In vitro sensitivity to antibiotics of genital mycoplasmas isolated in Toulouse. Study of new molecules (macrolides and quinolones)]

The minimal metabolism-inhibiting concentrations (MMC) of 11 antibiotics were determined for 40 strains each of M. hominis and U. urealyticum using a terminal color change broth method. All strains were recovered in 1990. Resistance to tetracycline (MMC greater than 8 mg/l) was found for 12.5% of strains of M. hominis and U. urealyticum, as compared with 5% in 1985. Rokitamycin was the most active macrolide against M. hominis (MMC 90: 0.06 mg/l). U. urealyticum strains were susceptible to all the macrolides tested, with the greatest activities being seen for rokitamycin and clarithromycin (MMC 90: 0.06 mg/l and 0.12 mg/l respectively). Sparfloxacin was the most active quinolone against both species. Human clinical trials designed to evaluate these new molecules for the treatment of mycoplasmal and ureaplasmal genital infections are warranted.     

ermA, ermC , tetM and tetK are essential for erythromycin and tetracycline resistance among methicillin-resistant Staphylococcus aureus strains isolated from a tertiary hospital in Malaysia

The objective of this study was to determine the expression and transferability of tetracycline and erythromycin resistance among 188 MRSA strains from a Malaysian tertiary hospital. The minimum inhibitory concentrations (MICs) for oxacillin, erythromycin, tetracycline and ciprofloxacin ranged from 4 to 512 μg/ml, 0.25 to 256 μg/ml, 0.5 to 256 μg/ml and 0.5 to 512 μg/ml, respectively. Tetracycline-resistant strains showed co-resistance towards ciprofloxacin and erythromycin. There was a significant increase (P<0.05) of high-level tetracycline (≥MIC 256 μg/ml) and erythromycin (≥MIC 128 μg/ml) resistant strains in between the years 2003 and 2008. All erythromycin-resistant strains harboured ermA or ermC gene and all tetracycline-resistant strains harboured tetM or tetK gene. The blaZ was detected in all MRSA strains, whereas ermA, tetM, ermC, tetK and msrA genes were detected in 157 (84%), 92 (49%), 40 (21%), 39 (21%) and 4 (2%) MRSA strains, respectively. The blaZ, tetM, ermC and tetK genes were plasmid-encoded, with ermC gene being easily transmissible. Tn5801-like transposon was present in 78 tetM-positive strains. ermA and tetM genes were the most prevalent erythromycin and tetracycline resistance determinants, respectively, in MRSA strains. The association of resistance genes with mobile genetic elements possibly enhances the spread of resistant traits in MRSA.     

In vitro sensitivity to antibiotics in 178 strains of genital mycoplasma isolated from gynecology consultants in Dakar

The susceptibility to antibiotics of 144 strains of Ureaplasma urealyticum and 34 strains of Mycoplasma hominis isolated in Dakar, Senegal, was determinated by MIC determination in a medium. Doxycyclin and minocyclin are active on more than 90% of the strains of U. urealyticum, and more than 80% of M. hominis strains. Over 93% of U. urealyticum strains are susceptible to all the macrolids and apparented tested (erythromycin, pristinamycin, josamycin), but the activity of lincomycin, pristinamycin and josamycin on M. hominis was found only for 70% of the strains. Fluoroquinolones, once adequately studied, could turn out to be a useful alternative in therapeutics.     

In vitro activity of new quinolones against Mycoplasma pathogenic to humans

The in vitro activity of new quinolones was evaluated against Mycoplasma pneumoniae (10 strains) and Mycoplasma hominis (approximately equal to 70 strains) by agar dilution, and against Ureaplasma urealyticum (approximately equal to 115 strains) by broth dilution. The static effect of pefloxacin, ofloxacin, ciprofloxacin, enoxacin was investigated for all the strains. Rosoxacin was included in the tests for U. urealyticum and M. hominis. Pefloxacin, ofloxacin, ciprofloxacin and enoxacin were within the same range of sensitivity for M. pneumoniae; the minimal inhibitory concentrations (MICs) of the 10 strains were 1 mg/l for ciprofloxacin, 2 mg/l for pefloxacin, MICs range was (0.05-1 mg/l) for ofloxacin and (0.5-4 mg/l) for enoxacin. Ciprofloxacin was the most active compound against M. hominis; MICs range and mode MICs were respectively in mg/l: (0.1-1) 0.5 for ciprofloxacin, (0.2-2) 0.5 for ofloxacin, (0.5-2) 1 for pefloxacin, (0.5-8) 2 for enoxacin, (2-16) 2 for rosoxacin. Ofloxacin was the most active compound against U. urealyticum; MICs range and mode MICs were respectively in mg/l: (0.2-2) 1 for ofloxacin, (0.1-8) 2 for rosoxacin, (0.5-8) 4 for pefloxacin, (1-16) 4 for ciprofloxacin, (2-32) 8 for enoxacin. No difference could be observed between tetracycline sensitive or resistant strains.     

