Genotypic Evolution of Klebsiella pneumoniae Sequence Type 512 during Ceftazidime/Avibactam, Meropenem/Vaborbactam, and Cefiderocol Treatment, Italy

In February 2022, a critically ill patient colonized with a carbapenem-resistant K. pneumoniae producing KPC-3 and VIM-1 carbapenemases was hospitalized for SARS-CoV-2 in the intensive care unit of Policlinico Umberto I hospital in Rome, Italy. During 95 days of hospitalization, ceftazidime/avibactam, meropenem/vaborbactam, and cefiderocol were administered consecutively to treat 3 respiratory tract infections sustained by different bacterial agents. Those therapies altered the resistome of K. pneumoniae sequence type 512 colonizing or infecting the patient during the hospitalization period. In vivo evolution of the K. pneumoniae sequence type 512 resistome occurred through plasmid loss, outer membrane porin alteration, and a nonsense mutation in the cirA siderophore gene, resulting in high levels of cefiderocol resistance. Cross-selection can occur between K. pneumoniae and treatments prescribed for other infective agents. K. pneumoniae can stably colonize a patient, and antimicrobial-selective pressure can promote progressive K. pneumoniae resistome evolution, indicating a substantial public health threat.

Genetic background of neomycin resistance in clinical Escherichia coli isolated from Danish pig farms

Neomycin is the first-choice antibiotic for the treatment of porcine enteritis caused by enterotoxigenic Escherichia coli. Resistance to this aminoglycoside is on the rise after the increased use of neomycin due to the ban on zinc oxide. We identified the neomycin resistance determinants and plasmid contents in a historical collection of 128 neomycin-resistant clinical E. coli isolates from Danish pig farms. All isolates were characterized by whole-genome sequencing and antimicrobial susceptibility testing, followed by conjugation experiments and long-read sequencing of eight selected representative strains. We detected 35 sequence types (STs) with ST100 being the most prevalent lineage (38.3%). Neomycin resistance was associated with two resistance genes, namely aph(3')-Ia and aph(3')-Ib, which were identified in 93% and 7% of the isolates, respectively. The aph(3')-Ia was found on different large conjugative plasmids belonging to IncI1α, which was present in 67.2% of the strains, on IncHI1, IncHI2, and IncN, as well as on a multicopy ColRNAI plasmid. All these plasmids except ColRNAI carried genes encoding resistance to other antimicrobials or heavy metals, highlighting the risk of co-selection. The aph(3')-Ib gene occurred on a 19 kb chimeric, mobilizable plasmid that contained elements tracing back its origin to distantly related genera. While aph(3')-Ia was flanked by either Tn903 or Tn4352 derivatives, no clear association was observed between aph(3')-Ib and mobile genetic elements. In conclusion, the spread of neomycin resistance in porcine clinical E. coli is driven by two resistance determinants located on distinct plasmid scaffolds circulating within a highly diverse population dominated by ST100. IMPORTANCE Neomycin is the first-choice antibiotic for the management of Escherichia coli enteritis in pigs. This work shows that aph(3')-Ia and to a lesser extent aph(3')-Ib are responsible for the spread of neomycin resistance that has been recently observed among pig clinical isolates and elucidates the mechanisms of dissemination of these two resistance determinants. The aph(3')-Ia gene is located on different conjugative plasmid scaffolds and is associated with two distinct transposable elements (Tn903 and Tn4352) that contributed to its spread. The diffusion of aph(3')-Ib is mediated by a small non-conjugative, mobilizable chimeric plasmid that likely derived from distantly related members of the Pseudomonadota phylum and was not associated with any detectable mobile genetic element. Although the spread of neomycin resistance is largely attributable to horizontal transfer, both resistance determinants have been acquired by a predominant lineage (ST100) associated with enterotoxigenic E. coli, which accounted for approximately one-third of the strains.

