Dissemination of Klebsiella pneumoniae ST147 NDM-1 in Poland, 2015-19.

OBJECTIVES: To assess the spread of New Delhi metallo-ß-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae ST147 organisms in Poland since an introduction from Tunisia in March 2015, including their phylogenetic position in the global population of the high-risk clone. METHODS: Out of 8925 unique NDM-positive K. pneumoniae isolates identified in Poland from April 2015 till December 2019, 126 isolates, including the Tunisian imports, were related by PFGE and blaNDM gene-carrying Tn125 transposon derivatives. Forty-seven representative isolates were sequenced by Illumina MiSeq. The phylogeny, resistome, virulome and plasmid replicons were analysed and compared with the international ST147 strains. Plasmids of six isolates were studied by the MinION sequencing. RESULTS: A high homogeneity of the 47 isolates was observed, with minor variations in their resistomes and plasmid replicon profiles. However, the detailed SNP comparison discerned a strict outbreak cluster of 40 isolates. All of the organisms were grouped within the ST147 phylogenetic international lineage, and four NDM-1 producers from Tunisia, Egypt and France were the closest relatives of the Polish isolates. Yersiniabactin genes (YbST280 type) were located within the ICEKpn12-like element in most of the outbreak isolates, characterized by O2v1 and KL64 antigen loci. The blaNDM-1 genes were located in double-replicon IncFIIK2+IncFIBK plasmids. CONCLUSIONS: The continuous spread of K. pneumoniae ST147 NDM-1 in Poland since 2015, largely in the Warsaw area, is demonstrated by this genomic analysis. The isolates showed a high degree of homogeneity, and close relatedness to organisms spreading in the Mediterranean region.

Bacteriological Assessment of Pneumonia Caused by Gram-Negative Bacteria in Patients Hospitalized in Intensive Care Unit.

The article presents the results of 11-year study (2005-2015) of Gram-negative bacteria responsible for pneumonia in 2033 mechanically ventilated patients hospitalized in Intensive Care Unit. Of 8796 biological samples, consisting mainly of bronchial aspirate (97.9 %), 2056 bacterial strains were isolated and subjected to identification. VITEK 2 was used to determine drug susceptibility (classified according to the EUCAST criteria). ESBL, MBL and KPC-producing strains were identified by means of phenotypic methods using appropriate discs. The findings were that the predominant bacteria responsible for infections consisted of Enterobacteriaceae (42.0 %), Acinetobacter baumannii (37.2 %), Pseudomonas aeruginosa (16.1 %), and Stenotrophomonas maltophila (4.7 %). We observed a rise in the number of bacteria causing pneumonia throughout the study period, especially in S. maltophila and Enterobacteriaceae ESBL (+). Gram-negative bacilli were 100 % susceptible to colistin, apart from naturally resistant strains such as Proteus mirabilis, Serratia marcescens, whereas Enterobacteriaceae ESBL (+) were susceptible to imipenem and meropenem. Acinetobacter baumannii strains exhibited the lowest drug susceptibility. In conclusion, we report an increase in the prevalence of pneumonia associated with Gram-negative bacteria in mechanically ventilated intensive care patients. Colistin remains the most effective drug against the majority of Gram-negative bacteria. Therapeutic problems are common in the course of treatment of Acinetobacter baumannii infections.

Effectiveness of immunoprophylaxis in suppressing carriage of Neisseria meningitidis in the military environment.

Neisseria meningitidis, etiological factor of invasive meningococcal disease, is a human commensal that colonizes the nasopharynx. Colonization is usually asymptomatic, but it is a prerequisite for disease. Asymptomatic carriers are the major source of infection. In the present study, a survey of N. meningitidis carriage was conducted between January and March 2013 in a military unit in Poland. Single-time throat culture samples were collected from professional 559 soldiers (302 unvaccinated vs. 257 vaccinated individuals with the quadrivalent conjugate vaccine ACYW-135). Bacterial identification was performed with classic microbiological methods (culture, incubation, identification). Non-culture method (PCR) was used for confirmation of detected strains of N. meningitidis and determination of serogroups. We found 29 carriers in the group of unvaccinated soldiers (9.6 % of examined individuals) whereas among vaccinated soldiers only 3 persons were carriers of N. meningitidis (1.2 %). The most frequently identified serogroups among the carriers serving in the same military facility were serogroup B (28 %), followed by Y (25 %), and C (22 %). In conclusion, the initiation of mass vaccination with the quadrivalent conjugate vaccine ACYW-135 in the military environment seems an effective method of suppressing N. meningitidis carriage.