Evidence for a reserpine-affected mechanism of resistance to tetracycline in Neisseria gonorrhoeae

The presence of a reserpine-affected mechanism of tetracycline resistance was investigated in 17 Neisseria gonorrhoeae clinical isolates. To establish this fact the MIC of tetracycline in the presence and absence of reserpine was determined, and, in addition, mechanisms of tetracycline resistance were analyzed by PCR. The results showed that reserpine affects the MIC of tetracycline at least 4-fold in all isolates, including those containing the tetM gene. An inhibitory effect of reserpine against the MtrCDE efflux system was ruled out by using strains either with an inactive or with an unrepressed MtrCDE system. The results suggest the presence of a constitutive system of resistance to tetracycline, by a possible efflux pump, which may be inhibited by reserpine. Further studies are required to determine the exact nature of the action of reserpine on the MIC of tetracycline.     

Transferable tetracycline resistance in Listeria monocytogenes from food in Italy

Mechanisms of tetracycline resistance were investigated in two recent Listeria monocytogenes isolates from food, with L. innocua 52P tet(r) as a control. Tetracycline resistance was transferred conjugatively from all three strains to L. ivanovii and from one isolate and the control to Enterococcus faecalis. Molecular analysis demonstrated a chromosomal location for the tet determinant, which was identified as tetM in all cases. These studies are the first to show that L. monocytogenes from food could be a source of tetracycline resistance genes able to spread to other micro-organisms.     

Antibiotic sensitivity of Mycoplasma pathogenic for man

Human pathogen mycoplasmas (Mycoplasma pneumoniae, Mycoplasma hominis, Ureaplasma urealyticum) are intrinsically resistant to antibiotics which inhibit the cell wall biosynthesis (beta-lactams, vancomycin, bacitracin), to polymyxins, rifamycins, sulfonamides, trimethoprim, 5-nitroimidazoles, nitrofurans and to presently available quinolones. These three species are moderately susceptible to aminoglycosides, susceptible to chloramphenicol and highly susceptible to tetracyclines. M. pneumoniae is susceptible to macrolides, lincosamins and streptogramins. M. hominis is resistant to early macrolides (erythromycin, oleandomycin, spiramycin) and susceptible to new macrolides (josamycin, midecamycin, rosaramicin), lincosamins and streptogramins. U. urealyticum is resistant to lincosamins and susceptible to macrolides and streptogramins. Discordant results from various reports can be explained by differences in methods and breakpoint concentration values. In M. pneumoniae species, two strains resistant to macrolides and lincosamins have been described. In M. hominis species, one strain resistant to tetracyclines and another one resistant to tetracyclines and chloramphenicol have been reported. Two to ten percent of U. urealyticum strains are resistant to tetracyclines. These resistances are likely to be plasmid-mediated.     

Epidemiology of tetracycline resistance determinants in Shigella spp. and enteroinvasive Escherichia coli: characterization and dissemination of tet(A)-1

To make a comprehensive study of tetracycline resistance determinant distribution in the genus Shigella, a collection of 577 clinical isolates of Shigella spp. and enteroinvasive Escherichia coli (EIEC) from a variety of geographical locations was screened to identify tetracycline-resistant strains. The 459 tetracycline-resistant isolates identified were then screened by PCR analysis to determine the distribution in these strains of tetracycline efflux resistance determinants belonging to classes A to E, G, and H that have been identified in gram-negative bacteria. Only classes A to D were represented in these strains. Although Tet B was the predominant determinant in all geographical locations, there were geographical and species differences in the distribution of resistance determinants. An allele of tet(A), designated tet(A)-1, was identified and sequenced, and the 8.6-kb plasmid containing determinant Tet A-1, designated pSSTA-1, was found to have homologies to portions of a Salmonella enterica cryptic plasmid and the broad-host-range resistance plasmid RSF1010. This allele and pSSTA-1 were used as epidemiological markers to monitor clonal and horizontal transmission of determinant Tet A-1. An analysis of serotype, distribution of tetracycline resistance determinants, and resistance profiles indicated that both clonal spread and horizontal transfer had contributed to the spread of specific tetracycline resistance determinants in these populations and demonstrated the use of these parameters as an epidemiological tool to follow the transmission of determinants and strains.     