Corynebacterium ramonii sp. nov., a novel toxigenic member of the Corynebacterium diphtheriae species complex

The Corynebacterium diphtheriae species complex comprises seven bacterial species, including Corynebacterium ulcerans, a zoonotic pathogen from multiple animal species. In this work, we characterise phenotypically and genotypically isolates belonging to two C. ulcerans lineages. Results from phylogenetic analyses, in silico DNA-DNA hybridization (DDH) and MALDI-TOF spectra differentiate lineage 2 from C. ulcerans lineage 1, which, together with their distinct transmission dynamics (probable human-to-human vs animal-to-human), indicates that lineage 2 is a separate Corynebacterium species, which we propose to name Corynebacterium ramonii. This species is of particular medical interest considering that its human-to-human transmission is likely, and that some C. ramonii isolates carry the diphtheria toxin gene.

Multiplicity of blaKPC Genes and pKpQIL Plasmid Plasticity in the Development of Ceftazidime-Avibactam and Meropenem Coresistance in Klebsiella pneumoniae Sequence Type 307

In 2021, Klebsiella pneumoniae sequence type 307 (ST307) strains causing pulmonary and bloodstream infections identified in a hospital in Rome, Italy, reached high levels of resistance to ceftazidime-avibactam (CZA). One of these strains reached high levels of resistance to both CZA and carbapenems and carried two copies of blaKPC-3 and one copy of blaKPC-31 located on plasmid pKpQIL. The genomes and plasmids of CZA-resistant ST307 strains were analyzed to identify the molecular mechanisms leading to the evolution of resistance and compared with ST307 genomes at local and global levels. A complex pattern of multiple plasmids in rearranged configurations, coresident within the CZA-carbapenem-resistant K. pneumoniae strain, was observed. Characterization of these plasmids revealed recombination and segregation events explaining why K. pneumoniae isolates from the same patient had different antibiotic resistance profiles. This study illustrates the intense genetic plasticity occurring in ST307, one of the most worldwide-diffused K. pneumoniae high-risk clones.

Corynebacteria of the diphtheriae Species Complex in Companion Animals: Clinical and Microbiological Characterization of 64 Cases from France

Corynebacteria of the diphtheriae species complex (CdSC) can cause diphtheria in humans and have been reported from companion animals. We aimed to describe animal infection cases caused by CdSC isolates. A total of 18,308 animals (dogs, cats, horses, and small mammals) with rhinitis, dermatitis, nonhealing wounds, and otitis were sampled in metropolitan France (August 2019 to August 2021). Data on symptoms, age, breed, and the administrative region of origin were collected. Cultured bacteria were analyzed for tox gene presence, production of the diphtheria toxin, and antimicrobial susceptibility and were genotyped by multilocus sequence typing. Corynebacterium ulcerans was identified in 51 cases, 24 of which were toxigenic. Rhinitis was the most frequent presentation (18/51). Eleven cases (6 cats, 4 dogs, and 1 rat) were monoinfections. Large-breed dogs, especially German shepherds (9 of 28 dogs; P < 0.00001), were overrepresented. C. ulcerans isolates were susceptible to all tested antibiotics. tox-positive C. diphtheriae was identified in 2 horses. Last, 11 infections cases (9 dogs and 2 cats; mostly chronic otitis and 2 sores) had tox-negative C. rouxii, a recently defined species. C. rouxii and C. diphtheriae isolates were susceptible to most antibiotics tested, and almost all of these infections were polymicrobial. Monoinfections with C. ulcerans point toward a primary pathogenic potential to animals. C. ulcerans represents an important zoonotic risk, and C. rouxii may represent a novel zoonotic agent. This case series provides novel clinical and microbiological data on CdSC infections and underlines the need for management of animals and their human contacts. IMPORTANCE We report on the occurrence and clinical and microbiological characteristics of infections caused by members of the CdSC in companion animals. This is the first study based on the systematic analysis of a very large animal cohort (18,308 samples), which provides data on the frequency of CdSC isolates in various types of clinical samples from animals. Awareness of this zoonotic bacterial group remains low among veterinarians and veterinary laboratories, among which it is often considered commensal in animals. We suggest that in the case of CdSC detection in animals, the veterinary laboratories should be encouraged to send the samples to a reference laboratory for analysis of the presence of the tox gene. This work is relevant to the development of guidelines in the case of CdSC infections in animals and underlines their public health relevance given the zoonotic transmission risk.

