Macrolide Resistance in Mycoplasma pneumoniae, Israel, 2010

Macrolide resistance in Mycoplasma pneumoniae is often found in Asia but is rare elsewhere. We report the emergence of macrolide-resistant M. pneumoniae in Israel and the in vivo evolution of such resistance during the treatment of a 6-year-old boy with pneumonia

Imported Melioidosis, Israel, 2008

In 2008, melioidosis was diagnosed in an agricultural worker from Thailand in the southern Jordan Valley in Israel. He had newly diagnosed diabetes mellitus, fever, multiple abscesses, and osteomyelitis. Burkholderia pseudomallei was isolated from urine and blood. Four of 10 laboratory staff members exposed to the organism received chemoprophylaxis, 3 of whom had adverse events

High-Resolution Melt Curve Analysis for Identification of Single Nucleotide Mutations in the Quinolone Resistance Gene aac(6′)-Ib-cr▿

We have developed a simple PCR-based high-resolution melt curve analysis for identification of the quinolone resistance gene aac(6′)-Ib-cr through regions encompassing the two defining single nucleotide mutations. Dissociation curves showed 100% concordance with DNA sequencing, including the identification of a strain where aac(6′)-Ib and aac(6′)-Ib-cr coexist

Characterization of Biofilm Formation by Clinically Relevant Serotypes of Group A Streptococci

Streptococcus pyogenes (group A streptococcus [GAS]) is a frequent cause of purulent infections in humans. As potentially important aspects of its pathogenicity, GAS was recently shown to aggregate, form intratissue microcolonies, and potentially participate in multispecies biofilms. In this study, we show that GAS in fact forms monospecies biofilms in vitro, and we analyze the basic parameters of S. pyogenes in vitro biofilm formation, using Streptococcus epidermidis as a biofilm-positive control. Of nine clinically important serotype strains, M2, M6, M14, and M18 were found to significantly adhere to coated and uncoated polystyrene surfaces. Fibronectin and collagen types I and IV best supported primary adherence of serotype M2 and M18 strains, respectively, whereas serotype M6 and M14 strains strongly bound to uncoated polystyrene surfaces. Absorption measurements of safranin staining, as well as electron scanning and confocal laser scanning microscopy, documented that primary adherence led to subsequent formation of three-dimensional biofilm structures consisting of up to 46 bacterial layers. Of note, GAS isolates belonging to the same serotype were found to be very heterogeneous in their biofilm-forming behavior. Biofilm formation was equally efficient under static and continuous flow conditions and consisted of the classical three steps, including partial disintegration after long-term incubation. Activity of the SilC signaling peptide as a component of a putative quorum-sensing system was found to influence the biofilm structure and density of serotype M14 and M18 strains. Based on the presented methods and results, standardized analyses of GAS biofilms and their impact on GAS pathogenicity are now feasible

The spread of Mycoplasma pneumoniae is polyclonal in both an endemic setting in France and in an epidemic setting in Israel.

Mycoplasma pneumoniae infections occur both endemically and epidemically, and macrolide resistance has been spreading for 10 years worldwide. A substantial increased incidence of M. pneumoniae infections has been reported in several countries since 2010. Whether this increased incidence is attributed to different or to the same M. pneumoniae genotype is unknown. We have developed a multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) for the molecular typing of M. pneumoniae isolates. In this study, the MLVA typing method was modified and validated to be applicable directly to respiratory tract specimens without culture. This method was applied to 34 M. pneumoniae-positive specimens received at the Bordeaux Hospital, France, between 2007 and 2010 in an endemic setting, and to 63 M. pneumoniae-positive specimens collected during an epidemic surge of M. pneumoniae infections in 2010 in Jerusalem, Israel. The M. pneumoniae endemic spread was shown to be polyclonal in France, with 15 MLVA types identified. Strikingly, the Israeli epidemic surge was also a multi-clonal phenomenon, with 18 circulating MLVA types. The macrolide resistance-associated substitution, A2058G, was found in 22% of the Israeli patients. Macrolide-resistant M. pneumoniae belonged to four MLVA types, the MLVA type Z being the most frequent one. An association between the MLVA type Z and macrolide resistance might exist since macrolide resistance was present or generated during the course of illness in all patients infected with this MLVA type. In conclusion, the discriminatory power of the MLVA showed that the spread of M. pneumoniae strains in France in an endemic setting was polyclonal as well as the surge of M. pneumoniae infections in Israel in 2010

