- Volume 59, Issue 4, 2010

Congenital sensorineural hearing loss (SNHL) is common. In theWestern world, the incidence is 1–3 per 1000 live births. The aetiologyencompasses genetic and non-genetic factors accounting for 55 %and 45 % of cases, respectively. Reports that describe the contributionof intrauterine infection to the occurrence of congenital SNHL are limited,and comparative analysis of the different pathogens is lacking. Lipopolysaccharide (LPS),a product of bacteriolysis, has been demonstrated to be associated with innerear damage in experimental studies. To elucidate the potential role of thistoxin in congenital SNHL and to identify the pathogenesis and transmissionroutes, we reviewed the literature. We speculate that different routes ofexposure to LPS in utero may result in congenital inner ear damage.

Continuous subculture has been observed to produce changes in the virulenceof micro-organisms, e.g. rabies virus, poliovirus and Mycobacterium bovis BCG. The latter has been used as a vaccine for tuberculosis for thelast 100 years; however, in some instances its efficacy has been observedto be very low. In order to determine whether similar changes can be producedin Mycobacterium tuberculosis, we selected four isolates, M.tuberculosis H37Rv, a Beijing strain (DR-689), and two moreisolates with deletion of the phospholipase C locus (plcA-plcB-plcC), and subjected them to serial culturing on Middlebrook 7H9 medium,with or without ox bile. After 100 passages, we performed RFLP-IS6110 analysis to determine whether genomic changes were produced. We alsochecked their genomic composition by microarray analysis. Changes in virulencewere studied by measuring the cytotoxic effect of parental and subculturedisolates on a THP-1 macrophage monolayer. The most visible change was thechange of position of an IS6110 band of ∼1400 bp to ∼1600 bpin the Beijing isolate subcultured in the ox bile medium. Analysis by microarrayand PCR confirmation did not reveal any genomic changes. Cytotoxic activitywas decreased in the isolates at levels close to that of BCG, and more consistentlyin those subcultured in the presence of ox bile.

Leprosy, a spectral disease manifested on the basis of host immune responses,is complicated by its reactional stages, namely type I reversal reaction (RR)and type II erythema nodosum leprosum (ENL). These reactional stagesare characterized by uncontrolled and aberrant immune responses. Biomarkersfor reactional stages would aid in early diagnosis, efficient treatment, preventionof neurological complications and prediction of predisposition to reactionalstages. In this study, comparative analysis of the serum proteome of leprosypatients by two-dimensional electrophoresis (2DE) followed by massspectrometry showed differential expression of acute-phase protein α 1-acid glycoprotein (AGP; also known as orosomucoid).AGP levels in untreated ENL cases were significantly higher than in lepromatousleprosy (LL; a non-reactional disease stage) (P=0.0126),RR (P=0.0176) and healthy controls (P=0.0030).These data were confirmed using ELISA. The levels of AGP decreased to normallevels after treatment with multidrug therapy and thalidomide (P=0.0167). In a follow-up study, AGP levels, which were highin the untreated ENL stage, decreased significantly at 5 days (P=0.0084) and 21 days (P=0.0027)post-treatment. A stage-dependent increase in AGP in an LL patient who progressedinto the ENL stage was also shown. Glycosylation analysis by 2DE showed differentialexpression of acidic glycoforms of AGP in untreated ENL cases. Changes inAGP concentration and differential expression of isoforms correlated withthe inflammatory condition in ENL and also with the treatment regimen. Thus,initial validation of AGP as an ENL-specific biomarker and treatment indicatorwas shown in this study.

Aspergillus fumigatus is the major cause of invasive aspergillosis (IA),a disease associated with high rates of morbidity and mortality in patientsundergoing treatment for haematological malignancies. This study investigated A. fumigatus growth in vitro and in a murine model of IA inorder to provide insights into the dynamics of extracellular DNA and galactomannan (GM)release and their relevance to early diagnosis of IA. Following inoculationof whole blood with 20 A. fumigatus conidia ml−1,DNA that corresponded to the inoculum could be detected by PCR but GM wasnot detected in plasma separated from the blood sample, indicating that thefungus did not grow in whole blood. The quantities of DNA detected by PCR,and GM, were proportional to the amount of fungal biomass present in vitro. Fungal DNA could be detected in the sera of mice experimentally infectedwith A. fumigatus with maximum detection in cyclophosphamide-treatedmice.

Acute lung injuries due to acute lung infections remain a major cause ofmortality. Thus a combination of an antibiotic and a compound with immunomodulatoryand anti-inflammatory activities can help to overcome acute lung infection-inducedinjuries. Curcumin derived from the rhizome of turmeric has been used fordecades and it exhibits anti-inflammatory, anti-carcinogenic, immunomodulatoryproperties by downregulation of various inflammatory mediators. Keeping theseproperties in mind, we investigated the anti-inflammatory properties of curcuminin a mouse model of acute inflammation by introducing Klebsiella pneumoniae B5055 into BALB/c mice via the intranasal route. Intranasal instillationof bacteria in this mouse model of acute pneumonia-induced inflammation resultedin a significant increase in neutrophil infiltration in the lungs along withincreased production of various inflammatory mediators [i.e. malondialdehyde (MDA),myeloperoxidase (MPO), nitric oxide (NO), tumour necrosisfactor (TNF)-α] in the lung tissue. The animalsthat received curcumin alone orally or in combination with augmentin, 15 daysprior to bacterial instillation into the lungs via the intranasal route, showeda significant (P <0.05) decrease in neutrophil influxinto the lungs and a significant (P <0.05) decreasein the production of MDA, NO, MPO activity and TNF-α levels.Augmentin treatment alone did not decrease the MDA, MPO, NO and TNF-α levels significantly (P >0.05) as compared tothe control group. We therefore conclude that curcumin ameliorates lung inflammationinduced by K. pneumoniae B5055 without significantly (P <0.05) decreasing the bacterial load in the lung tissue whereasaugmentin takes care of bacterial proliferation. Hence, curcumin can be usedas an adjunct therapy along with antibiotics as an anti-inflammatory or animmunomodulatory agent in the case of acute lung infection.