Macrolide-resistance mechanisms in Streptococcus pneumoniae isolates from Chinese children in association with genes of tetM and integrase of conjugative transposons 1545

This study investigated macrolide-resistant Streptococcus pneumoniae carried by Beijing children presenting with respiratory tract infections. Nasopharyngeal S. pneumoniae strains were tested for sensitivity with 15 antibiotics and further analyzed for phenotypes of macrolide-resistant strains and by PCR for the macrolide-resistant genes ermB, mefA, tetM, and integrase of conjugative transposon (Tn1545) intTn. We found 185 strains of S. pneumoniae relatively highly resistant to erythromycin (78.9%), clindamycin (76.2%), tetracycline (86%), and SMZ-TMP (78.7%) but with relatively low resistance to amoxicillin (2.2%), cefaclor (15.5%), ceftriaxone (2.8%), and cefuroxime (14.1%). The 146 strains of erythromycin-resistant S. pneumoniae showed extensive cross-resistance to other macrolides like azithromycin (100%), clarithromycin (100%), acetylspiramycin (95.2%), and clindamycin (95.9%). Genes ermB and mefA were detected in all erythromycin-resistant strains, with ermB(+) 79.5%, ermB + mefA(+) 17.8%, and mefA(+) 2.7%. About 96.9% of tetracycline-resistant isolates were positive for tetM, compared to 26.9% of sensitive strains. Ninety percent of tetracycline-resistant strains were also erythromycin-resistant versus 11.5% of tetracycline-sensitive strains. The intTn gene was present in 87.6% of S. pneumoniae strains and correlated with erythromycin and tetracycline resistance. The close relationship between the conjugative transposon Tn1545 and the genes ermB and tetM is probably one of the important mechanisms explaining the multiple drug resistance of S. pneumoniae.     

桑拿女工人型支原体宫颈感染率及其可能的临床意义

目的调查分析桑拿女工人型支原体宫颈感染率及其可能的临床意义。方法采用女性阴道分泌物革兰染色方法检测阴道毛滴虫、念珠菌和线索细胞,酶联免疫法检测沙眼衣原体,培养法鉴定淋球菌和支原体。结果1030例样本中。人型支原体阳性52例（5％）,其中5例为单独人型支原体定植,而47例（90．4％）为混合菌感染,以解脲脲原体为主（30／52,57．7％）。宫颈炎组与非宫颈炎组人型支原体的感染率差异无统计学意义（χ2=0．51,P〉0．05）。7例人型支原体阳性的宫颈炎病例同时混合感染沙眼衣原体或淋球菌,10例人型支原体阳性的非宫颈炎病例同时伴有念珠菌或阴道毛滴虫感染,或细菌性阴道病。结论无论女性是否患宫颈炎,人型支原体均可以定植于宫颈管,但并不是单独引起宫颈炎的病原体。     

Disseminated tetracycline resistance in oral streptococci: implication of a conjugative transposon

A DNA sequence specifying tetracycline resistance (Tcr) has been previously cloned from a clinical isolate of Streptococcus mutans designated U202 (J. A. Tobian and F. L. Macrina, J. Bacteriol. 152:215-222, 1982). We used this sequence as a molecular probe in studying the dissemination of Tcr among oral streptococcal species isolated from patients treated with tetracycline. Eleven strains (including S. sanguis I, S. sanguis II, S. mitis, and S. salivarius) from seven patients were examined by Southern blot analysis. Seven strains showed strong hybridization to the Tcr probe, two showed weak hybridization, and two did not display detectable hybridization. Based on previous characterization of the cloned sequence, our data suggest the dissemination of the tetM class of resistance determinants among these oral streptococci. One of the clinical S. sanguis I isolates studied was able to transfer its Tcr phenotype to other oral streptococci and to enteric streptococci in the absence of plasmid DNA. This transfer appeared to be conjugation-like on the basis of its insensitivity to DNase and its dependence on intimate cell-to-cell contact. Using the cloned Tcr sequence, we were able to study the progeny of the matings. Our data suggest that this resistance transfer element occupies a chromosomal location in streptococcal cells and that it strongly resembles the conjugative transposon Tn916 in its behavior.     

