BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are a major public health problem, necessitating the administration of polymyxin E (colistin) as a last-line antibiotic. Meanwhile, the mortality rate associated with colistin-resistant K. pneumoniae infections is seriously increasing. On the other hand, importance of administration of carbapenems in promoting colistin resistance in K. pneumoniae is unknown.
METHODS: We report a case of K. pneumoniae-related pyogenic liver abscess in which susceptible K. pneumoniae transformed into carbapenem- and colistin-resistant K. pneumoniae during treatment with imipenem. The case of pyogenic liver abscess was a 50-year-old man with diabetes and liver transplant who was admitted to Abu Ali Sina Hospital in Shiraz. The K. pneumoniae isolate responsible for community-acquired pyogenic liver abscess was isolated and identified. The K. pneumoniae isolate was sensitive to all tested antibiotics except ampicillin in the antimicrobial susceptibility test and was identified as a non-K1/K2 classical K. pneumoniae (cKp) strain. Multilocus sequence typing (MLST) identified the isolate as sequence type 54 (ST54). Based on the patient\'s request, he was discharged to continue treatment at another center. After two months, he was readmitted due to fever and progressive constitutional symptoms. During treatment with imipenem, the strain acquired blaOXA-48 and showed resistance to carbapenems and was identified as a multidrug resistant (MDR) strain. The minimum inhibitory concentration (MIC) test for colistin was performed by broth microdilution method and the strain was sensitive to colistin (MIC < 2 µg/mL). Meanwhile, on blood agar, the colonies had a sticky consistency and adhered to the culture medium (sticky mucoviscous colonies). Quantitative real-time PCR and biofilm formation assay revealed that the CRKP strain increased capsule wzi gene expression and produced slime in response to imipenem. Finally, K. pneumoniae-related pyogenic liver abscess with resistance to a wide range of antibiotics, including the last-line antibiotics colistin and tigecycline, led to sepsis and death.
CONCLUSIONS: Based on this information, can we have a theoretical hypothesis that imipenem is a promoter of resistance to carbapenems and colistin in K. pneumoniae? This needs more attention.

We report for the first time in Portugal a serotype c Haemophilus influenzae isolated from an adult, with HIV-1 infection. Whole-genome sequencing characterized the isolate as clonal complex ST-7, albeit with a novel MLST (ST2754) due to a unique atpG profile. Integration of this genome with other available H. influenzae serotype c genomes from PubMLST revealed its overall genetic distinctiveness, with the closest related isolate being identified in France in 2020. This surveillance study, involving collaboration among hospitals and reference laboratory, successfully contributed to the identification and characterization of this rare serotype.

Dogs often carry methicillin-resistant Staphylococci asymptomatically. These bacteria are frequently linked to conditions such as canine pyoderma and otitis. Close interaction between dogs and humans can facilitate the exchange of resistant strains, particularly Methicillin-resistant Staphylococcus pseudintermedius (MRSP). This represents a public health issue, since these strains, in addition to occasionally causing infections in humans, can also serve as a source of resistance and virulence genes for strains of greater importance in human medicine, such as Staphylococcus aureus. Furthermore, MRSP strains are often multidrug resistant, which ends up compromising the treatment of infections. This study aimed to assess the potential transmission of Staphylococcus pseudintermedius among dogs and their owners. We examined a total of one hundred canine samples collected from cases of pyoderma and otitis to detect the presence of staphylococci. Simultaneously, we conducted evaluations on all dog owners. Staphylococci strains were identified using MALDI-TOF MS and PCR targeting the nuc gene. Methicillin resistance screening was also performed by detecting the mecA gene using PCR. Among the sampled dogs, 64 carried S. pseudintermedius. Nine were identified as MRSP. In six instances, dogs and their owners exhibited S. pseudintermedius. These samples underwent genome sequencing and were screened for antimicrobial resistance genes, SCCmec typing, MLST characterization, and Single Nucleotide Polymorphisms (SNP) analyses. The results of the phylogenetic analysis revealed that in three cases, dogs and owners had closely related isolates, suggesting interspecies transmission. Two of these cases involved MRSP and one MSSP. Moreover, in the two MRSP cases, the same SCCmec type (type V) was detected. Additionally, the sequence type was consistent across all three cases involving dogs and owners (MSSP ST2277, MRSP ST2282, and ST2286). These findings strongly indicate a transmission event. Since Staphylococcus pseudintermedius is primarily isolated from canine samples, it is plausible that dogs may have acted as a potential source. In the remaining three cases, despite identifying the same species in both samples, they had notable phylogenetic differences.