emm Typing of M Nontypeable Invasive Group A Streptococcal Isolates in Israel

We performed emm typing of M nontypeable invasive group A streptococcal (GAS) isolates collected in a prospective population-based study in Israel. One hundred twenty of 131 isolates (92%) had emm sequences compatible with GAS, consisting of 51 different emm types. Eleven isolates were found to be group G streptococcus. Of the 120 isolates, 55 (46%) belonged to 32 types for which there were no typing sera available in the Streptococcal Reference Laboratory in Israel. The other 65 (64%) isolates, consisting of 19 types, had sera available and therefore could have been serotyped. Forty-three isolates had T and emm types which were not correlated according to standard M-typing protocols and were therefore missed. The principal effect of emm typing was the addition of 32 types not previously identified in Israel and the discovery of new associations between emm and T types. emm typing did not significantly change the proportion of M types; the five most common types were 3, 28, 2, 62, and 41. Twenty different types comprised 80% of all isolates. No new emm sequences were discovered. emm typing emphasized the unusually low incidence of M1 strains causing severe disease in Israel. As serological typing of GAS becomes more problematic due to lack of sera and the appearance of new emm types, reference laboratories should replace M typing with emm sequence typing. Development of a GAS vaccine relies on the emm type distributions in different geographical locations. In our study, 7% of isolates (types 41 and 62) are not included in a 26-valent vaccine that is being studied

Characteristics of 34 <i>M. pneumoniae</i>-positive respiratory tract specimens collected at the University Hospital of Bordeaux, France over three years (October 2007–September 2010) and of the corresponding <i>M. pneumoniae</i> isolates grown from them.

a<p>BAL, bronchoalveolar lavage; pleural liq., pleural liquid; NPA, nasopharyngeal aspirate; bronch. asp., bronchial aspirate.</p>b<p>Cycle threshold from the in-house real-time PCR targeting the <i>M. pneumoniae</i> adhesin P1 used for primary detection of the pathogen <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038585#pone.0038585-Touati1" target="_blank">[19]</a>.</p>c<p>wt, wild type; no amp, no amplification with the real-time PCR used for the detection of 23S rRNA mutations associated with macrolide resistance according to Peuchant <i>et</i><i>al.</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038585#pone.0038585-Peuchant1" target="_blank">[21]</a>. Substitution A2059G (<i>E. coli</i> numbering) corresponds to substitution A2064G using <i>M. pneumoniae</i> numbering.</p>d<p>No <i>M. pneumoniae</i> isolate grown from the specimen.</p>e<p>Concurrent specimens from the same patient collected the same day.</p>f<p>Sequential specimens from the same patient.</p>g<p>nd, not determined.</p>h<p>Inconsistencies concerning the marker Mpn1 leading to distinct MLVA types are underlined.</p

Characteristics of 49 <i>M. pneumoniae-</i>positive throat swab specimens collected at the Hadassah-Hebrew University Medical Center, Jerusalem, Israel in 2010, from 41 patients.

a<p>wt, wild type; no amp, no amplification. Nucleotide A2058 (<i>E. coli</i> numbering) corresponds to nucleotide A2063 using <i>M. pneumoniae</i> numbering.</p>b<p>Sequential specimens from the same patient.</p>c<p>A2058A/G: simultaneous finding of both the macrolide-sensitive (2058A) and the macrolide-resistant (2058G) genotypes. (Dual peaks were found in raw data from the sequencing of domain V region of <i>M. pneumoniae</i> 23 S rRNA).</p>d<p>Concurrent specimens from the same patient.</p