Carbapenems are among the antibiotics of last resort against infections caused by antibiotic resistant bacteria. However, resistance to this important class of antibiotic is on the increase due to expression of metallo-betalactamases (MBLs). This study investigated the occurrence of MBL-producing bacteria in a healthcare facility in Sokoto, Nigeria. Swabs were collected from the rectum (n = 29) and bed linens (n = 27) of patients within the surgical wards of the hospital between March and August, 2018 and processed using Centers for Disease Control and Prevention (CDC) broth enrichment method for isolation of carbapenem resistant Gram-negative bacteria (CR-GNB). In addition, 110 bacteria isolated from clinical specimens submitted to microbiology laboratory of the hospital were collected and tested for susceptibility to antibiotics using the disc diffusion method. The carbapenem resistant isolates were further evaluated for MBL-production using the combined disc method. Overall, 31(28.2%) of the Gram-negative bacterial isolates were carbapenem resistant. The most predominant isolated bacterium in this study was E. coli (18; 36%). The isolates were highly resistant to cephalosporins (74%) and fluoroquinolones (52.7%) while remaining moderately susceptible to gentamicin (38.8%) and amoxicillin-clavulanate (45.7 %). Majority of the CR-GNB were extensively drug resistant (19; 38%) and pan drug resistant (10; 20%). The MBL-production test revealed that 19 (38.0%) of the CR-GNB were MBL-positive. The study revealed a high prevalence of MBL-producing CR-GNB in a hospital with no history of its use. This report documents for the first time the independent emergence of such resistance in our hospital. Implementation of adequate antibiotic stewardship program is therefore imperative so as to contain this emerging threat.

This paper presents a novel method for estimating reverberation time in an enclosed space by analyzing the energy decay curve. Reverberation time (RT) is a key parameter to determine the acoustic of a room and it provides an information about the quality and intelligibility of sound in an enclosure. RT can be determine directly from room acoustics, but in case where this is difficult to determine, it is estimated blindly from the reverberation speech. Blind reverberation time (BRT) is a method of measuring the reverberation time of a room without the use of any external equipment. It is based on the human auditory system's ability to detect and measure the decay of sound and acoustic properties of a room, which can be used to determine how suitable it is for certain activities, such as music or speech. In this study, we provide a study/comparison of two methods for BRT estimation. Data were collected from relevant papers as cited. Comparison of the two methods are carried out in terms of estimation error and effect on signal-to-noise ratio (SNR). The methods were able to estimates the RT within 0.2sec for RT ≤ 0.8sec and SNR ≥ 10dB. Thus, the key effect of additive noise on all methods is a positive bias of the estimation error which results in estimation error of e ≥ 0.2sec, which is an over-estimation. The results obtained shows that the methods can be used to accurately compare the reverberation time in an enclosed space with minimal effort.