Chlamydia psittaci is the causative agent of psittacosis in humans, while its rapid identification is hampered due to the lack of specificity of laboratory testing methods.
This study reports four cases of C. psittaci infection after contact with a domestic parrot, all belonging to the same family. Common manifestations like fever, cough, headache, nausea, and hypodynamia appeared in the patients. Metagenomic next-generation sequencing (mNGS) aided the etiological diagnosis of psittacosis, revealing 58318 and 7 sequence reads corresponding to C. psittaci in two cases. The detected C. psittaci was typed as ST100001 in the Multilocus-sequence typing (MLST) system, a novel strain initially reported. Based on the results of pathogenic identification by mNGS, the four patients were individually, treated with different antibiotics, and discharged with favorable outcomes.
In diagnosing psittacosis caused by a rare C. psittaci agent, mNGS provides rapid etiological identification, contributing to targeted antibiotic therapy and favorable outcomes. This study also reminds clinicians to raise awareness of psittacosis when encountering family members with a fever of unknown origin.

BACKGROUND: Investigation of risk factors for the presence of vancomycin-resistant enterococci (VRE) in inpatients on surgical wards and associated intensive care units of a German tertiary care hospital.
METHODS: A single-centre retrospective matched case-control study was performed with surgical inpatients admitted between July 2013 and December 2016. Patients with in-hospital detection of VRE later than 48 h after admission were included and comprised 116 VRE-positive cases and 116 VRE-negative matched controls. VRE isolates of cases were typed by multi-locus sequence typing.
RESULTS: ST117 was identified as the dominant VRE sequence type. Next to length of stay in hospital or on an intensive care unit and previous dialysis the case-control study revealed previous antibiotic therapy as a risk factor for the in-hospital detection of VRE. The antibiotics piperacillin/tazobactam, meropenem, and vancomycin were associated with the highest risks. After taking into account length of stay in hospital as possible confounder other potential contact-related risk factors such as previous sonography, radiology, central venous catheter, and endoscopy were not significant.
CONCLUSIONS: Previous dialysis and previous antibiotic therapy were identified as independent risk factors for the presence of VRE in surgical inpatients.

BACKGROUND: Enteric fever is an acute systemic infectious disease associated with substantial morbidity and mortality in low- and middle-income countries (LMIC), with a global burden of 14.3 million cases. Cases of enteric fever or paratyphoid fever, caused by Salmonella enterica serovar Paratyphi A (S. Para A) have been found to rise in many endemic and non-endemic countries. Drug resistance is relatively uncommon in S. Para A. Here we report a case of paratyphoid fever caused by ceftriaxone resistant S. Para A from Pakistan.
METHODS: A 29-year-old female presented with a history of fever, headache, and shivering. Her blood culture revealed a S. Para A isolate (S7), which was resistant to ceftriaxone, cefixime, ampicillin and ciprofloxacin. She was prescribed oral Azithromycin for 10 days, which resulted in resolution of her symptoms. Two other isolates of S. Para A (S1 and S4), resistant to fluoroquinolone were also selected for comparison. DST and whole genome sequencing was performed for all three isolates. Sequence analysis was performed for identification of drug resistance and phylogeny. Whole Genome Sequencing (WGS) of S7 revealed the presence of plasmids, IncX4 and IncFIB(K). blaCTX-M-15 and qnrS1 genes were found on IncFIB(K). The gyrA S83F mutation conferring fluoroquinolone resistance was also found present. Multi-locus sequence typing (MLST) showed the S7 isolate to belong to ST129. S1 and S4 had the gyrA S83Y and S83F mutations respectively.
CONCLUSIONS: We highlight the occurrence of plasmid-mediated ceftriaxone resistant strain of S. Para A. This is of significance as ceftriaxone is commonly used to treat paratyphoid fever and resistance in S. Para A is not known. Continuous epidemiological surveillance is required to monitor the transmission and spread of antimicrobial resistance (AMR) among Typhoidal Salmonellae. This will guide treatment options and preventive measures including the need for vaccination against S. Para A in the region.

