- Volume 5, Issue 6, 2023

Bacteria resistant to antibiotics arguably pose the greatest threat to human health in the twenty-first century. One such bacterium that typifies antibiotic resistance is Acinetobacter baumannii . Frequently, hospital strains of A. baumannii display multidrug resistant (MDR) or extensively drug resistant (XDR) phenotypes, often requiring the use of last resort antibiotics for treatment. In addition to hospital settings, A. baumannii has been isolated from many highly divergent sources including wastewater treatment plant effluent, soil, and agricultural run-off with global distribution. However, such isolates remain poorly characterized. In this study, we characterized a strain of A. baumannii, AB341-IK15, isolated from bulk tank milk in Germany that demonstrated resistance to ceftazidime and intermediate resistance to ceftriaxone and piperacillin/tazobactam. Further genetic characterization identified an ADC-5 cephalosporinase, first incidence in an environmental isolate; and an OXA-408 oxacillinase that may contribute to this phenotype. Interestingly, AB341-IK15 is of a novel sequence type. This research underscores the importance of studying isolates of A. baumannii of non-clinical origin to understand the antibiotic resistance and virulence potential of environmental isolates of A. baumannii as well to understand the diversity of this species.

A card game called BactoBattle has been developed to help medical students who have just started learning medical bacteriology to improve their learning efficacy and satisfaction, especially on the topic of antimicrobial resistance. Copies of the game were placed in the students’ study room (approximately 1 set per 12 students) and made available to the students throughout the study period so that they could choose to play the game during their free time if desired. After the study period had ended, the students were asked to complete a questionnaire and a post-test. In total, 33 students completed the questionnaire, and were split into 2 groups: the player group, comprising 12 (36.4 %) students who had played the game, and the non-player group. The player group perceived that they could memorize more knowledge compared to the non-player group and indeed recorded higher post-test scores than the non-player group (10.4 vs 8.3 out of 15 points, P=0.031). However, there was no difference in learning motivation (P=0.441) or enjoyment (P=0.562) between the two groups. A majority of the players said they would continue playing the game after the study period and would recommend the game to other students. In short, the BactoBattle game can be a useful tool to improve the learning efficacy of students, but its effect on learning satisfaction remains unclear.

Introduction. Pseudomonas citronellolis is an unusual pathogen in humans and has not been extensively described in the scientific literature. Herein, we present a case of bacteremia and septic shock due to Pseudomonas citronellolis following Campylobacter species gastroenteritis in a patient with immunosuppression.

Case Presentation. An 80-year-old man with myeloproliferative disorder on ruxolitinib presented with several days of worsening abdominal pain, which rapidly developed into septic shock with multi-organ failure and explosive diarrhea. Gram-negative bacilli observed on Gram staining of his blood culture broth were later identified as Pseudomonas citronellolis and Bacteroides thetaiotaomicron . Repeated abdominal imaging revealed no evidence of intestinal perforation or megacolon. In addition, stool PCR was positive for Campylobacter species. His clinical course improved after 14 days of meropenem with complete resolution of his symptoms and organ failure.

Conclusion. P. citronellolis is a rare infection in humans. We postulate that Janus Associated Kinase (JAK) inhibition in myeloproliferative disorders heightened this patient’s risk of bacterial translocation and severe illness in the setting of Campylobacter gastroenteritis. P. citronellolis may be identified more frequently as a pathogen in humans as more advanced diagnostic technologies become increasingly available in clinical microbiology.

Introduction. Carbapenems are usually used in the treatment of infections caused by cephalosporin-resistant Enterobacterales ; however, the increase in carbapenem-resistant Enterobacterales (CRE) has become one of the most important problems in public health. Hafnia alvei is associated with intestinal and extraintestinal infections, especially in patients with any chronic disease or some type of immunosupression. H. alvei is resistant to first-generation aminopenicillins and cephalosporins owing to the β-lactamase (Amp C) in their chromosome; the only carbapenem-resistant Hafnia strain described until now was due to a lack of the OmpK36 protein that plays an important role in permeability to carbapenems.

Case presentation. We present the case of a 65-year-old male diagnosed with acute lithiasic cholecystitis. Culture of the biliary prosthesis yielded a OXA-48-producing H. alvei that was identified by MALDI-TOF (matrix-assisted laser desorption/ionization-time of flight) MS. Carbapenemase production was detected by immunochromatography and confirmed by sequencing.

Conclusion. To our knowledge, this is the first report of OXA-48-producing H. alvei probably obtained by horizontal transfer from Enterobacter cloacae OXA-48 isolated in previous samples.

Introduction. Paenibacillus species are saprophytes widely distributed in nature and rarely associated with overt human infection. Most cases have been described in people with important comorbidities and/or immunodepression. We report here what is, to the best of our knowledge, the first documented case of human disease due to Paenibacillus silvae , so far considered an exclusively environmental micro-organism.

Case presentation. A 57-year-old female patient was referred to our Unit after a 2 month history of remittent fever. Upon admission, a septic state and bacteraemia were revealed; P. sylvae was identified by 16S rRNA gene amplification and sequencing with matrix-assisted laser desorption/ionization-time of flight MS. The patient became afebrile after 9 days of antibiotic treatment and was completely cured after a 2 week regimen with intravenous amoxicillin-clavulanate plus oral doxycycline.

