The effect of a post-anaesthesia high-care unit (PAHCU) admission on mobilization, length of stay and in-hospital mortality post-surgery in low energy neck of femur fracture patients.

PURPOSE/AIM: With an ageing population and an increase in fragility fractures of the hip (FFH), the role of an anaesthetist is evolving to include more peri-operative care. A post-anaesthesia high-care unit (PAHCU) should enhance care in post-operative patients. To our knowledge, there are no studies that have investigated the effect of a PAHCU admission on post-operative outcomes after FFH. This study aimed to compare post-operative outcomes of FFH patients admitted to PAHCU versus a standard post-operative orthopaedic ward (POOW). METHODOLOGY: A retrospective cohort study was conducted on adult patients with FFH who underwent surgery between January 2019 and December 2020 at our institution. Data were sourced from electronic medical records. SPSS version 28 was used to analyse data. RESULTS: A total of 231 patients were included. The PAHCU group (n = 35) displayed a higher burden of chronic illness and higher peri-operative risk scores as compared to the POOW group (n = 196). Median time to mobilize (TTM) in PAHCU was 84 h vs. 45 h in POOW group (p = 0.013). Median length of stay (LOS) in PAHCU was 133 h vs. 94 h in POOW (p = 0.001). The in-hospital mortality was 2.9% (n = 1) for PAHCU and 3.6% (n = 7) for POOW (p = 1). The 30-day mortality was 11.8% (n = 4) for PAHCU and 10.1% (n = 19) in POOW. CONCLUSION: PAHCU admission resulted in delayed time to surgery and TTM, together with prolonged LOS, compared to those managed in POOW. However, these mortality rates remained comparable in both groups. This study contributes valuable insights into post-operative care of FFH patients in a resource-poor setting.

Relevance of prokaryotic subspecies in the age of genomics.

The availability of multiple gene sequences, and in particular full genome sequence data, for microbial strains has changed how taxonomists delineate subspecies belonging to the Archaea and Bacteria. Well-defined phylogenetic lineages that share higher genome similarity values compared to the widely used species thresholds are often described as subspecies, despite clear evidence of genetic isolation between them. These well-defined lineages, reflecting notable genetic isolation of the core genome represent more recently evolved, unique and sui generis evolutionary units. Because they bear all of the hallmarks of species, most contemporary subspecies likely represent species in their own right. Although there is considerable value in defining intraspecies variation (e.g., pathovar, serovar and symbiovar), the discriminating properties of such units are mostly encoded on accessory subgenomic compartments. We therefore argue that the taxonomic category of subspecies has become irrelevant and propose that its use should be discontinued. This will minimize inconsistencies related to the subjective nature of species-subspecies distinctions. Formal recognition of biologically relevant variation within species based on the accessory genome information will have practical significance in fields such as clinical, industrial and agricultural microbiology.

It is time for a new type of type to facilitate naming the microbial world.

Since January 1, 2001, the only acceptable nomenclatural type for species under the International Code of Nomenclature of Prokaryotes (ICNP) has been pure cultures. Here, we argue that this requirement is discordant with the more inclusive nature of nomenclatural types accepted under other codes of nomenclature and posit that the unique rigidity of the ICNP has failed to serve the broad research community and has stifled progress. This case is based on the axiom that many archaea and bacteria are interdependent in nature and therefore difficult, if not impossible, to grow, preserve, and distribute as pure cultures. As such, a large proportion of Earth's biodiversity cannot be named under the current system, which limits our ability to communicate about microbial diversity within and beyond the microbiology research community. Genome sequence data are now encouraged for valid publication of new taxa in microbial systematics journals, and metagenome-assembled genomes and single cell-amplified genomes are being generated rapidly from every biome on Earth. Thus, genome sequences are available for both cultivated and uncultivated microorganisms and can readily serve as a new category of nomenclatural type, allowing for a unified nomenclature for all archaea and bacteria, whether or not they are available as pure cultures. Ideally this would be under a single code of nomenclature but, as we review here, the newly established SeqCode will operate in parallel with the ICNP as a first step toward this goal.

Magnetotactic bacteria used to generate electricity based on Faraday's law of electromagnetic induction.

