rrs Contaminated water, animal urine, contaminated food [120] , [125] Foodborne disease Escherichia coli Contaminated water, contaminated food, oral-fecal route ESBL, ESBL-CTX-M-1, ESBL-CTX-M-9, TEM-52, CMY-2-AmpC, aadA12, aadA13, aadA7 Livestock, water, person-to-person [121] Enterobacteriaceae bla CTX_M , bla TEM,, bla SHV, bla OXA-10, bla OXA-13, bla CMY, bla LAT, bla ACC, bla ACT, bla MIR-1, bla DHA [126] , [127] , [128] , [129] , [130] Bumblefoot / foodborne disease Staphylococcus aureus skin and mucous mecA, mecB, mecC, mecD infected blood or body fluids …”