Global spread and evolutionary convergence of multidrug-resistant and hypervirulent Klebsiella pneumoniae high-risk clones

For people living in developed countries life span is growing at a faster pace than ever. One of the main reasons for such success is attributable to the introduction and extensive use in the clinical practice of antibiotics over the course of the last seven decades. In hospital settings, Klebsiella pneumoniae represents a well-known and commonly described opportunistic pathogen, typically characterized by resistance to several antibiotic classes. On the other hand, the broad wedge of population living in Low and/or Middle Income Countries is increasing rapidly, allowing the spread of several commensal bacteria which are transmitted via human contact. Community transmission has been the original milieu of K. pneumoniae isolates characterized by an outstanding virulence (hypervirulent). These two characteristics, also defined as "pathotypes", originally emerged as different pathways in the evolutionary history of K. pneumoniae. For a long time, the Sequence Type (ST), which is defined by the combination of alleles of the 7 housekeeping genes of the Multi-Locus Sequence Typing, has been a reliable marker of the pathotype: multidrug-resistant clones (e.g. ST258, ST147, ST101) in the Western world and hypervirulent clones (e.g. ST23, ST65, ST86) in the Eastern. Currently, the boundaries separating the two pathotypes are fading away due to several factors, and we are witnessing a worrisome convergence in certain high-risk clones. Here we review the evidence available on confluence of multidrug-resistance and hypervirulence in specific K. pneumoniae clones.

Genome-Based Retrospective Analysis of a Providencia stuartii Outbreak in Rome, Italy: Broad Spectrum IncC Plasmids Spread the NDM Carbapenemase within the Hospital

Providencia stuartii is a member of the Morganellaceae family, notorious for its intrinsic resistance to several antibiotics, including last-resort drugs such as colistin and tigecycline. Between February and March 2022, a four-patient outbreak sustained by P. stuartii occurred in a hospital in Rome. Phenotypic analyses defined these strains as eXtensively Drug-Resistant (XDR). Whole-genome sequencing was performed on the representative P. stuartii strains and resulted in fully closed genomes and plasmids. The genomes were highly related phylogenetically and encoded various virulence factors, including fimbrial clusters. The XDR phenotype was primarily driven by the presence of the bla_NDM-1 metallo-β-lactamase alongside the rmtC 16S rRNA methyltransferase, conferring resistance to most β-lactams and every aminoglycoside, respectively. These genes were found on an IncC plasmid that was highly related to an NDM-IncC plasmid retrieved from a ST15 Klebsiella pneumoniae strain circulating in the same hospital two years earlier. Given its ability to acquire resistance plasmids and its intrinsic resistance mechanisms, P. stuartii is a formidable pathogen. The emergence of XDR P. stuartii strains poses a significant public health threat. It is essential to monitor the spread of these strains and develop new strategies for their control and treatment.

Ceftazidime/avibactam-resistant meropenem-susceptible KPC-producing Klebsiella pneumoniae: analysis of cases and evaluation of in-vitro activity of fosfomycin-containing combinations

BACKGROUND

Little is known regarding outcomes and optimal therapeutic regimens of infections caused by KPC-producing Klebsiella pneumoniae (KPC-Kp) resistant to ceftazidime/avibactam (CZA) and susceptible to meropenem (MEM). Although in-vitro susceptible to MEM, the possibility of developing MEM resistance overtime is a concern. We described the clinical characteristics of patients with colonization/infection due to KPC-variant with a focus on the in-vitro activity of fosfomycin (FOS)-containing combinations.

MATERIALS/METHODS

Patients with colonization/infection due to KPC-variant were included. FOS susceptibility was performed by agar dilution method. Synergistic activity of FOS-based combinations was evaluated by gradient strip-agar diffusion method. The emergence of in-vitro MEM resistance was also tested.