Magnetotactic bacteria (MTB) have the unique ability to produce magnetic particles surrounded by a biomembrane to form the magnetosome organelle. Therefore, MTB have novel physical and magnetic properties and have consequently been used in several biotechnological applications. The magnetic properties of these micro-organisms and their magnetosomes have, however, never been used for the generation of electricity as described in this letter. Comparisons were made between, firstly, the electricity generated from purified magnetosomes, MTB culture (bacterial cells with magnetosomes) and sterile, liquid growth medium (control). Secondly, the electricity generated by a dilution series of purified magnetosomes were compared. A statistically significant difference was found between the voltage measured from the purified magnetosomes (highest voltage), MTB culture (lower voltage) and liquid growth medium (lowest voltage). In the dilution series, the voltage measured increased as the magnetosome concentration increased, but only up to an optimum concentration (0·0376 mg ml-1 ). In this study, we have demonstrated that a significantly higher voltage than that of the control could be measured when MTB or purified magnetosomes were pumped through a solenoid by applying Faraday's law of electromagnetic induction. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides proof-of-concept of electromagnetic induction using magnetosomes or magnetotactic bacteria in an experimental setup based on the law of Faraday. The concept of using these bacteria or their biomineralized magnetic nanoparticles as a biological alternative in low voltage electricity generation has the potential to be further explored and developed.

The prevalence, risk factors predicting injury and the severity of injuries sustained during competition in professional mixed martial arts in Africa

Background: Professional mixed martial arts (MMA) has gained international popularity. No African-based studies have reported the prevalence or severity of injuries, risk factors associated with injuries or return-to-play (RTP) time. Objectives: To determine the prevalence of injuries and associated risk factors, as well as severity of injuries sustained by professional male MMA athletes competing at the Extreme Fighting Championships Africa (EFC Africa) from 2010 to 2014.Methods: Permission to do the study and the medical records of all professional events (2010 ­ 2014) were obtained from EFC Africa. Data were obtained from 173 male competitors aged 18 to 44 years, who had participated in 300 professional MMA fights. Results from this prospective cohort study were compared to a similar study done in the United States of America (USA). An injury was defined as any damage to an athlete's body that needed the attention of the ringside physician. Statistical analyses included descriptive statistics and a stepwise logistic regression. Odds of an injury were predicted with six independent variables: fight outcome, age, weight division, number of fights, injuries in the preceding fight and years of fighter experience.Results: Head, face and neck injuries were most common (22%), followed by traumatic brain injuries (knockouts) (6%). Losing a fight was a significant predictor of injury when using the stepwise logistic regression model (p=0.040). The odds ratio indicated that a preceding fight injury almost doubled the risk of injury in the following fight (OR 1.91; p= 0.163). Traumatic brain injuries (TBIs) in this study of African-based competitions (6%) were substantially higher than reported in the American study (1.8%). Conclusion: Head, neck and face injuries are common in African fighters. The high rate of TBIs in African competition compared to the USA study is concerning. This could reflect superior refereeing in the USA group, as fights may be ended sooner by stoppage. Further investigation of injury trends and preventative measures should be studied to reduce the incidence of injuries during African competitions

Fate of Salmonella Typhimurium in laboratory-scale drinking water biofilms.

Investigations were carried out to evaluate and quantify colonization of laboratory-scale drinking water biofilms by a chromosomally green fluorescent protein (gfp)-tagged strain of Salmonella Typhimurium. Gfp encodes the green fluorescent protein and thus allows in situ detection of undisturbed cells and is ideally suited for monitoring Salmonella in biofilms. The fate and persistence of non-typhoidal Salmonella in simulated drinking water biofilms was investigated. The ability of Salmonella to form biofilms in monoculture and the fate and persistence of Salmonella in a mixed aquatic biofilm was examined. In monoculture S. Typhimurium formed loosely structured biofilms. Salmonella colonized established multi-species drinking water biofilms within 24 hours, forming micro-colonies within the biofilm. S. Typhimurium was also released at high levels from the drinking water-associated biofilm into the water passing through the system. This indicated that Salmonella could enter into, survive and grow within, and be released from a drinking water biofilm. The ability of Salmonella to survive and persist in a drinking water biofilm, and be released at high levels into the flow for recolonization elsewhere, indicates the potential for a persistent health risk to consumers once a network becomes contaminated with this bacterium.