Etiological factors causing lower respiratory tract infections isolated from hospitalized patients.

Lower respiratory tract infections (LRTI) account for 20-30 % of all hospital-acquired contagions. They are characterized by high mortality of hospitalized patients. The most serious form of LRTI is pneumonia, and the most common etiological factors in such cases are bacteria. The article gives the analysis of bacterial flora samples obtained from lower respiratory tract of hospitalized patients. In vitro susceptibility of pathogens to selected antibiotics has also been assessed. We carried out a retrospective analysis of 1,171 bacterial strains isolated from 1,171 patients treated in clinics of the Military Institute of Medicine in Warsaw, Poland. In most cases the samples were collected from an endotracheal or tracheostomic tube (71.5 %) and from bronchoalveolar lavage (21.7 %). The most commonly isolated pathogens included Acinetobacter baumannii (35.8 %), Staphylococcus aureus (27.6 %), Klebsiella pneumoniae (19.4 %), and Pseudomonas aeruginosa (16.2 %). Multidrug-resistant gram-negative bacteria exhibited 100 % susceptibility to colistin only. Klebsiella pneumoniae ESBL+ and Acinetobacter baumannii were most susceptible to carbapenems, while Pseudomonas aeruginosa strains to ceftazidime. Methicillin-resistant Staphylococcus aureus were 100 % susceptible to vancomycin, linezolid, and tigecycline. In conclusion, identifying the etiological factors causing infections of the lower respiratory tract and determining their drug-susceptibility is of key importance in empirical treatment.

NDM-1- or OXA-48-producing Enterobacteriaceae colonising Polish tourists following a terrorist attack in Tunis, March 2015.

We describe the introduction of NDM-1-producing Klebsiella pneumoniae ST147 and Escherichia coli ST410, and OXA-48-producing K. pneumoniae ST101 strains to Poland by two patients transported to the country after hospitalisation in Tunisia. The patients had gunshot wounds following the terrorist attack in the Bardo National Museum in Tunis in March 2015. Our report reinforces the need for microbiological screening of patients returning from travel on admission to healthcare institutions, especially following hospitalisation in countries where carbapenemase-producing Enterobacteriaceae are endemic.

In vitro sensitivity of Acinetobacter baumannii and Pseudomonas aeruginosa to carbapenems among intensive care unit patients.

Acinetobacter baumannii and Pseudomonas aeruginosa pathogens are the most common causes of fatal pneumonia among patients treated in Intensive Care Units (ICU). Carbapenems remain a group of antibiotics characterized by the highest effectiveness in treatment of heavy infections of the lower respiratory tract. This study compared in vitro sensitivity of A. baumannii and P. aeruginosa to three carbapenems: imipenem, meropenem and doripenem. The material was collected from 71 patients treated in the ICU from April 2009 to January 2010. Bronchial tree was the predominant source of samples. Fifty-four strains of A. baumannii and 17 strains of P. aeruginosa were analyzed. Sensitivity to carbapenems was interpreted in line with Clinical and Laboratory Standard Institute (CLSI) and European Committee for Antimicrobial Susceptibility Testing (EUCAST) criteria (imipenem and meropenem) or in compliance with the Food and Drug Administration (FDA) and CLSI guidelines (doripenem). We found that A. baumannii was significantly more often sensitive to imipenem than to doripenem and meropenem, but only according to the CLSI and FDA and not EUCAST criteria. The sensitivity of P. aeruginosa was higher to imipenem than to doripenem and meropenem, according to both CLSI and EUCAST criteria (64.7 %). We conclude that the EUCAST criteria demonstrate a higher rigor than those of CLSI and FDA in the determination of carbapenems sensitivity. Imipenem appears more effective than doripenem and meropenem in treatment of A. baumannii and P. aeruginosa infections.

In vitro susceptibility of Staphylococci and Enterococci to vancomycin and teicoplanin.