RESULTS

Eleven patients were included, 8 with infection [4 ventilator-associated pneumonia, 4 bloodstream infections], 3 with colonization. A previous therapy with CZA was administered to all the patients (mean cumulative duration 23 days). All subjects with infection received meropenem, in monotherapy (n=4) or with amikacin (n=2) or fosfomycin (n=2) and achieved clinical cure. A new CZA-susceptible and MEM-resistant KPC-Kp strain was subsequently isolated in 3 patients (27.3%). Meropenem/vaborbactam (MVB) showed high in-vitro activity, while FOS+MEM combination was synergistic in 40% of cases. In-vitro resistance to MEM was observed, with maintenance of CZA resistance.

DISCUSSION

Detection of KPC-variant may occur within the same patient, especially if CZA has been previously administered. Although clinical success has been obtained with carbapenems, the emergence of MEM resistance is a concern. Fosfomycin plus meropenem is synergistic and may represent a valuable combination option for KPC-variant, while MVB may be considered in monotherapy.

IMPORTANCE

The detection of KPC-variants in an endemic setting for KPC-Kp represents a worryingly emerging condition. The optimal therapeutic approach is still unknown and the development of meropenem resistance is a concern, which may finally lead to a therapeutic failure in the clinical practice. In these cases, the addition of fosfomycin to meropenem or a more potent antibiotic such as meropenem/vaborbactam may represent valuable therapeutic options.

Ceftazidime-avibactam resistance in Klebsiella pneumoniae sequence type 37: a decade of persistence and concealed evolution

The first reports of carbapenem-resistant Enterobacterales in our hospital date back to 2006. In that period, few ertapenem-resistant but meropenem-susceptible Klebsiella pneumoniae isolates belonging to sequence type (ST) 37 were retrieved from clinical samples. These strains produced the CTX-M-15 extended spectrum β-lactamase, OmpK35 was depleted due to a nonsense mutation, and a novel OmpK36 variant was identified. Yet, starting from 2010, Klebsiella pneumoniae carbapenemase (KPC)-producing ST512 isolates started prevailing and ST37 vanished from sight. Since 2018 the clinical use of the combination of ceftazidime-avibactam (CZA) has been introduced in clinical practice for the treatment of bacteria producing serine-β-lactamases, but KPC-producing, CZA-resistant K. pneumoniae are emerging. In 2021, four CZA-resistant ST37 isolates producing KPC variants were isolated from the same number of patients. blaKPC gene cloning in Escherichia coli was used to define the role of those KPC variants on CZA resistance, and whole genome sequencing was performed on these isolates and on three ST37 historical isolates from 2011. CZA resistance was due to mutations in the blaKPC genes carried on related pKpQIL-type plasmids, and three variants of the KPC enzyme have been identified in the four ST37 strains. The four ST37 isolates were closely related to each other and to the historical isolates, suggesting that ST37 survived without notice in our hospital for 10 years, waiting to re-emerge as a CZA-resistant K. pneumoniae clone. The ancestor of these contemporary isolates derives from ST37 wild-type porin strains, with no other mutations in chromosomal genes involved in conferring antibiotic resistance (parC, gyrA, ramR, mgrB, pmrB).

Multidrug-resistant toxigenic Corynebacterium diphtheriae sublineage 453 with two novel resistance genomic islands

Antimicrobial therapy is important for case management of diphtheria, but knowledge on the emergence of multidrug-resistance in Corynebacterium diphtheriae is scarce. We report on the genomic features of two multidrug-resistant toxigenic isolates sampled from wounds in France 3 years apart. Both isolates were resistant to spiramycin, clindamycin, tetracycline, kanamycin and trimethoprim-sulfamethoxazole. Genes ermX, cmx, aph(3')-Ib, aph(6)-Id, aph(3')-Ic, aadA1, dfrA15, sul1, cmlA, cmlR and tet(33) were clustered in two genomic islands, one consisting of two transposons and one integron, the other being flanked by two IS6100 insertion sequences. One isolate additionally presented mutations in gyrA and rpoB and was resistant to ciprofloxacin and rifampicin. Both isolates belonged to sublineage 453 (SL453), together with 25 isolates from 11 other countries (https://bigsdb.pasteur.fr/diphtheria/). SL453 is a cosmopolitan toxigenic sublineage of C. diphtheriae, a subset of which acquired multidrug resistance. Even though penicillin, amoxicillin and erythromycin, recommended as the first line in the treatment of diphtheria, remain active, surveillance of diphtheria should consider the risk of dissemination of multidrug-resistant strains and their genetic elements.