Streptococcus pyogenes is an important human pathogen for whichan association between infection site and selected epidemiological or functionalmarkers has previously been suggested. However, the studies involved oftenused strains with an insufficiently defined clinical background and laboratoryhistory. Thus, the major goal of the present study was to investigate theserelationships in 183 prospectively collected, well-defined, low-passage isolatesfrom a North-East German centre for tertiary care. For each isolate the clinicalbackground (91 respiratory, 71 skin and 21 invasive isolates) andantibiotic-resistance pattern was recorded. All isolates were classified accordingto their emm type, antibiotic-resistance and PFGE pattern (SmaI restriction analysis of genomic DNA). As novel discriminatorymethods we performed a PCR-based typing of the pilus-protein-encoding FCTregion (FCT) and biofilm-formation phenotyping in various culturemedia. Forty-one isolates were found to be resistant to at least one of thetested antibiotics. emm typing revealed emm28, emm12, emm1, emm4, emm89 and emm2 as themost frequent types in our collection. The novel FCT typing showed isolatesencoding FCT types 4 and 2 to be the most common. Overall 113 strains withunique combinations of emm and FCT types, antibiotic-resistance andPFGE patterns were identified. The majority of all isolates revealed an associationof biofilm-formation capacity with growth media. Comparing all results forpotential associations, no correlation could be established between the anatomicalsite of isolation and the emm or the FCT type. There was no relationshipbetween biofilm formation and emm type, antibiotic-resistance orPFGE patterns. However, a novel association between biofilm formation andFCT type became obvious among strains from our collection.

Acanthamoeba keratitis (AK) is a sight-threatening cornealinfection, the epidemiology of which is related to the specific genotype of Acanthamoeba. In this study, the genotypes of 14 Acanthamoebaisolates, each from a patient with AK, were identified according to the highlyvariable DF3 region in the 18S rRNA gene at Shandong Eye Institute, PR China,from 2000 to 2009, and the clinical characteristics of these patients wereanalysed. All 14 amoebae were genotype T4, representing nine different DF3sequence types, seven of which were newly identified. Cornea infestation wasthe main risk factor for these 14 AK patients. Amoebic cysts could be detectedin all corneal scrapes. Corneal ulcers were located mainly at the cornealcentre, accompanied by eye pain, and some appeared with a Wessely ring. Surgerywas carried out on all patients. Acanthamoeba genotypes T4/26and T4/27 were found to cause a more severe keratitis, whilst the othersshowed no significant differences in clinical characteristics. In conclusion,the majority of the keratitis-causing Acanthamoeba isolates weregenotype T4, with Acanthamoeba genotypes T4/26 and T4/27from PR China causing a more severe keratitis.

This study was designed to determine the genetic basis of florfenicol andceftiofur resistance in Escherichia coli isolates recovered fromFrench cattle. In these isolates, ceftiofur resistance was conferred by bla CMY-2 located on three distinct conjugative plasmids ona specific DNA fragment, ISEcp1-bla CMY-2-blc-sugE. Two of the plasmids also carried the floR gene conferringresistance to florfenicol. The floR gene was shown to be associatedwith the insertion sequence ISCR2. Mobile elements appear to contributeto the mobilization of floR and bla CMY-2 genesin E. coli. The presence of bla CMY-2 and floR on the same plasmid highlights the potential risk for a co-selectionof the bla CMY-2 gene through the use of florfenicol infood animal production.

Chronic respiratory infection by Pseudomonas aeruginosa contributessignificantly to the morbidity and mortality associated with cystic fibrosis (CF).Using a series of phenotypic and genotypic tests on collections of 40 isolatesper sputum sample, we analysed fluctuations within sputum populations of the P. aeruginosa Liverpool epidemic strain (LES) during pulmonaryexacerbations. For each of three patients, three sequential sputum sampleswere analysed: (1) on presentation with exacerbation at the RegionalAdult Cystic Fibrosis Unit, Liverpool; (2) a few days into intravenousantibiotic treatment; (3) when the patient had recovered. Fluctuationswere observed in morphotype distribution, the production of virulence-associatedquorum-sensing-dependent exoproducts (the phenazine compound pyocyaninand the elastase LasA), antibiotic susceptibility profiles and levelsof auxotrophy. PCR assays were used to screen isolates for the presence ofnovel regions of the LES genome (islands and prophages) and to detectfree phages. In one patient there was an increase in the prevalence of theLESGI-5 genomic island during the sampling period from 10 to 97.5 %carriage. LES phages 2–4 were detected in either the majority or allsputum samples tested, indicating widespread phage activity during the samplingperiod. The results of this study are indicative that significant fluctuationsoccur within P. aeruginosa populations during short periods of pulmonaryexacerbation and intravenous antibiotic therapy.

Daptomycin is a novel lipopeptide with activity against Gram-positive organismsincluding enterococci. It is licensed for the treatment of Staphylococcusaureus bacteraemia and right-sided endocarditis, but not endocarditisdue to Enterococcus spp. We report a case of enterococcal prostheticvalve endocarditis with an aortic root abscess in an elderly patient who wasnot fit for surgery. The patient's endocarditis relapsed 9 weeks aftera 6 week course of daptomycin.