Isolation of Enterobacter cowanii from Eucalyptus showing symptoms of bacterial blight and dieback in Uruguay.

AIMS: This study was performed to identify bacterial strains isolated simultaneously with Pantoea species from Eucalyptus trees showing symptoms of bacterial blight and dieback in Uruguay. METHODS AND RESULTS: Several molecular techniques including 16S rRNA and rpoB gene sequencing and DNA-DNA hybridization were used to characterize the gram-negative, facultatively anaerobic, slime-producing bacterial strains isolated along with Pantoea species from Eucalyptus. Hypersensitivity reactions (HR) and pathogenicity tests were performed on tobacco and Eucalyptus seedlings, respectively. The isolates clustered closely with the type strain of Enterobacter cowanii in both phylogenetic trees constructed. The DNA-DNA similarity between the isolates and the type strain of Ent. cowanii ranged from 88% to 92%. A positive HR was observed on the tobacco seedlings, but no disease symptoms were visible on the inoculated Eucalyptus seedlings. CONCLUSIONS: Enterobacter cowanii was isolated from trees with symptoms of bacterial blight although strains of this bacterial species do not appear to be the causal agent of the disease. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides the first report of Ent. cowanii isolated from Eucalyptus. Its presence in Eucalyptus tissue suggests that it is an endophyte in trees showing symptoms of blight.

Prevalence of bacterial pathogens in biofilms of drinking water distribution systems.

Water for human consumption is required to be free from any bacteria that might pose a health risk. The presence of biofilms in the drinking water distribution system may play a role in the presence of potential pathogens in the drinking water supply. Ninety-five biofilm samples from various parts of South Africa were tested for the presence of Escherichia coli, Aeromonas, Pseudomonas, Salmonella, Shigella and Vibrio spp. Members of these genera were quantified by the three-tube most probable number (MPN) approach using enrichment broths and plating on selective agars. The heterotrophic culturable counts were determined for both the planktonic and biofilm phases of the samples. Biofilm density varied between 10 and 1.9 x 10(9) colony forming units cm(-2). The 16S rRNA identity of the putative pathogenic isolates revealed that high numbers of Aeromonas, Pseudomonas, Klebsiella and Enterobacter were present, but no putative Salmonella and Shigella could be confirmed. None of the Pseudomonas isolates belonged to the pathogenic Pseudomonas aeruginosa or Pseudomonas mendocina while the Aeromonas isolates showed relatedness to known pathogenic members of this group.

Isolation and Identification of the Causal Agent of Brown Stalk Rot, A New Disease of Maize in South Africa.

During 2004 to 2005, an unreported disease of maize (Zea mays) was observed on commercial fields in the Northwest and Mpumalanga Provinces of South Africa. Infected plants were stunted, with a vertical crack at the first internode. Inside the stem, a dark-brown, narrow lesion was present along the crack. Internal browning inside the stem extended upward, reaching the top internode in some plants. Seed cobs were underdeveloped. Diseased plants were scattered in the fields and 10 to 70% of the crop was affected. Gram-negative, facultatively anaerobic bacteria were consistently isolated from diseased tissues. Pathogenicity tests established that representative strains induced disease symptoms similar to those observed on maize plants in the field. Physiological and biochemical characterization using the API 20E and API 50CHE systems and 16S rRNA gene sequence analyses showed that the strains belonged to the genus Pantoea. The results of these tests also separated the strains into two groups. The first group, giving a positive reaction in the indole test, was similar to Pantoea ananatis. The second group of strains was indole negative and resembled P. agglomerans. The fluorescent amplified fragment length polymorphism (F-AFLP) genomic fingerprints generated by the indole-positive strains and P. ananatis reference strains were similar and clustered together in the dendrogram, confirming that the indole-positive bacteria causing brown stalk rot on maize were P. ananatis. The F-AFLP fingerprints produced by the indole-negative strains were distinctly different from those generated by P. ananatis, P. agglomerans, P. dispersa, P. citrea, P. stewartii subsp. stewartii, and P. stewartii subsp. indologenes. The results indicated that indole-negative bacteria causing brown stalk rot on maize might belong to a previously undescribed species of the genus Pantoea. This is the first report of a new disease on maize, brown stalk rot, caused by two bacterial species, P. ananatis and an undescribed Pantoea sp.