An outbreak sustained by ST15 Klebsiella pneumoniae carrying 16S rRNA methyltransferases and blaNDM: evaluation of the global dissemination of these resistance determinants

The spread of extremely-drug resistant Klebsiella pneumoniae has become a major health threat worldwide. This is largely mediated by certain lineages, recognized as high-risk clones dispersed in all the world. The analysis of an outbreak of nine ST15, NDM-1 metallo-β-lactamase producing K. pneumoniae was performed. An IncC plasmid carrying the bla_NDM-1 gene also carried the rare rmtC gene, encoding for a 16S rRNA methyltransferases (16RMTases), conferring resistance to all aminoglycosides. We studied the global spread of NDM variants and their association with the 16RMTases among K. pneumoniae complete genomes available in GenBank, producing a complete overview of the association of 16RMTases and NDM in K. pneumoniae genomics. NDM is more and more often associated with16RMTases and both are spreading in K. pneumoniae, conferring resistance to every beta-lactam and aminoglycoside. Our analysis suggest that aminoglycosides have limited future as second line treatment against NDM-producing K. pneumoniae.

Virulence plasmid pINV as a genetic signature for Shigella flexneri phylogeny

Shigella flexneri is a major health burden in low- and middle-income countries, where it is a leading cause of mortality associated with diarrhoea in children, and shows an increasing incidence among travellers and men having sex with men. Like all Shigella spp., S. flexneri has evolved from commensal Escherichia coli following the acquisition of a large plasmid pINV, which contains genes essential for virulence. Current sequence typing schemes of Shigella are based on combinations of chromosomal genetic loci, since pINV-encoded virulence genes are often lost during growth in the laboratory, making these elements inappropriate for sequence typing. By performing comparative analysis of pINVs from S. flexneri strains isolated from different geographical regions and belonging to different serotypes, we found that in contrast to plasmid-encoded virulence genes, plasmid maintenance genes are highly stable pINV-encoded elements. For the first time, to our knowledge, we have developed a S. flexneri plasmid multilocus sequence typing (pMLST) method based on different combinations of alleles of the vapBC and yacAB toxin–antitoxin (TA) systems, and the parAB partitioning system. This enables typing of S. flexneri pINV plasmids into distinct ‘virulence sequence types’ (vSTs). Furthermore, the phylogenies of vST alleles and bacterial host core genomes suggests an intimate co-evolution of pINV with the chromosome of its bacterial host, consistent with previous findings. This work demonstrates the potential of plasmid maintenance loci as genetic characteristics to study as well as to trace the molecular phylogenesis of S. flexneri pINV and the phylogenetic relationship of this plasmid with its bacterial host.

Spread of hypervirulent multidrug-resistant ST147 Klebsiella pneumoniae in patients with severe COVID-19: an observational study from Italy, 2020-21

Objectives

To report an outbreak of hypervirulent Klebsiella pneumoniae (hvKp) in COVID-19 patients.

Methods

Prospective, observational study including consecutive COVID-19 patients with hvKp infections admitted to the University Hospital of Pisa (Italy). Clinical data and outcome of patients were collected. All patients were followed-up to 30 days from the diagnosis of infection. Mortality within 30 days of the diagnosis of hvKp infection was reported. The hypermucoviscous phenotype was determined by the ‘string test’. Molecular typing was performed on three strains collected during different periods of the outbreak. The strains underwent whole genome sequencing using the Illumina MiSeq instrument. The complete circular assemblies were also obtained for the chromosome and a large plasmid using the Unicycler tool.

Results

From November 2020 to March 2021, hvKp has been isolated from 36 COVID-19 patients: 29/36 (80.6%) had infections (15 bloodstream infections, 8 ventilator-associated pneumonias and 6 complicated urinary tract infections), while 7/36 (19.4%) had colonization (3 urine, 2 rectal and 2 skin). The isolates belonged to ST147 and their plasmid carried three replicons of the IncFIB (Mar), IncR and IncHI1B types and several resistance genes, including the rmpADC genes encoding enhancers of capsular synthesis. The hvKp isolates displayed an ESBL phenotype, with resistance to piperacillin/tazobactam and ceftolozane/tazobactam and susceptibility only to meropenem and ceftazidime/avibactam. The majority of patients were treated with meropenem alone or in combination with fosfomycin. Thirty-day mortality was 48.3% (14/29).

