Effect of streptomycin treatment on the shedding of and the serologic responses to Leptospira interrogans serovar hardjo subtype hardjobovis in experimentally infected cows

Antibiotic Efficacy in Eliminating Leptospiruria in California Sea Lions (Zalophus californianus) Stranding with Leptospirosis

“…We cannot determine whether the consistent pattern of positive PCR results and negative culture results indicates a true absence of viable leptospires or if it reflects the much lower sensitivity of culture relative to PCR for Leptospira (Ellis, 2015). It is conceivable that genetic material continues to be shed for a period after the infection has been cleared (i.e., all leptospires are killed), but persistent shedding of Leptospira DNA for weeks to months after resolution of the infection seems unlikely and is not supported by the current literature (Gerritsen et al, 1993). In fact, Gerritsen et al (1993) found that Leptospira infected cows treated with antibiotics became PCR-negative 2 d after treatment, while untreated cows remained PCR-positive for at least 70 d. In addition, our findings are consistent with the low sensitivity of culture from urine observed in previous studies of Leptospira infections in other host species.…”

“…It is conceivable that genetic material continues to be shed for a period after the infection has been cleared (i.e., all leptospires are killed), but persistent shedding of Leptospira DNA for weeks to months after resolution of the infection seems unlikely and is not supported by the current literature (Gerritsen et al, 1993). In fact, Gerritsen et al (1993) found that Leptospira infected cows treated with antibiotics became PCR-negative 2 d after treatment, while untreated cows remained PCR-positive for at least 70 d. In addition, our findings are consistent with the low sensitivity of culture from urine observed in previous studies of Leptospira infections in other host species. For example, of urine samples in which Leptospira DNA was detected via PCR, Harkin et al (2003) had no positive cultures out of 42 PCR-positive urine samples; Prager et al (2013) were only able to culture Leptospira from 6 of 32; and Bal et al (1994) were only able to culture Leptospira from 5 of 12.…”

Pharmacokinetics of enrofloxacinHCl‐2H2O (ENRO‐C),PK/PD, and Monte Carlo modeling vs. Leptospiraspp. in cows

“…Testing Enro‐C to treat leptospirosis appears to be desirable based on the clinical efficacy observed for other antibacterial drugs. The existence of a high probability of failure to achieve bacteriological cure with streptomycin, the preference drug to date, has been recognized (Gerritsen, Koopmans, Dekker, De Jong, & Olyhoek, ; Gerritsen, Koopmans, & Olyhoek, ). Other antimicrobial drugs such as amoxicillin (Smith et al., ), oxytetracycline, tilmicosin, and ceftiofur (Alt et al., ) have been tested, in which low efficiencies have been reported and, as indicated above, fluoroquinolones are not particularly effective in the treatment of leptospirosis in veterinary medicine (Griffith et al, ; Mauro & Harkin, ; Wu et al., ).…”

Efficacy of a flexible schedule for administration of a Leptospira borgpetersenii serovar Hardjo bacterin to beef calves

“…As mentioned previously, infections attributable to L borgpetersenii serovar Hardjo are common in herds despite routine vaccination. Investigators in several studies [10][11][12][13][14] found that use of conventional leptospiral vaccines did not provide protection against colonization of the renal or genital tract or transplacental infection after challenge exposure with L borgpetersenii serovar Hardjo, even though the vaccines decreased the frequency of infection and the duration of shedding of the organisms in urine. Cattle were not protected even though vaccination stimulated the development of antibodies against L borgpetersenii serovar Hardjo.…”