Conclusion. The patient did not report any previous episode of infection. Most of the well-known risk factors to Paenibacillus bacteraemia, i.e. invasive procedures, use of intravenous drugs and foreign bodies, could be excluded, although her immune system was probably impaired due to obesity and heavy smoking. We suggest that the isolation of bacteria belonging to the genus Paenibacillus should not be disregarded, since there is accumulating evidence that these organisms may cause disease even in immunocompetent subjects.

Introduction. Brain abscess is the most common focal infectious neurological injury. Until the nineteenth century this condition was fatal, however the development of neuroimaging for early diagnosis, neurosurgery and antibiotic therapy in the twentieth century has led to new therapeutic strategies decreasing mortality from 50 % in the 1970s to less than 10 % nowadays. In this context we report a case of brain abscess with a dental origin.

Case report. A immunocompetent man without any addiction presented to the emergency department with dysarthria and frontal headache at home. The clinical examination was normal. Further investigations revealed a polymicrobial brain abscess as a consequence of an ear, nose or throat (ENT) infection with locoregional extension with a dental starting point involving Actinomyces israelii and Fusobacterium nucleatum . In spite of a rapid diagnosis and a neurosurgical management associated with an optimal treatment by a dual therapy made of ceftriaxone and metronidazole the patient unfortunately died.

Conclusion. This case report shows that despite a low incidence and a good prognosis following the diagnosis, brain abscesses can lead to patient’s death. Thereby, when the patient’s condition and urgency allow, a thorough dental examination of patients with neurological signs following the recommendations would improve the diagnosis made by the clinician. The use of microbiological documentation, the respect of pre-analytical conditions, the interaction between the laboratory and the clinicians are indispensable for an optimal management of these pathologies.

Introduction. Although rare, human infections caused by Gordonia spp. have been reported, especially within the immunocompromised population and those with long-term indwelling devices. We report a case of Gordonia spp. bacteraemia in a renal transplant patient and present a literature review on microbiological identification methods of this organism.

Case Presentation. A 62-year-old female renal transplant recipient admitted to hospital with a 2-month history of dry cough and fevers occurring weekly when receiving electrolyte replacement infusions via a Groshong line. Over 2 weeks, blood cultures repeatedly isolated a Gram-positive bacillus solely in aerobic bottles, and this was initially reported as Rhodococcus spp. by the local microbiology laboratory. Chest computed tomography (CT) showed multiple ground-glass lung opacities suggestive of septic pulmonary emboli. As central line-associated bloodstream infection was suspected, empirical antibiotics were initiated and the Groshong line was removed. The Gram-positive bacillus was later confirmed by the reference laboratory as Gordonia sputi via 16S rRNA sequencing. Vancomycin and ciprofloxacin for a duration of 6 weeks were completed as targeted antimicrobial therapy. After treatment, the patient remained symptom-free with marked improvement on repeat CT chest imaging.

Conclusion. This case illustrates the challenges surrounding identification of Gordonia spp. and other aerobic actinomycetes. 16S rRNA gene sequencing may be a preferred identification method, especially when initial workup of a weakly acid-fast organism fails to make an identification or shows discrepant results using traditional diagnostic modalities.

Background. The microbial infection of the endocardium, popularly known as Infective Endocarditis (IE), is typically classified on the basis of anatomy, valve nativity and its associated microbiology. As per the associated microbiology, Staphylococcus aureus is the most common microorganism responsible for the cause of IE. Even though, the Streptococcus group accounts for a smaller percentage of IE, however this doesn’t give us the liberty of ignoring the high mortality and morbidity associated with this pathogen.

Case presentation. We report an unusual case of neonatal sepsis, complicated with endocarditis, caused by penicillin resistant Streptococcus parasanguinis . The neonate however died of the same despite all efforts. The said baby was given birth by a mother with gestational diabetes mellitus.

Conclusion. High index of clinical suspicion and prompt diagnosis are the most important factors of patient management, especially in cases of life threatening neonatal infections. In such conditions a coordinated interdepartmental approach is very much needed.

Ruminococcus gnavus , a Gram-positive anaerobic coccus, is a common constituent of the human gut microbiota but rarely causes any disease in humans. Herein, we report a case of R. gnavus bacteraemia in an immunocompromised 73-year-old man with sigmoid colon perforation. R. gnavus is usually reported as Gram-positive diplococci or short chains on Gram staining; however, in our patient, a blood isolate showed Gram-positive cocci in long chains, and organisms from an anaerobic subculture showed morphological diversity. This case provides insight into the morphological diversity of R. gnavus , which might help with the recognition of these bacteria in the preliminary identification stage on Gram staining.

The coronavirus disease 2019 (COVID-19) pandemic has manifested as a multifaceted paradigm but has primarily affected the respiratory system. Though a rare sequela after-COVID-19, we present a case of cavitary lung lesion in an adult patient, which manifested with common symptoms such as fever, cough and dyspnoea during the post-COVID-19 recovery period. Aspergillus flavus and Enterobacter cloacae were found to be the main causative organisms. Fungal and bacterial coinfection may be thought of in similar situations and appropriate treatment may be given to prevent further morbidity and mortality.