Conclusions

ST147 ESBL-producing hvKp is associated with high mortality in COVID-19 patients. Strict microbiological surveillance and infection control measures are needed in this population.

Interplay between Klebsiella pneumoniae producing KPC-31 and KPC-3 under treatment with high dosage meropenem: a case report

The objective was to study ceftazidime-avibactam resistant and susceptible Klebsiella pneumoniae isolated from a patient admitted to the Policlinico Umberto I of Rome for SARS-CoV2. Data on the evolution of patient's conditions, antimicrobial therapies, and microbiological data were collected. Whole-genome sequencing performed by Illumina and Nanopore sequencing methods were used to type the strains. During the hospitalization, a SARS-CoV2-infected patient was colonized by a KPC-producing K. pneumoniae strain and empirically treated with ceftazidime-avibactam (CZA) when presenting spiking fever symptoms. Successively, ST2502 CZA-resistant strain producing the KPC-31 variant gave a pulmonary infection to the patient. The infection was treated with high doses of meropenem. The KPC-31-producing strain disappeared but the patient remained colonized by a KPC-3-producing K. pneumoniae strain. An interplay between highly conserved KPC-31- and KPC-3-producing ST2502 strains occurred in the SARS-CoV2 patient during the hospitalization, selected by CZA and carbapenem treatments, respectively.

Chest computed tomography score, cycle threshold values and secondary infection in predicting COVID-19 mortality

This retrospective and observational cohort study investigated chest computed tomography (CT) findings, cycle threshold (Ct) values in RT-PCR of SARS-CoV-2 and secondary infection occurrence to predict prognosis in COVID-19 patients. At hospital admission, CT findings and Ct values were collected. Microbiology tests performed after 48 hours from hospitalization were reviewed. According to in-hospital mortality, patients were grouped into non-survivors and survivors. Among 283 patients evaluated, in-hospital mortality rate was 13.8% (39/283). Secondary infection occurrence was 15.2% (43/283). Cut-off values for CT score >13.5 (AUC=0.682 p=0.0009) and for Ct <23.4 (AUC=0.749, p<0.0001) were predictive of death. Super-additive and synergic effects between high CT score plus secondary infection occurrence as well as between high CT score plus low Ct values affecting patient's outcome were observed. Chest CT score and Ct values in RT-PCR of SARS-CoV-2 could have a combination role for severity stratification of COVID-19 patients.

Meropenem-Vaborbactam as Salvage Therapy for Ceftazidime-Avibactam-, Cefiderocol-Resistant ST-512 Klebsiella pneumoniae-Producing KPC-31, a D179Y Variant of KPC-3

A 68-year-old man had recurrent bacteremia by Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae resistant to ceftazidime-avibactam and cefiderocol. The sequencing of a target region showed that it harbored a KPC-3 variant enzyme (D179Y; KPC-31), which confers resistance to ceftazidime-avibactam and restores meropenem susceptibility. The patient was successfully treated with meropenem-vaborbactam.

Molecular epidemiology of NDM-5-producing Escherichia coli high-risk clones identified in two Italian hospitals in 2017-2019

Between November 2018 and October 2019, carbapenem-resistant Enterobacterales carrying New Delhi Metallo-β-lactamase (NDM) caused one of the largest and persistent outbreaks occurred in Italy and intensified surveillance measures have been taken in all Italian hospitals. In this study we analyzed NDM-5- producing Escherichia coli identified in 2 hospitals of the Lazio region in Italy. Epidemiological and microbiological data demonstrated that in 2018-2019 the NDM-5-producing high-risk E. coli ST167 clone circulated in patients from both hospitals. In 2019, another NDM-5-producing E. coli clone, identified by MLST as ST617 was introduced in one of the 2 hospitals and caused an outbreak. This study describes an application of genomics as a useful method to discern endemic and outbreak clones when applied to strains of the same species (E. coli) with the same resistance determinant (NDM-5) and the relevance of screening patients admitted in critical units for carbapenemase producers to prevent outbreaks.