动物源性和人源性的肠球菌对抗生素耐药性及ermB基因相关性研究

目的 了解大环内酯类耐药基因在人源和动物源性肠球菌之间水平转移的可能性. 方法 采用KB法和琼脂稀释法检测52株动物源性和55株儿科临床分离肠球菌对8种抗生素的敏感性;PCR检测肠球菌的ermB、mefA、tetM、aac(6')/aph(2")基因以及Tn1545的整合酶int基因;PCR扩增联合测序对比人源性和动物源性ermB等位基因的同源性;接合实验研究ermB基因在不同种属、不同来源的肠球菌之间水平转移. 结果 两种来源肠球菌对红霉素的耐药率高达80%以上;ermB是肠球菌对红霉素耐药的主要基因,在人源性和动物源性肠球菌的检出率分别为61.82%(34/55)和53.85%(28/52);已测序菌株中53.0%的北京临床分离株与69.5%的动物分离株携带同一ermB等位基因EF525477;通过接合实验,ermB基因可以在不同来源、不同种属分离株之间进行传递. 结论 动物源性和人源性肠球菌对红霉素和四环素都有高耐药率;滤膜实验证实ermB基因在体外条件下可以在动物源性肠球菌和人源性肠球菌之间传递,但传递频率比较低.动物源性和人源性肠球菌及不同种属的肠球菌有相同ermB等位基因,提示其ermB耐药基因在动物源性和人源性肠球菌水平传递存在的可能性.     

Evaluation of the Mycoplasma Plus and the SIR Mycoplasma kits for quantitative detection and antibiotic susceptibility testing of genital mycoplasma

We compared the results obtained with two commercially available systems (Diagnostics Pasteur) for the quantitative identification and the antibiotic susceptibility testing of the genital mycoplasmas. Ureaplasma urealyticum and Mycoplasma hominis with established methodologies, i.e. isolation on agar with enumeration by dilutions in broth medium and MIC determinations. The Mycoplasma Plus system, consisting of six cups, was designed for the identification and quantitation of genital mycoplasmas and the detection of yeasts. Used in parallel in 150 clinical specimens, it detected U. urealyticum in 42 out of 43 and M. hominis in 10 out of 11 specimens positive by the established methodology. The SIR Mycoplasma antibiogram, consisting of 16 cups, provided for the testing of 1 or 2 concentrations (micrograms/ml) of each of 8 antibiotics: doxycycline, minocycline and lymecycline (4-8); erythromycin (1-4); josamycin (2-8); clindamycin (2); pristinamycin (2); and ofloxacin (1-4). Using an inoculum of about 10(4)-10(5) organisms/ml, we found that major part of the results was in accord with those obtained with the MIC determined in broth for U. urealyticum and on agar for M. hominis. Strains intermediate or resistant to the tetracyclines were identified. Both systems seemed suitable for clinical laboratory use.     

Systematic screening tests for Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum in urogenital specimens of infertile couples

We conducted a prospective study on 100 couples consulting for infertility at the teaching Hospital of Tours, with the scope to determine if there is a benefit for systematic screening of Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum among genito-urinary specimen when exploring couples infertility. C. trachomatis was detected by PCR on sperm, endocervix and urine specimen. M. hominis and U. urealyticum were detected by culture on A7 agar medium and with minigaleries on sperm and endocervix specimen. Standard cultures were also performed on sperm, endocervix, vaginal and urine specimen. Only one specimen (sperm) was positive for C. trachomatis. Three percent of the specimen were positive for U. urealyticum (from which 2,5% of the sperm specimen). No specimen was positive for M. hominis. Our results show that screening of C. trachomatis, M. hominis and U. urealyticum is not systematically required for among check up of infertile couples, given the prevalence of chlamydiosis among the population studied. However, it would be interesting to perform it on a targeted population, according to anamnestic or clinical criteria. In addition, an important modification of vaginal flora was observed in 12% of cases, and 2 vaginosis were diagnosed; the putative consequences of this disequilibrium has to be further investigated.     

Experimental animal infections with Mycoplasma hominis and Ureaplasma urealyticum.

Subcutaneous tissue cavities in mice and guinea pigs were infected with human isolates of Ureaplasma urealyticum and Mycoplasma hominis. The minimal infective dose for M. hominis was as low as less than 10 color-changing units (CCU) for mice and 10(2) CCU for guinea pigs. The minimal infective dose for U. urealyticum was as low as less than 10 CCU for mice and 10(4) CCU for guinea pigs. Mouse infections with either U. urealyticum or M. hominis persisted for 1 day to greater than 4 months. Guinea pigs remained infected for up to 4 weeks. Two M. hominis isolates were similar in their ability to infect subcutaneous tissue cavities but two U. urealyticum isolates varied in their ability to infect the cavities. The histopathology of the M. hominis and U. urealyticum infections was similar: an initial intense polymorphonuclear response with giant cells, followed in 4 weeks by histiocytes and giant cells with some plasma cells and lymphocytes.     

Have Ureaplasma urealyticum and Mycoplasma hominis infections any significant effect on women fertility?

