Phenotypic and genotypic characterization of plasmid-mediated AmpC beta-lactamases in enteric Gram-negative bacteria from patients with lower respiratory tract infections in a tertiary hospital, southwest Nigeria

Background: AmpC or class C or group 1 beta lactamases are class C cephalosporinases that hydrolyse a wide variety of beta-lactam antibiotics including alpha methoxy beta-lactams (cefoxitin), narrow and broad spectrum cephalosporins. This study was conducted to characterize plasmid-mediated AmpC producing enteric Gram- negative bacteria from patients with lower respiratory tract infections in Obafemi Awolowo University Teaching Hospital Complex (OAUTHC) Ile Ife, Osun State, NigeriaMethodology: A total of 149 patients with clinical features of lower respiratory tract infections (LRTI) were selected by simple random sampling for the study. All Gram-negative isolates recovered from standard microbiological cultures of respiratory specimens of these patients were tested against cefoxitin, third generation cephalosporins (3GCs), and other antibiotics using the disc diffusion AST method, and also screened for production of AmpC beta-lactamases phenotypically by the CLSI method. Plasmid DNA extraction was carried out on twenty-nine cefoxitin-resistant selected isolates using the Kado and Lin method, while genotypic detection of plasmid-mediated AmpC gene was carried out by the polymerase chain reaction (PCR) assay.Results: The results showed that 204 (43.3%) of 471 isolates recovered from the 149 selected patients were resistant to 3GC in the AST assay, among which 121 (59.3%) were resistant to cefoxitin, and 189 of the 471 isolates (40.1%) were AmpC producers. The AmpC producers concurrently showed multiple resistance pattern to other antibiotics tested in this study. Ninety six percent of the 29 selected isolates for plasmid analysis contained plasmids, 45% of which amplified positive on PCR for CMY, 38% for FOX, and 31% for ACC types of AmpC genes.Conclusion: This study showed a high degree of antibiotic resistance among enteric Gram-negative bacteria recovered from patients with LRTIs, as well as high degree of plasmid-encoded AmpC genes responsible for this high antibiotic resistance among the isolates. Proper antibiotic policy and regulation are required to limit the spread of plasmid mediated AmpC β-lactamase producing organisms because they can lead to therapeutic failure in infected patients in the nearest future.   French title: Caractérisation phénotypique et génotypique des bêta-lactamases AmpC à médiation plasmidique dans les bactéries entériques Gram-négatives de patients atteints d'infections des voies respiratoires inférieures dans un hôpital tertiaire, sud-ouest du Nigéria Contexte: Les bêta-lactamases AmpC ou de classe C ou de groupe 1 sont des céphalosporinases de classe C qui hydrolysent une grande variété d'antibiotiques bêta-lactamines, y compris les alpha-méthoxy bêta-lactamines (céfoxitine), les céphalosporines à spectre étroit et large. Cette étude a été menée pour caractériser les bactéries à Gram négatif entériques produisant de l'AmpC à médiation plasmidique chez des patients atteints d'infections des voies respiratoires inférieures du complexe hospitalier universitaire d'Obafemi Awolowo (OAUTHC) Ile Ife, État d'Osun, NigériaMéthodologie: Un total de 149 patients présentant des caractéristiques cliniques d'infections des voies respiratoires inférieures (LRTI) ont été sélectionnés par échantillonnage aléatoire simple pour l'étude. Tous les isolats à Gram négatif récupérés à partir de cultures microbiologique standard d'échantillons respiratoires de ces patients ont été testés contre la céfoxitine, les céphalosporines de troisième génération (3GC) et d'autres antibiotiques en utilisant la méthode AST de diffusion sur disque, et également criblés pour la production de bêtalactamases AmpC phénotypiquement par le Méthode CLSI. L'extraction de l'ADN plasmidique a été réalisée sur 29 isolats sélectionnés résistants à la céfoxitine en utilisant la méthode Kado et Lin, tandis que la détection  génotypique du gène AmpC à médiation plasmidique a été réalisée par le test de réaction en chaîne par polymérase (PCR).Résultats: Les résultats ont montré que 204 (43,3%) des 471 isolats récupérés des 149 patients sélectionnés étaient résistants à la 3GC dans le test AST, parmi lesquels 121 (59,3%) étaient résistants à la céfoxitine et 189 des 471 isolats (40,1%) étaient des producteurs d'AmpC. Les producteurs d'AmpC ont montré simultanément plusieurs profils de résistance à d'autres antibiotiques testés dans cette étude. Quatre-vingt-seize pour cent des 29 isolats sélectionnés pour l'analyse des plasmides contenaient des plasmides, dont 45%  amplifiés positifs par PCR pour CMY, 38% pour FOX et 31% pour les types ACC des gènes AmpC.Conclusion: Cette étude a montré un degré élevé de résistance aux antibiotiques parmi les bactéries entériques Gram-négatives  récupérées chez des patients atteints de LRTI, ainsi qu'un degré élevé de gènes AmpC codés par plasmide responsable de cette résistance élevée aux antibiotiques parmi les isolats. Une politique et une réglementation appropriées en matière d'antibiotiques sont nécessaires pour limiter la propagation des organismes producteurs β-lactamase d'AmpC à médiation plasmidique car ils peuvent conduire à un échec thérapeutique chez les patients infectés dans un avenir proche. &nbsp