Hospital-acquired infections (HAIs) pose a worldwide problem. They primarily concern intensive care, hematology-oncology, and surgical units. Coagulase-positive and coagulase-negative Staphylococci, especially their subgroups possessing the ability to develop resistance to methicillin, and Enterococci have a particular role in the etiology of HAIs. The aim of this study was to determine the therapeutic minimal inhibitory concentration (MIC) values for vancomycin and teicoplanin, two of the most commonly administered antibiotics in the treatment of infections caused by Staphylococci resistant to methicillin, and infections caused by Enterococci. The material analyzed included 200 bacterial strains collected from patients treated in the Intensive Care Unit, the Musculoskeletal Infections Unit, and Surgical Clinics of the Military Institute of Medicine in Warsaw, Poland. The study was conducted in accord with the European Committee for Antimicrobial Susceptibility Testing (EUCAST) criteria by means of the Etest® gradient strips. We demonstrate a full susceptibility of Staphylococci MSSA (methicillin susceptible Staphylococcus aureus), Staphylococci MRSA (methicillin resistant Staphylococcus aureus), and Enterococci to both antibiotics. Coagulase-negative Staphylococci had a higher sensitivity to vancomycin. Teicoplanin had a lower MIC than vancomycin against the analyzed strains of Enterococci. As regards the coagulase-negative Staphylococci, vancomycin had a lower MIC than teicoplanin. In conclusion, the study confirmed current recommendations on the use of vancomycin and teicoplanin in the treatment of infections caused by gram-positive bacteria, emphasizing the need for the determination of MIC values.

Prevalence of acute respiratory tract diseases among soldiers deployed for military operations in Iraq and Afghanistan.

Respiratory diseases are one of the most common health problems among service personnel assigned to contemporary military operations which are conducted in areas characterized by adverse environmental conditions. This article reviews the results of the studies into the prevalence of acute respiratory tract diseases among soldiers of the Polish Military Contingent deployed to Iraq and Afghanistan. The article also discusses a number of factors which increase the prevalence of diseases diagnosed in the population of soldiers on a military mission in different climatic and sanitary conditions. Retrospective analysis was based on medical records of Polish troops treated on an outpatient basis in Iraq in 2003-2004 (n = 871) and in Afghanistan in 2003-2005 (n = 400), 2009 (n = 2,300), and 2010 (n = 2,500). The intensity rates were calculated and were then used to calculate the prevalence of diseases per 100 persons in a given population of the military personnel. We found that acute respiratory tract diseases were one of the most common health problems treated in outpatient medical facilities in all four study populations. The incidence rate was 45.6 cases in Iraq in 2003-2004, and in Afghanistan it amounted to 61.8 in 2003-2005, 45.3 in 2009, and 54.8-100 persons in 2010. In conclusion, the prevalence of respiratory diseases was closely related to the environmental factors, such as sand and dust storms, extreme temperature changes, unsatisfactory sanitary conditions, and common disregard of basic principles concerning disease prevention.

Audiological and radiological study of eight polish patients with alpha-mannosidosis.

Alpha-mannosidase catalyze lysosomal cleaving of mannose residues from glycoproteins. The enzyme is encoded by the MAN2B1 gene. Biallelic pathogenic variants cause enzymatic deficiency, which clinically results in alpha-mannosidosis (AM), an autosomal recessively inherited condition. Typical features observed in AM patients include intellectual disability, loss of speech, dysmorphic features, progressive motor problems, ataxia, hearing impairment and recurrent otitis. The cause of the latter is mainly attributed to immunodeficiency. The aim of our study was to demonstrate the otolaryngologic and hearing outcomes in patients with AM. The study group consisted of 8 AM patients: 6 males and 2 females, aged 2.5-37 yrs. The clinical course, dysmorphic ENT features, hearing status and the HRCT scans of the temporal bones were analyzed. MS Excel for Windows and Statistica software package were used for the comparison of interaural audiometric loss, mean hearing loss and mean hearing threshold for each patient's audiometric frequency tested. We identified ENT dysmorphic features in all of our AM patients, while the hearing loss was detected in 6 out of our 8 patients. For those cases, the onset of deafness was noted in the first decade of life, this impairment was sensorineural, of cochlear origin, bilateral, of a moderate degree (mean loss 62.76 dB; median 60 dB, standard deviation 12.5 dB), symmetrical and stable. The shape of the audiometric curves of our patients can be described as slightly sloping towards the higher tested frequencies, with a marked improvement at 4 kHz. The radiological examination revealed normal structures of the ears, with the exception of one case where a persistent otitis generated a cochlear gap. We therefore concluded that the hearing loss in our AM patients derived from cochlear impairment unrelated with recurrent otitis.