In vitro activity of fosfomycin against mucoid and non-mucoid Pseudomonas aeruginosa strains

OBJECTIVES

Pseudomonas aeruginosa is the most frequent infectious agent in cystic fibrosis patients. P. aeruginosa resistance to first line antibiotics limits therapeutic options, but the therapeutic potential of older generation antibiotics, such as fosfomycin is under investigation. Fosfomycin does not belong to any other antibiotic class and acts by inhibiting the biosynthesis of the bacterial cell wall during the initial phases. A major problem for the use of fosfomycin against P. aeruginosa is the absence of a clinical breakpoint, the last one of 32 μg/mL was proposed in 2013 by the CA-SFM (Comité de l'Antibiogramme de la Société Française de Microbiologie).

METHODS

Sixty-one strains of P. aeruginosa (thirty mucoid and thirty-one non mucoid) were collected from respiratory samples of cystic fibrosis patients. All isolates were identified by MALDI-TOF (Bruker, Bremen, Germany). Fosfomycin MICs against P. aeruginosa were measured using an automated system and confirmed by the gold standard method.

RESULTS

There was no significant difference between mucoid and non-mucoid strains. MIC distribution and susceptibility rates were obtained by agar dilution method and from this data we measured MIC50 and MIC90 which were equal to 32 μg/mL and 64 μg/mL, respectively. From automated method results we measured a very major error (VME), major error (ME) and categorical agreement (CA) which were equal to 0%, 11% and 89%, respectively. Comparing automated and agar dilution methods, a Cohen's kappa equal to 73% (0.726) was measured.

CONCLUSIONS

Our data suggest that fosfomycin has good effect against mucoid and non-mucoid strains of P. aeruginosa and automated systems can be implemented in clinical microbiology laboratories to assess fosfomycin with rapid and reproducible results.

Beyond appearance: An unusual manifestation of isolated oral secondary syphilis

Syphilis is a sexually acquired chronic infection caused by Treponema pallidum and is characterized by a variety of clinical manifestations. The secondary stage of the disease results from the hematogenous and lymphatic dissemination of treponemes after a few weeks or months, and it is characterized by recurrent activity of the disease, with muco-cutaneous as well as systemic manifestations. Mucosal lesions range from small, superficial ulcers that resemble painless aphthae to large gray plaques, and they are generally associated with systemic manifestations of the disease. The exclusive asymptomatic oral localization not associated with general manifestations is uncommon but may actually be unrecognized and under-reported. We report a case of isolated oral manifestation as the unique presentation of secondary syphilis.

How appropriate is the use of rehabilitation facilities? Assessment by an evaluation tool based on the AEP protocol

BACKGROUND

During the last few decades, an increasing attention has been drawn to public health expenditure and resource use. The increasing aging population has highlighted the need to deliver post-acute care and to assess its appropriateness. The "PRUO rehab" (Protocollo di Revisione dell'Utilizzo dell'Ospedale riabilitativo) protocol was realized and validated to assess the appropriateness of use of rehabilitation units. The aims of this study were to test the validity of the PRUO-rehab tool and to analyse the causes for Inappropriate Hospital Stay (IPS) in rehabilitation units.

METHODS

The PRUO rehab tool was retrospectively applied to the medical records of 502 patients who stayed at least overnight in one of ten different rehabilitation units set in Northern Italy, during 2007.

RESULTS

The tool was valid and the inappropriate patient stay (IPS) score was 25.0%.

CONCLUSION

Although reasonably low, the IPS indicates that the rehabilitation structures analysed could be used more efficiently.

