Tetracycline resistance in Italian Chlamydia suis strains.

In the period from 2004 to 2007, 14 chlamydial isolates were collected from swine with conjunctival and/or reproductive disorders and reared in 4 different farms both in Northern and Southern Italy. The sensitivity of these isolates to doxycycline was tested and compared with the susceptibility to the same drug of the urethral Italian isolate GO86 of C. trachomatis serovar D, the reference strain 6BC of C. psittaci and three isolates of C. abortus, C. pecorum and C. felis, respectively. The C. suis tetracycline resistance (Tcr) phenotype is associated with a resistance gene, tet (C), integrated into the chlamydial chromosome. C. suis isolates were tested for the presence of the tet (C) resistance gene by a PCR assay amplifying a 525 base pair product of the tet (C) gene-coding region. As far as sensitivity to doxycycline is concerned, in comparison to the five strains of C. trachomatis, C. psittaci, C. abortus, C. pecorum and C. felis which were sensitive to doxycycline with MIC and MBC ranging from 0.03 to 0.125 \ub5g/ml, respectively, the MIC and MBC values of doxycycline ranged from 4 to 8 \ub5g/ml, respectively, in most swine isolates tested. All the C. suis isolates carried an identical nucleotide sequence that showed 100 per cent homology with those of the structural gene tet (C)

Chlamydia trachomatis serovar distribution and other concurrent sexually transmitted infections in heterosexual men with urethritis in Italy

The distribution of Chlamydia trachomatis serovars among 157 heterosexual male patients with urethritis and the presence of coinfections with other sexually transmitted infections were studied. One hundred seventeen (74.5%) patients, with a mean age of 33.7 years, were Italians, whereas 40 (25.5%) were immigrants coming from eastern European countries, Africa, and South America. All the immigrants and 82 (70.0%) Italian patients reported sex with prostitutes. Out of 157 patients, 73 (46.5%) were found positive for C. trachomatis in urethral secretions and eight different C. trachomatis serovars were identified. The most common serovars were E (n=18; 24.7%), D (n=15; 20.5%), G (n=14;19.2%), and F (n=12; 16.4%). The sequencing data showed a high degree of conservation of the omp1 gene. Thirty-six (46.7%) out of the 73 C. trachomatis-positive patients were coinfected with another sexually transmitted infection. The most common coinfection was gonorrhoea detected in 22 (30.1%) patients, followed by condyloma in eight (8.2%) patients, syphilis in five (6.8%), and HIV in three (4.1%)

Tetracycline-resistant Chlamydia suis isolates in Italy

Antimicrobials are often used for prophylaxis and therapy of chlamydial infections. The large use of tetracycline has encouraged the selection of resistant organisms. The aim of this study was to evaluate the sensitivity to tetracycline of some Chlamydia suis strains isolated in Italy. The sensitivity of 14 C. suis isolates to doxycycline was tested and compared with the susceptibility to the same drug of the urethral Italian isolate GO86 of C. trachomatis serovar D, the reference strain 6BC of C. psittaci and three isolates of C. abortus, C. pecorum and C. felis, respectively. C. suis isolates were tested for the presence of the tet(C) resistance gene by a PCR assay amplifying a 525 base pair product of the tet(C) gene-coding region. As far as sensitivity to doxycycline is concerned, in comparison to the five strains of C. trachomatis, C. psittaci, C. abortus, C. pecorum and C. felis which were sensitive to doxycycline with MIC and MBC ranging from 0×03 to 0×125 µg/ml, respectively, the MIC and MBC values of doxycycline ranged from 4 to 8 µg/ml, respectively, in most swine isolates tested. All the C. suis isolates carried an identical nucleotide sequence that showed 100 per cent homology with those of the structural gene tet(C) described by Dugan and others (Gene Bank Accession AY428551). None of the other five chlamydial tetracycline sensitive strains carried the resistance gene tet(C)

Sensitivity of Chlamydia spp. to cathelicidin peptides

Several studies have reported an antimicrobial activity of cathelicidin peptides against bacteria, fungi, protozoa. Since chlamydia sensitivity to cathelicidin peptides has not been systematically tested, we comparatively analysed the activity of six cathelicidins against 35 strains of chlamydiae of human and animal origin. The present study shows a different susceptibility of chlamydia species to cathelicidin peptides