Earring aspiration in a toddler: A case report

Aspiration of foreign body is not an uncommon life-threatening emergency in pediatric practice. Objects that are commonly aspirated include nuts, beans, toys, and in very rare instances jewelries among others. This is a 2 year old female toddler who presented in our facility on account of sudden onset of cough which became recurrent with associated difficulty with breathing of one month duration. Symptoms were first observed immediately after she was noticed to have aspirated a piece of her rigid earrings that was left on a table at home. She had chest x-ray that showed evidence of an opaque foreign body in the left main bronchus for which she had fluoroscopy guided bronchoscopy with removal of a rigid metallic earring. The patient was subsequently discharged on the second day post-operation. Earring aspiration is uncommon in children, but when it occurs it could result in grave consequences. Parents and guardians should suspect possibility of such aspiration if there is a missing earring belonging to a child who has sudden onset of respiratory difficulty

Clinical neglect of aspergillosis in pulmonary tuberculosis coinfection: a case report of avoidable mortality in a resourceconstrained setting

Background: Pulmonary aspergillosis (PA) is common among patients with tuberculosis (TB). With both infections presenting with similar clinical and radiologic features, diagnosis of PA is often made too late or missed completely due to lack of clinical suspicion and poor diagnostic laboratory  capacity for mycotic infections prevalent in our settings. We present a case of preventable mortality caused by delayed diagnosis and treatment of  PA in a patient with pulmonary TB (PTB). Case presentation: A 13-year-old female was diagnosed and treated for PTB, having received anti-TB regimen for 8 months in a mission hospital  from where she was referred due to worsening cough, chest pain and progressive breathlessness. The patient was re-assessed and investigated,  with GeneXpert detecting Mycobacterium tuberculosis, susceptible to rifampicin. Diagnosis of pulmonary tuberculosis complicated by right  pneumothorax was made indicating an emergency thoracotomy and chest tube insertion and continuation of the first line anti-TB regimen. At about  2 weeks into admission, patients had features of superimposed acute bacterial sepsis with fever becoming high grade, marked neutrophilia  with toxic granulation and elevated sepsis biomarker, and this necessitated empiric antibiotic treatment with parenteral meropenem and  vancomycin. However, the patient only had mild clinical improvement following which there was progressively worsening respiratory symptoms and  massive haemoptysis. Result of sputum fungal study was available on admission day 20 and revealed a growth of Aspergillus flavus. Treatment with  intravenous voriconazole was however commenced rather late when the fungal respiratory disease could no longer be remedied. The patient died  on admission day 23. Conclusion: Diagnosis of PA in patients with background TB is often made too late to guarantee timely and effective  antifungal treatment with negative consequences on patients’ outcomes. Improving clinical and laboratory capacities is essential to reducing  mortality from PA in healthcare facilities