Ureaplasma urealyticum and Mycoplasma hominis are known as sexually transmitted agents. U. urealyticum and M. hominis jeopardize male fertility. However, it is unclear whether these infections significantly contribute to female infertility. In this controlled-study we aimed to establish whether M. hominis and U. urealyticum are risk factors for female fertility and prevalence of infection from these agents in patients attending our infertility clinic. Total 96 married women enrolled in this prospective study; the infertile (study) group consisted of 50 women and fertile (control) group comprised 46 women. The patients were searched about the presence of U. urealyticum and M. hominis by a micro-liquid culture method. The samples were collected from endocervical area with a dacron swab. 28 of 50 (56%) and 18 of 46 (39%) women were evaluated as positive for U. urealyticum culture in the study and control groups respectively. M. hominis was cultured from 4 of 50 (8%) women in the study group as no positive result in controls. There were no statistically significant differences between the groups for both agents (p>0.05), but the higher prevalence of U. urealyticum in infertile women gives emphasis to evaluate these agents in patients that have no any other etiological factor for infertility.     

In vitro activity of nitroxoline on urogenital mycoplasmas

The product nitroxoline was studied in vitro for its activity towards Ureaplasma urealyticum and Mycoplasma hominis. In view of the low MIC values obtained, it seems nitroxoline could be used in the treatment of urinary infections. It is bactericidal, and should not produce resistant strains.     

不孕不育患者解脲脲支原体培养及耐药性分析

目的 研究不孕不育患者解脲脲支原体感染及对药物的耐药性。方法 回顾分析2016年1月~2017年12月在南华大学附属常德医院诊治的94例不孕不育患者和40例已生育健康者的临床资料,对比两组解脲脲支原体感染情况。结果 不孕不育组男性、女性解脲脲支原体感染率分别为13例（30.95%）、21例（40.38%）,高于对照组的2例（12.50%）、4（16.67%）,差异有统计学意义（P<0.05）;94例不孕不育患者共检出68株解脲脲支原体,对解脲脲支原体培养,敏感性较高的为四环素、强力霉素、交沙霉素、美满霉素、克拉霉素、阿奇霉素,耐药性最高的是诺氟沙星。结论 不孕不育患者解脲脲支原体感染率较高可能是不孕不育的主要因素,临床可将其检测作为临床筛查的内容。同时治疗解脲脲支原体感染,应依据药敏试验结果选择敏感性高的抗生素,以提高临床治疗效果。     

Genetic Heterogeneity of Mycoplasma hominis Clinical Isolates Detected during Observation of Patients with Recurrent Urogenital Inflammation

A rapid reproducible effective method for molecular typing of Mycoplasma hominis strains based on random amplified polymorphic DNA (RAPD) technique was developed. RAPD detected genetic heterogeneity of genomes of Mycoplasma hominis clinical isolates and showed changes in the genomes of Mycoplasma hominis clinical isolates from patients with chronic infection.     

A sequence variant of Staphylococcus hominis with a high prevalence of oxacillin and fluoroquinolone resistance.

A newly identified subspecies of Staphylococcus hominis, S. hominis subsp. novobiosepticus, was found to be the cause of several invasive infections at a hospital in New Jersey. This subspecies differs from classical S. hominis, now S. hominis subsp. hominis, by the phenotypic characteristics of novobiocin resistance and the inability to ferment trehalose. DNA sequences of segments of 16S rRNA, DNA gyrase (gyrA), and DNA topoisomerase IV (grlA) genes were determined for the type strains of the 2 subspecies, and for 34 S. hominis clinical isolates. The 16S rRNA sequences of the type strains differed at 3 positions over 410 bp; the grlA sequences differed at 6 positions over 119 bp. These sequence differences define S. hominis subsp. novobiosepticus and S. hominis subsp. hominis "sequevars." Of 34 S. hominis clinical isolates, 31 were S. hominis subsp. novobiosepticus sequevars, 28 of which were resistant to both oxacillin and ciprofloxacin. The clinical microbiology laboratory, using a MicroScan system, identified 7 of the 31S. hominis subsp. novobiosepticus sequevars as S. hominis subsp. hominis on the basis of phenotypic characteristics. Three S. hominis subsp. hominis sequevars were all identified phenotypically as S. hominis subsp. hominis and were oxacillin- and ciprofloxacin-susceptible. Although the precise relationship between the S. hominis sequevars and their phenotypic subspecies remains to be determined, our results indicate that antibiotic-resistant clinical isolates of S. hominis belong almost exclusively to the S. hominis subsp. novobiosepticus sequevar.