Significance of bacteria associated with invertebrates in drinking water distribution networks.

The implication of invertebrates found in drinking water distribution networks to public health is of concern to water utilities. Previous studies have shown that the bacteria associated with the invertebrates could be potentially pathogenic to humans. This study investigated the level and identity of bacteria commonly associated with invertebrates collected from the drinking water treatment systems as well as from the main pipelines leaving the treatment works. On all sampling occasions bacteria were isolated from the invertebrate samples collected. The highest bacterial counts were observed for the samples taken before filtration as was expected. There were, however, indications that optimal removal of invertebrates from water did not always occur. During the investigation, 116 colonies were sampled for further identification. The isolates represent several bacterial genera and species that are pathogenic or opportunistic pathogens of humans. Diarrhoea, meningitis, septicaemia and skin infections are among the diseases associated with these organisms. The estimated number of bacteria that could be associated with a single invertebrate (as based on average invertebrate numbers) could range from 10 to 4000 bacteria per organism. It can, therefore, be concluded that bacteria associated with invertebrates might under the worst case scenario pose a potential health risk to water users. In the light of the above findings it is clear that invertebrates in drinking water should be controlled at levels as low as technically and economically feasible.

Diversity of nontuberculoid Mycobacterium species in biofilms of urban and semiurban drinking water distribution systems.

Nontuberculous mycobacteria (NTM) are ubiquitous and have been isolated from a variety of environmental sources, including water. Various NTM were isolated from biofilms in drinking water distribution systems in two urban and two semiurban areas in South Africa. Most of the isolates belonged to opportunistic pathogenic species of the NTM group, but none belonged to the Mycobacterium avium complex.

Evaluation of a rapid polymerase chain reaction based identification technique for Vibrio cholerae isolates.

Rapid and accurate identification of waterborne pathogens, such as Vibrio cholerae, in drinking-water sources is important to enable effective resource management and public health protection. Phenotypic systems currently being used for the identification of Vibrio cholerae isolates are time-consuming and the need exists for the development of suitable molecular techniques that can offer both fast and reliable identification. During this study, isolates identified as Vibrio cholerae by means of two different biochemical test systems (API 20E and VITEK 32) were analysed with the polymerase chain reaction (PCR) to compare the reliability of the various identification systems. The selected PCR technique amplified a sequence within the outer membrane protein of Vibrio cholerae, a gene specific for V. cholerae. It was found that out of 243 isolates biochemically identified as V. cholerae with either the API or VITEK system, 21 isolates did not give a positive result with the PCR detection method. Sequencing the 16S rDNA of more than half of these isolates and comparison of the sequences with Internet databases indicated that most of the isolates belonged to the genus Aeromonas. The results indicated that the rapid PCR procedure was more accurate than the API or VITEK systems currently being used for the phenotypic identification of Vibrio cholerae isolates.

The occurrence of campylobacters in water sources in South Africa.

Campylobacter spp., mainly C. jejuni and C. coli, are recognized as significant human bacterial pathogens, being responsible for increasing numbers of gastroenteritis cases worldwide. Several reports have indicated that environmental waters are potential reservoirs and transmitting vehicles for these bacteria. The purpose of this study was thus to examine the occurrence of campylobacters in drinking and environmental water sources of South Africa, a country with a warmer climate and higher microbial pollution levels than those previously addressed in the Northern Hemisphere where similar investigations have been undertaken. Various types of water samples (five drinking water, four ground water, 11 surface water and four raw sewage) were collected from different parts of South Africa. Detection was by enrichment in Bolton broth prior to plating on both selective mCCDA or through a 0.6microm membrane filter on non-selective blood agar isolation media. Out of 100 initially selected Campylobacter-like isolates, only 22 did not grow aerobically and were subsequently identified as Campylobacter spp. by biochemical tests. However, the results obtained by 16S rRNA sequence analysis indicated that only three of these strains (13.6%) were Campylobacter jejuni and the remaining 19 strains were identified as Arcobacter butzleri. The spread of Arcobacter via water warrants further investigation, especially in view of the higher levels of detection and pathogenic nature of these bacteria.