Introduction. Invasive meningococcal disease (IMD) caused by Neisseria meningitidis may show temporal and geographical changes in both the epidemiology and the characteristics of the strains involved.Gap statement. A study that examined invasive N. meningitidis causing IMD in Atlantic Canada from 2009 to 2013 was published in 2014. Data from subsequent years have not been described.Aim. This study examined the molecular epidemiology of IMD in four Atlantic Provinces of Canada as well as potential serogroup B (MenB) vaccine coverage.Methods. Individual IMD case isolates recovered from 2014 to 2020 were analysed for serotype and serosubtype antigens as well as by whole-genome sequencing (WGS) for prediction of potential MenB vaccine coverage.Results. Of the 56 IMD isolates, 42, 8, 5 and 1 were MenB, serogroup Y, serogroup W (MenW) and serogroup C, respectively. Geographical differences in the distribution of MenB clones revealed concentration of sequence type (ST)-269 clonal complex (cc) and ST-60 cc in Newfoundland and Labrador, while ST-41/44 cc (particularly ST-154) was predominantly found in New Brunswick and Nova Scotia. Core genome multi-locus sequence typing (cgMLST) also separated the New Brunswick and Nova Scotia ST-154 isolates into two clusters, with differences in their nhba and penA alleles. Furthermore, cgMLST also separated the ST-269 cc isolates in Atlantic Canada into the ST-1611 and the ST-269/ST-8924 clusters, with the latter showing high similarity to the ST-269 that first emerged in the Province of Quebec. Genetic Meningococcal Antigen Typing System showed that 54.8 % of MenB were predicted to be covered by the MenB vaccine Bexsero, with a further 38.1 % potentially covered by virtue of the presence of genes that encoded factor H-binding protein variant 1 proteins. Meningococcal deduced vaccine antigen reactivity predicted from WGS data showed that 95.3 % of MenB were covered by Trumenba. Four cases of IMD due to MenW ST-11 cc were also identified, with the first case found in 2018.Conclusions. This study provided evidence concerning the dynamics of N. meningitidis strains causing IMD in Atlantic Canada, with both geographical and temporal differences found. MenB vaccine appeared to provide good coverage of MenB IMD, especially towards the predominant strain of ST-154.

In recent years, the incidence of pediatric septic arthritis caused by Streptococcus pneumoniae has been quite low. The pneumococcal conjugate vaccine PCV10 is the available vaccine included in the Bulgarian national immunization program. PCV10 reduces the incidence of invasive diseases, but non-vaccinal serotypes like 19A, the etiologic agent of the case of septic arthritis reported herein in a 3-year-old boy. The synovial fluid was positive for S. pneumoniae. The patient was treated with vancomycin during hospitalization and trimethoprim/sulfamethoxazole was recommended for at-home treatment. The isolate was subjected to latex agglutination, antimicrobial susceptibility testing, PCR detection for macrolide-resistance genes, and MLST. The strain revealed ST695 and a genotype previously associated with vaccine serotype 4. The incidence of pneumococcal infections caused by capsule-switching events and non-PCV10 serotypes is expected to increase.

Despite the worldwide use of 16S rRNA to identify bacterial species, the use of this gene does not discriminate the 750 species in the genus Streptomyces. A MLST scheme was constructed with rpoB, gyrB, recA, trpB and atpD genes to access the genomic variances in Streptomyces species evolution. We analyze the housekeeping genes in 49 Streptomyces isolates from Antarctic soil. It was used two different databases, GenBank and EzBioCloud to compare the 16S sequences. The species founded in both databases are not the same, but in both cases, a few isolates achieve the necessary high percentage to consider the identification. There is a lack of deposited sequences in the other genes, as the data in GenBank proved to be insufficient. Isolate LMA323St_9 has the potential to be studied as a novel species. Besides that, the use of housekeeping genes gives robust phylogenetic information to understand in group relationships.

Leptospirosis is a bacterial zoonosis that occurs in tropical and subtropical regions worldwide. Chiroptera are known to be a formidable reservoir of zoonotic pathogens, including leptospires. The epidemiology of leptospirosis in bats in the Pacific Islands is poorly known, both in terms of prevalence and in terms of the bacterial strains involved. A strong host specificity between leptospiral strains and their mammalian reservoir is recognized. This phenomenon has notably been studied recently in bat communities, providing strong evidence of co-evolution. In New Caledonia, a biodiversity hotspot where leptospirosis is endemic and enzootic, Chiroptera are the only indigenous terrestrial mammals. In this study, we aimed to investigate leptospires associated with three flying fox species in New Caledonia. Kidneys and urine samples of Pteropus spp. from captures and seizures were analysed. Among 254 flying foxes analysed, 24 harboured pathogenic leptospires corresponding to an observed prevalence of 9.45% with 15.8% on the Main Island and 4.3% on Loyalty Islands. The analysis of the rrs gene, lfb1, and MLST sequences evidenced four distinct clusters of undescribed strains, likely corresponding to undescribed species. All four strains belong to the Group I of pathogenic Leptospira spp., which includes Leptospira interrogans, Leptospira noguchii, and Leptospira kirschneri. We detected pathogenic leptospires in all three Pteropus spp. studied (including two endemic species) with no evidence of host specificity in two co-roosting species. For a better understanding of Leptospira-host co-evolution, notably to genetically characterize and evaluate the virulence of these original bat-associated leptospires, it is essential to improve isolation techniques. Flying foxes are traditionally hunted and eaten in New Caledonia, a massive cause of bat-human interactions. Our results should encourage vigilance during these contacts to limit the spillover risk of these pathogens to humans.