Bicyclic compounds with potential antiulcer and/or antisecretory activity. II. 1(or 3),4,6,7-Tetrahydro-1(3)H-pyrano[3,4-d]imidazoles and 1(or 3),4,6,7-tetrahydro-1(3)H-thiopyrano[3,4-d]imidazoles

Owing to our current interest in synthesizing and evaluating the antiulcer and antisecretory activity of bicyclic compounds, a series of 1(or 3),4,6,7-tetrahydropyrano- and 1(or 3),4,6,7-tetrahydrothiopyrano-[3,4-d]imidazoles was synthesized and tested. The biological results were compared with those of some previously described 4,5,6,7-tetrahydroimidazo-[4,5-c]pyridine and 4,5,6,7-tetrahydrobenzimidazole derivatives.

7-trans-(2-Pyridylethenyl)-5H-thiazolo[3,2-a]pyrimidine-5-ones: synthesis and pharmacological activity

A series of 7-trans-(2-pyridylethenyl)-5H-thiazolo[3,2-a]pyrimidine-5-ones was synthesized and evaluated for their pharmacological activity. Some compounds were found to be effective in inhibiting restraint ulcers in the rat. Two of them also showed interesting antiinflammatory activity.

Bicyclic compounds with potential antiulcer and/or antisecretory activity. I. 4,5,6,7-Tetrahydrobenzimidazoles

The remarkable antiulcer and antisecretory activity of some previously described 4,5,6,7-tetrahydroimidazo[4,5-c]pyridine derivatives prompted us to further investigate related bicyclic systems. Accordingly, a series of 5-amino- and 5-aminomethyl-4,5,6,7-tetrahydrobenzimidazoles, regiospecifically alkylated in position 1, were synthesized and tested. Only a few 1-ethyl-5-amino derivatives displayed a reasonable antiulcer activity in comparison with our former class of compounds.

New derivatives of pyrrolo and pyrido[2,1-b] quinazoline as antiulcer agents

A series of 3-benzylidene-1,2,3,9-tetrahydro-9-oxopyrrolo-[2,1-b] quinazolinecarboxylic acids and 6-benzylidene-6,7,8,9-tetrahydro-11-oxo-11H-pyrido[2,1-b] quinazolinecarboxylic acid was synthesized and evaluated for their antiulcer activity by the test of inhibition of restraint ulcers in the rat, and for gastric antisecretory activity using the technique of Shay. Some compounds appear potentially useful for therapeutic application.

Anti-ulcer and antisecretory activity of selected imidazopiperidines

New thioureas and ureas with an interesting anti-ulcer and antisecretory activity are disclosed. The chemical synthesis, determination of the structure, and structure-activity relationships of the compounds are discussed.

Antinociceptive, prolactin releasing and intestinal motility inhibiting activities of dermorphin and analogues after subcutaneous administration in the rat

A series of analogues and shorter homologues of dermorphin (DM), a frog skin heptapeptide with potent morphine-like activity, have been assayed in the rat after subcutaneous (SC) administration at the screening dose of 4 mg/kg. The effects taken into account are: analgesia (tail-pinch test), stimulation of prolactin (PRL) secretion, and inhibition of gastro-intestinal (GI) motility (charcoal meal transit). Effective doses were calculated for the most active compounds. The potency of DM (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) in the different tests was: tail-pinch: ED50 = 0.83 mg/kg; PRL release: ED100 = 0.3 mg/kg; inhibition of GI motility: ED30 = 1.8 mg/kg.

Ergoline derivatives. Note XIII (1) alpha-adrenergic blocking drugs

The synthesis and the pharmacological activities of 24 analogues of the alpha-adrenergic blocking drug, nicergoline (I b), are reported. The majority of the new compounds were found to be less active than (I b): the structure-activity relationships are presented and discussed.

Biological activities of a combination of medroxyprogesterone acetate and ethinyloestradiol

Combinations of medroxyprogesterone acetate (mg): ethinyloestradiol (μg) were studied in four different ratios, i. e. 2 : 75, 2.5 : 75, 5 : 75, 5 : 50. The ratios were administered up to the 200-fold dose per kg body weight and well tolerated.

The combination of the two steroids led to a potentation of the antiovulatory and gonadotrophin inhibiting activity. No side-effects were detected. The data allow of the conclusion that the ratio 2 : 75 is sufficient to inhibit the central control mechanism and thus ovulation.