Identification methods for Legionella from environmental samples.

Laboratories responsible for Legionella diagnostics around the world use a number of different culturing methods of non-equivalent sensitivities and specificities, to detect Legionella species in environmental samples. Specific countries usually standardize and use one approved method. For example, laboratories in Australia use the Australian Standard (AS) method and those in Europe, the International Standard method (ISO). However, no standard culturing methods have been established in South Africa to date. As a result, there is uncertainty about the true prevalence and most common species of Legionella present in the South African environment. In an attempt to provide guidelines for the development of a standard method specific for South Africa, the ISO, AS and a most probable number method were evaluated and compared. In addition, the effect of sample re-incubation with autochthonous amoebae on culture outcome was studied. Samples were collected from four environments, representing industrial water, mine water and biofilm. The samples were concentrated by membrane filtration and divided into three portions and cultured without pretreatment, after acid treatment and after heat treatment, on four culture media namely alphaBCYE, BMPA, MWY and GVPC agar. A selective approach, incorporating heat treatment, but not acid treatment, combined with culture on alphaBCYE and GVPC or MWY, was most appropriate for legionellae detection in the samples evaluated. Legionellae were cultured from 82% of the environmental samples we evaluated. In 54% of the samples tested, legionellae were present in numbers equal to or exceeding 10(2) colony-forming units per milliliter (cfu/ml). Legionella pneumophila serogroups (SGs) 1-14 were the most prevalent species and were present as single, or a combination of two or more SGs in a number of samples tested. Re-incubation of sample concentrates with autochthonous amoebae improved the culturability of legionellae in 50% of cultures on alphaBCYE and 25% on GVPC.

A sensitive seminested PCR method for the detection of Shigella in spiked environmental water samples.

A rapid seminested polymerase chain reaction (PCR) method for the specific, sensitive detection of virulent Shigella spp. in spiked environmental water samples was developed. A set of primers specific for the invasion plasmid antigen gene (ipaH) of virulent Shigella spp. and enteroinvasive Escherichia coli produced a 620-bp fragment that was used as template for the seminested primer pair delineating a 401-bp fragment. By using agarose gel electrophoresis for detection of the seminested PCR-amplified products, a detection limit of 1.6 x 10(3) cfu S. flexneri was obtained with amplification reactions from crude bacterial lysates. The PCR procedure coupled with an enrichment culture incubated for 6 h detected as few as 1.6 S. flexneri organisms in pure culture. Treated sewage, ground, surface and drinking water samples collected from various sources were seeded with S. flexneri and incubated in GN broth for 6 h before detection by seminested PCR. A detection limit lower than 14 cfu/ml was achieved in some water samples. The results indicate that the described seminested PCR has the advantage of a rapid turnaround time and it fulfills the requirements of sensitivity and specificity for use in an environmental laboratory.

Detection of toxigenic Vibrio cholerae from environmental water samples by an enrichment broth cultivation-pit-stop semi-nested PCR procedure.

A pit-stop semi-nested PCR assay for the detection of toxigenic Vibrio cholerae in environmental water samples was developed and its performance evaluated. The PCR technique amplifies sequences within the cholera toxin operon specific for toxigenic V. cholerae. The PCR procedure coupled with an enrichment culture detected as few as four V. cholerae organisms in pure culture. Treated sewage, surface, ground and drinking water samples were seeded with V. cholerae and following enrichment, a detection limit of as few as 1 V. cholerae cfu ml(-1) was obtained with amplification reactions from crude bacterial lysates. The proposed method, which includes a combination of enrichment, rapid sample preparation and a pit-stop semi-nested PCR, could be applicable in the rapid detection of toxigenic V. cholerae in environmental water samples.